Advertisement

Resilience and Adverse Childhood Experiences: Associations With Poor Mental Health Among Homeless Adults

  • Michael Liu
    Affiliations
    Harvard Medical School, Boston, Massachusetts

    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada
    Search for articles by this author
  • Cilia Mejia-Lancheros
    Affiliations
    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada
    Search for articles by this author
  • James Lachaud
    Affiliations
    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada
    Search for articles by this author
  • Rosane Nisenbaum
    Affiliations
    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada

    Division of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
    Search for articles by this author
  • Vicky Stergiopoulos
    Affiliations
    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada

    Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada

    Center for Addiction and Mental Health, Toronto, Ontario, Canada
    Search for articles by this author
  • Stephen W. Hwang
    Correspondence
    Address correspondence to: Stephen W. Hwang, MD, MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, St. Michael's Hospital, 30 Bond Street, Toronto, Ontario M5B 1W8, Canada.
    Affiliations
    MAP Center for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto, Toronto, Ontario, Canada

    Division of General Internal Medicine, Department of Medicine, University of Toronto, Toronto, Ontario, Canada
    Search for articles by this author

      Introduction

      Adverse childhood experiences are known risk factors for a range of social, economic, and health-related outcomes over the life course. Resilience is a known protective factor. This study examines the associations of adverse childhood experiences and resilience with poor mental health outcomes among homeless adults with mental illness.

      Methods

      This study utilized data from 565 homeless adults with mental illness participating in a Housing First intervention in Toronto (2009–2013) to evaluate their sociodemographic characteristics, adverse childhood experience exposure, resilience, and mental health outcomes. Descriptive statistics were generated, and logistic regression models were used to examine the association of total adverse childhood experience score and resilience with poor mental health outcomes. Analyses were conducted in 2019.

      Results

      The average total adverse childhood experience score was 4.1 (SD=2.8) among all study participants. Individuals with a lifetime duration of homelessness exceeding 36 months (p=0.011) had higher mean scores. Total score was positively associated with several mental illness diagnoses and psychopathology severity, indicated by co-occurring mental illness diagnoses (AOR=1.23, 95% CI=1.13, 1.33) and high Colorado Symptom Index scores (AOR=1.26, 95% CI=1.14, 1.38). Resilience served as a protective factor against several individual mental illness diagnoses, co-occurring mental illness diagnoses (AOR=0.85, 95% CI=0.76, 0.95), and high Colorado Symptom Index scores (AOR=0.69, 95% CI=0.61, 0.79).

      Conclusions

      Findings highlight the high prevalence of adverse childhood experiences and their negative impact on homeless adults with mental illness. Resilience protects against adverse childhood experience–associated poor mental health outcomes, thereby serving as a potential interventional target in homeless populations.

      INTRODUCTION

      A wealth of existing evidence has revealed strong associations between adverse childhood experiences (ACEs) and social, economic, and health-related outcomes over the life course.
      • Corso PS
      • Edwards VJ
      • Fang X
      • Mercy JA
      Health-related quality of life among adults who experienced maltreatment during childhood.
      • Anda RF
      • Felitti VJ
      • Bremner JD
      • et al.
      The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.
      • Dube SR
      • Anda RF
      • Felitti VJ
      • Chapman DP
      • Williamson DF
      • Giles WH
      Childhood abuse, household dysfunction, and the risk of attempted suicide throughout the life span: findings from the Adverse Childhood Experiences study.
      These ACEs include physical, sexual, and emotional abuse; neglect; and household dysfunction. In the pioneering Centers for Disease Control and Prevention–Kaiser study, adults in a California HMO exposed to ACEs were much more likely to have poor physical, mental, and behavioral health outcomes.
      • Felitti VJ
      • Anda RF
      • Nordenberg D
      • et al.
      Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study.
      For mental health, strong associations have been reported between ACEs and mood disorders, personality disorders, suicidality, and other psychiatric disorders.
      • Dube SR
      • Anda RF
      • Felitti VJ
      • Chapman DP
      • Williamson DF
      • Giles WH
      Childhood abuse, household dysfunction, and the risk of attempted suicide throughout the life span: findings from the Adverse Childhood Experiences study.
      ,
      • Schilling EA
      • Aseltine RH
      • Gore S
      Adverse childhood experiences and mental health in young adults: a longitudinal survey.
      • Chapman DP
      • Whitfield CL
      • Felitti VJ
      • Dube SR
      • Edwards VJ
      • Anda RF
      Adverse childhood experiences and the risk of depressive disorders in adulthood.
      • Horwitz AV
      • Widom CS
      • McLaughlin J
      • White HR
      The impact of childhood abuse and neglect on adult mental health: a prospective study.
      Several studies and meta-analyses have revealed a dose–response relationship between total ACE score and poor later-life outcomes in the general population.
      • Green JG
      • McLaughlin KA
      • Berglund PA
      • et al.
      Childhood adversities and adult psychiatric disorders in the national comorbidity survey replication I: associations with first onset of DSM-IV disorders.
      • Bellis MA
      • Hughes K
      • Ford K
      • Ramos Rodriguez G
      • Sethi D
      • Passmore J
      Life course health consequences and associated annual costs of adverse childhood experiences across Europe and North America: a systematic review and meta-analysis.
      • Hughes K
      • Bellis MA
      • Hardcastle KA
      • et al.
      The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.
      For example, adults exposed to 1, 4, and 7 or more ACEs are 1.7, 3.9, and 17.0 times more likely to have attempted suicide than those exposed to no ACEs.
      • Dube SR
      • Anda RF
      • Felitti VJ
      • Chapman DP
      • Williamson DF
      • Giles WH
      Childhood abuse, household dysfunction, and the risk of attempted suicide throughout the life span: findings from the Adverse Childhood Experiences study.
      The results of most ACE studies—primarily focused on adults with stable housing and private insurance—cannot be generalized to homeless adults with mental illness.
      • Felitti VJ
      • Anda RF
      • Nordenberg D
      • et al.
      Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study.
      ,
      • Dube SR
      • Williamson DF
      • Thompson T
      • Felitti VJ
      • Anda RF
      Assessing the reliability of retrospective reports of adverse childhood experiences among adult HMO members attending a primary care clinic.
      This demographic faces a double burden from early adversities; in addition to the association of ACEs with psychopathology severity,
      • Anda RF
      • Felitti VJ
      • Bremner JD
      • et al.
      The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.
      ACEs have been linked to increased risk of homelessness through fragmented familial ties, decreased social support, and limitations in education and employment.
      • Roos LE
      • Mota N
      • Afifi TO
      • Katz LY
      • Distasio J
      • Sareen J
      Relationship between adverse childhood experiences and homelessness and theimpact of Axis I and II disorders.
      A few studies have reported associations between childhood adversities and suicidality, substance abuse, depressive symptoms, and psychiatric hospitalization among homeless adults.
      • Lee CM
      • Mangurian C
      • Tieu L
      • Ponath C
      • Guzman D
      • Kushel M
      Childhood adversities associated with poor adult mental health outcomes in older homeless adults: results from the HOPE HOME Study.
      • Brown RT
      • Goodman L
      • Guzman D
      • Tieu L
      • Ponath C
      • Kushel MB
      Pathways to homelessness among older homeless adults: results from the HOPE HOME study.
      • Stein JA
      • Leslie MB
      • Nyamathi A
      Relative contributions of parent substance use and childhood maltreatment to chronic homelessness, depression, and substance abuse problems among homeless women: mediating roles of self-esteem and abuse in adulthood.
      • Torchalla I
      • Strehlau V
      • Li K
      • Schuetz C
      • Krausz M
      The association between childhood maltreatment subtypes and current suicide risk among homeless men and women.
      • Tam TW
      • Zlotnick C
      • Robertson MJ
      Longitudinal perspective: adverse childhood events, substance use, and labor force participation among homeless adults.
      • Patterson ML
      • Moniruzzaman A
      • Somers JM
      Setting the stage for chronic health problems: cumulative childhood adversity among homeless adults with mental illness in Vancouver, British Columbia.
      Studies of individuals at risk for ACE-associated problems have found considerable variability in later-life outcomes.
      • Masten AS
      Ordinary magic: resilience processes in development.
      ,
      • Masten AS
      • Best KM
      • Garmezy N
      Resilience and development: contributions from the study of children who overcome adversity.
      Resilience—the capacity to “adapt successfully to challenges that threaten function, survival, or future development”—is one variable that facilitates positive developmental trajectories despite early trauma.
      • Bonnano GA
      Loss, trauma, and human resilience. Have we underestimated the human capacity to thrive after extremely aversive events?.
      Resilience has been found to protect against psychopathology in diverse contexts of trauma.
      • Kim-Cohen J
      Resilience and developmental psychopathology.
      ,
      • Sameroff AJ
      Developmental systems and psychopathology.
      To the authors’ knowledge, no studies have examined resilience as a protective factor against ACE-associated poor mental health outcomes among homeless adults.
      This study investigates whether ACEs serve as risk factors for poor mental health outcomes among homeless adults with mental illness. It also asks whether resilience serves as a protective factor against such outcomes. Altogether, these investigations might inform novel prevention and intervention strategies to enhance resilience capacities and ameliorate the negative impact of early adversities among this vulnerable population.

      METHODS

      Study Population

      The At Home/Chez Soi Project was an RCT of a Housing First intervention for homeless adults with mental illness in 5 Canadian cities.
      • Goering PN
      • Streiner DL
      • Adair C
      • et al.
      The At Home/Chez Soi trial protocol: a pragmatic, multi-site, randomised controlled trial of a Housing first intervention for homeless individuals with mental illness in five Canadian cities.
      This study examined data from 1 study site (Toronto). Trial details have been reported elsewhere.
      • Hwang SW
      • Stergiopoulos V
      • O'Campo P
      • Gozdzik A
      Ending homelessness among people with mental illness: the At Home/Chez Soi randomized trial of a Housing first intervention in Toronto.
      The At Home/Chez Soi inclusion criteria were as follows: (1) age ≥18 years, (2) either absolute homelessness or precarious housing, and (3) presence of a serious mental disorder.
      • Hwang SW
      • Stergiopoulos V
      • O'Campo P
      • Gozdzik A
      Ending homelessness among people with mental illness: the At Home/Chez Soi randomized trial of a Housing first intervention in Toronto.
      Serious mental disorders were identified by the DSM-IV criteria in the MINI International Neuropsychiatric Interview 6.0 (MINI).
      • Sheehan DV
      • Lecrubier Y
      • Sheehan KH
      • et al.
      The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10.
      Participants with at least 1 of the following diagnoses were considered eligible for the study: (1) major depressive disorder, (2) manic or hypomanic episode, (3) mood disorder with psychotic features, (4) panic disorder, (5) post-traumatic stress disorder (PTSD), and (6) psychotic disorder. The study was approved by the Research Ethics Board of St. Michael's Hospital in Toronto and was registered with the International Standard RCT Number (ISRCTN42520374).
      The study recruited participants through referral from >80 agencies providing services to individuals experiencing homelessness or mental illness. This extensive network included shelters, hospitals, outreach programs, and community health centers. Information related to sociodemographics, housing, health, and resilience were collected using validated questionnaires.
      • Hwang SW
      • Stergiopoulos V
      • O'Campo P
      • Gozdzik A
      Ending homelessness among people with mental illness: the At Home/Chez Soi randomized trial of a Housing first intervention in Toronto.
      The following analyses were based upon data from 565 participants recruited between October 2009 and June 2011. Note that 10 transgender participants were excluded from the analyses as this sample size precluded multivariable analysis. In addition, associations between ACEs and later health outcomes are unique for transgender individuals and would not be captured adequately in these analyses.
      • Andersen JP
      • Blosnich J
      Disparities in adverse childhood experiences among sexual minority and heterosexual adults: results from a multi-state probability-based sample.
      • Schneeberger AR
      • Dietl MF
      • Muenzenmaier KH
      • Huber CG
      • Lang UE
      Stressful childhood experiences and health outcomes in sexual minority populations: a systematic review.
      • Mustanski B
      • Andrews R
      • Puckett JA
      The effects of cumulative victimization on mental health among lesbian, gay, bisexual, and transgender adolescents and young adults.

      Measures

      Total ACE score was the main risk factor in this study. ACEs were assessed 18 months after the baseline interview using the ACE scale, consisting of questions related to trauma experienced before age 18 years.
      • Felitti VJ
      • Anda RF
      • Nordenberg D
      • et al.
      Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study.
      The ACE scale includes 10 total categories: 3 categories of childhood abuse (emotional, physical, and sexual), 2 categories of neglect (emotional and physical), and 5 categories of household dysfunction (parental separation/divorce, household mental illness, domestic violence against women, household criminal justice involvement, and household substance abuse). Participants received 1 point for a category if they responded yes to 1 or more questions in a particular category, for a maximum total score of 10. The ACE scale has good test–retest reliability and retrospective–prospective reporting agreement.
      • Dube SR
      • Williamson DF
      • Thompson T
      • Felitti VJ
      • Anda RF
      Assessing the reliability of retrospective reports of adverse childhood experiences among adult HMO members attending a primary care clinic.
      ,
      • Reuben A
      • Moffitt TE
      • Caspi A
      • et al.
      Lest we forget: comparing retrospective and prospective assessments of adverse childhood experiences in the prediction of adult health.
      Resilience was the main protective factor in this study. The Connor–Davidson Resilience Scale 2, a 2-item scale with possible scores between 0 and 8, was used to measure resilience.
      • Vaishnavi S
      • Connor K
      • Davidson JRT
      An abbreviated version of the Connor-Davidson Resilience Scale (CD-RISC), the CD-RISC2: psychometric properties and applications in psychopharmacological trials.
      ,
      • Connor KM
      • Davidson JRT
      Development of a new resilience scale: the Connor-Davidson Resilience scale (CD-RISC).
      Higher scores indicated greater resilience.
      The following mental health diagnoses were considered outcomes and assessed through the MINI
      • Sheehan DV
      • Lecrubier Y
      • Sheehan KH
      • et al.
      The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10.
      : (1) major depressive disorder, (2) manic or hypomanic episode, (3) PTSD, (4) panic disorder, (5) mood disorder with psychotic features, (6) psychotic disorder, (7) alcohol dependence, (8) substance dependence, (9) alcohol abuse, (10) substance abuse, and (11) suicidality. Response options to the suicidality module included: no, low, moderate, or high. To assess co-occurrence of mental disorders, an indicator variable was created to capture having 2 or more mental disorders. The Colorado Symptom Index score, measuring severity of self-reported psychiatric symptomology, was also considered as an outcome. It was measured through a 14-item Likert-type scale with possible scores between 0 and 70, with higher scores indicating greater symptom burden.
      • Conrad KJ
      • Yagelka JR
      • Matters MD
      • Rich AR
      • Williams V
      • Buchanan M
      Reliability and validity of a modified Colorado Symptom Index in a national homeless sample.
      To assess severe psychiatric symptomology, an indicator variable was created to capture a clinically relevant threshold of ≥30 points.
      • Boothroyd RA
      • Chen HJ
      The psychometric properties of the Colorado Symptom Index.
      Psychometric properties for all psychological measures are reported in Appendix Table 1, available online.

      Statistical Analysis

      Participants with any missing outcome, exposure, or covariate were deemed to be incomplete case participants. Comparisons of continuous variables between complete and incomplete case participants were conducted using Student's t-tests. Comparisons of categorical variables were conducted using Pearson's chi-square tests or Fisher's exact tests. Descriptive summaries of total ACE scores across all outcomes and covariates were generated.
      First, univariate and multivariable logistic regression analyses were used to model the unadjusted and adjusted associations between total ACE score and resilience with mental health outcomes for complete case participants (n=373). The following covariates were chosen based on previous literature: self-identified gender, age, ethnicity, education, and duration of homelessness.
      • Schilling EA
      • Aseltine RH
      • Gore S
      Adverse childhood experiences and mental health in young adults: a longitudinal survey.
      ,
      • Tam TW
      • Zlotnick C
      • Robertson MJ
      Longitudinal perspective: adverse childhood events, substance use, and labor force participation among homeless adults.
      ,
      • Edwards VJ
      • Anda RF
      • Nordenberg DF
      • Felitti VJ
      • Williamson DF
      • Wright JA
      Bias assessment for child abuse survey: factors affecting probability of response to a survey about childhood abuse.
      ,
      • Herman DB
      • Susser ES
      • Struening EL
      • Link BL
      Adverse childhood experiences: are they risk factors for adult homelessness?.
      The potential modification effect of resilience on the association between ACEs and mental health outcomes was assessed using an interaction term between total ACE score and resilience. Second, multiple imputation by chained equations (MICE) was used to infer missing data pertaining to total ACE score (127 missing), ethnicity (22 missing), education (24 missing), duration of homelessness (33 missing), resilience (77 missing), and Colorado Symptom Index score (23 missing). One hundred imputed data sets were generated by chained equations using the “mi estimate” program in Stata.
      • Graham JW
      • Olchowski AE
      • Gilreath TD
      How many imputations are really needed? Some practical clarifications of multiple imputation theory.
      This particular number was chosen to reduce Monte Carlo error and improve precision in estimation.
      • Graham JW
      • Olchowski AE
      • Gilreath TD
      How many imputations are really needed? Some practical clarifications of multiple imputation theory.
      ,
      • Royston P
      • White I
      Multiple Imputation by Chained Equations (MICE): implementation in Stata.
      MICE assumes that data are missing at random, such that systematic differences between missing and observed values can be explained by differences in the observed data.
      • Azur MJ
      • Stuart EA
      • Frangakis C
      • Leaf PJ
      Multiple imputation by chained equations: what is it and how does it work?.
      ,
      • Sterne JAC
      • White IR
      • Carlin JB
      • et al.
      Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls.
      All variables used in the analyses were included in the imputation models. Appropriateness of the imputation model and imputed values was confirmed using distribution plots, Kolmogorov–Smirnov tests, and tables of proportions.
      • Eddings W
      • Marchenko Y
      Diagnostics for multiple imputation in Stata.
      The imputation diagnostics for total ACE score are shown as an example in Appendix Figure 1 and Appendix Table 2, available online. Third, univariate and multivariable analyses were repeated to assess the associations between ACEs and resilience with mental health outcomes in the full imputed data sets (n=565). Results were similar to those observed from the complete case participant analyses. Thus, the regression analyses presented and discussed here are based on the imputed data sets.
      All p-values are two-sided. No adjustments for multiple testing were applied given interest in individual preplanned hypotheses.
      • Rothman KJ
      No adjustments are needed for multiple comparisons.
      • Streiner DL
      • Norman GR
      Correction for multiple testing: is there a resolution?.
      • Armstrong RA
      When to use the Bonferroni correction.
      Moreover, in accordance with recent guidelines, effect sizes are reported as unadjusted ORs and AORs with 95% CIs.
      • Harrington D
      • D'Agostino RB
      • Gatsonis C
      • et al.
      New guidelines for statistical reporting in the journal.
      All analyses were conducted in 2019 using Stata, version 16.

      RESULTS

      Of the 565 participants in the total sample, 484 participants (86%) completed the 18-month follow-up interview and 373 (77%) of these participants had a complete set of valid responses. Appendix Table 2, available online, presents the baseline characteristics for the full sample (n=565) and the complete (n=373) and incomplete case (n=192) participants. Complete case participants were more likely to be diagnosed with substance abuse than incomplete case participants. Incomplete case participants were more likely to be diagnosed with psychotic disorder than complete case participants. Otherwise, there were no other significant differences at baseline between participants with complete and incomplete data. In the overall baseline sample (n=565), most participants were male (70%) and either black (35%) or white (35%); the mean age at enrollment was 40.4 (SD=11.8) years. Additionally, 47% of participants did not complete high school and 53% had experienced a lifetime duration of homelessness >36 months. The mean baseline resilience score was 5.06 (SD=2.00).
      Table 1 summarizes ACEs among participants. The least common reported ACE was having household criminal justice involvement (26%), whereas the most common were emotional and physical abuse (57%). One third (33%) of participants had been sexually abused (an adult touching or fondling the participant; forcing the participant to touch him/her; or attempting to have oral, anal, or vaginal intercourse with the participant). More than half (55%) of participants experienced 4 or more ACEs and only 13% of participants had never experienced an ACE. The mean total ACE score was 4.1 (SD=2.8).
      Table 1Prevalence of ACEs Among Toronto At Home Study Participants (n=373)
      Variablen (%)
      Total ACE score
       047 (13)
       140 (11)
       237 (10)
       341 (11)
       439 (10)
       544 (12)
       638 (10)
       736 (10)
       822 (6)
       921 (5)
       108 (2)
       Mean (SD)4.1 (2.8)
       Median (range)4 (0‒10)
      Maltreatment
       Sexual abuse (n=363)
      Number of participants who provided a valid response to each item on ACE inventory. ACE, adverse childhood experience.
      121 (33)
       Emotional abuse (n=370)210 (57)
       Physical abuse (n=367)209 (57)
       Emotional neglect (n=363)188 (52)
       Physical neglect (n=369)126 (34)
      Household dysfunction
       Parental separation/divorce (n=363)172 (48)
       Domestic violence (n=355)132 (37)
       Household mental illness (n=359)125 (35)
       Household criminal justice involvement (n=363)93 (26)
       Household substance abuse (n=368)160 (44)
      a Number of participants who provided a valid response to each item on ACE inventory.ACE, adverse childhood experience.
      Summaries of total ACE scores across all outcomes and covariates are presented in Table 2. Aboriginal individuals (p<0.001) and those who experienced a lifetime duration of homelessness >36 months (p=0.011) were more likely to have higher ACE scores. Participants with negative mental health outcomes, including PTSD (p<0.001), panic disorder (p=0.004), mood disorder with psychotic features (p=0.004), alcohol dependence (p<0.001), substance dependence (p<0.001), more than 2 mental disorders (p<0.001), high suicidality (p<0.001), and severe psychiatric symptomology (p<0.001) had higher ACE scores than those without. Conversely, participants diagnosed with psychotic disorder had lower ACE scores than those without (p=0.018).
      Table 2Total ACE Score by Sociodemographic Characteristics and Mental Health Outcomes for Toronto At Home Study Participants (n=373)
      VariablesMean (SD)p-value
      Sociodemographic characteristics
       Gender0.274
        Male4.01 (2.75)
        Female4.37 (3.01)
       Age, years0.184
        18‒244.05 (2.28)
        25‒444.41 (2.99)
        >443.84 (2.77)
       Ethnicity
      p-value corresponds to one-way ANOVA test. Pairwise t-tests were performed with the following p-values: 0.011* for aboriginal vs black, <0.001*** for aboriginal vs other, 0.194 for aboriginal vs white, 1.00 for black vs other, 0.355 for black vs white, and 0.009*** for other vs white. ACE, adverse childhood experience; PTSD, post-traumatic stress disorder.
      <0.001***
        White4.64 (2.92)
        Black3.93 (2.71)
        Aboriginal6.10 (2.63)
        Other3.41 (2.79)
       Education0.058
        Complete high school3.87 (2.80)
        Incomplete high school4.42 (2.85)
       Duration of homelessness0.011*
        ≥36 months4.48 (2.88)
        <36 months3.74 (2.73)
      Mental health outcomes
       Major depressive disorder0.449
        Yes4.27 (2.87)
        No4.04 (2.81)
       Manic or hypomanic episode0.696
        Yes4.29 (3.04)
        No4.10 (2.80)
       PTSD<0.001***
        Yes5.10 (2.98)
        No3.81 (2.71)
       Panic disorder0.004**
        Yes5.23 (3.04)
        No3.93 (2.75)
       Mood disorder with psychotic features0.004**
        Yes4.98 (2.88)
        No3.90 (2.78)
       Psychotic disorder0.018*
        Yes3.67 (2.57)
        No4.36 (2.94)
       Alcohol dependence<0.001***
        Yes5.10 (2.80)
        No3.70 (2.75)
       Substance dependence<0.001***
        Yes5.15 (2.53)
        No3.50 (2.83)
       Alcohol abuse0.477
        Yes3.90 (2.60)
        No4.17 (2.88)
       Substance abuse0.513
        Yes3.87 (2.78)
        No4.16 (2.84)
       ≥2 mental disorders<0.001***
        Yes4.56 (2.81)
        No3.11 (2.62)
       High suicidality<0.001***
        Yes5.78 (2.60)
        No3.92 (2.80)
       Colorado Symptom Index ≥30<0.001***
        Yes4.45 (2.76)
        No2.92 (2.78)
      Note: Boldface indicates statistical significance (*p≤0.05; **p≤0.01; ***p≤0.001).
      a p-value corresponds to one-way ANOVA test. Pairwise t-tests were performed with the following p-values: 0.011* for aboriginal vs black, <0.001*** for aboriginal vs other, 0.194 for aboriginal vs white, 1.00 for black vs other, 0.355 for black vs white, and 0.009*** for other vs white.ACE, adverse childhood experience; PTSD, post-traumatic stress disorder.
      Unadjusted ORs, AORs, and 95% CIs for outcome variables included in the univariate (Model 1) and multivariable (Model 2) logistic regression analyses are presented in Table 3. Results from these analyses revealed that total ACE score was positively associated with the following poor mental health outcomes: PTSD (AOR=1.17, 95% CI=1.08, 1.27), panic disorder (AOR=1.15, 95% CI=1.04, 1.27), mood disorder with psychotic features (AOR=1.16, 95% CI=1.06, 1.28), alcohol dependence (AOR=1.21, 95% CI=1.11, 1.31), substance dependence (AOR=1.26, 95% CI=1.17, 1.37), more than 2 mental disorders (AOR=1.23, 95% CI=1.13, 1.33), high suicidality (AOR=1.26, 95% CI=1.13, 1.41), and severe psychiatric symptomology (AOR=1.26, 95% CI=1.14, 1.38).
      Table 3Regression Analyses for Mental Health Outcomes Based on Total ACE Score (n=565)
      Model 1Model 2
      Mental health outcome
      Separate binary logistic regression analyses (univariate and multivariable) were conducted for each outcome using total ACE score (continuous measure) as an independent variable.
      Unadjusted OR (95% CI)p-valueAOR (95% CI)
      Each multivariable model was controlled for age (continuous), gender (male vs female), ethnicity (aboriginal, white, black, or other), duration of homelessness (continuous), and education (complete vs incomplete high school). ACE, adverse childhood experience; PTSD, post-traumatic stress disorder.
      p-value
      Major depressive disorder1.06 (0.99, 1.13)0.0941.06 (0.99, 1.14)0.089
      Manic or hypomanic episode1.10 (1.00, 1.22)0.050*1.06 (0.96, 1.18)0.246
      PTSD1.19 (1.10, 1.28)<0.001***1.17 (1.08, 1.27)<0.001***
      Panic disorder1.15 (1.05, 1.26)0.002**1.15 (1.04, 1.27)0.004**
      Mood disorder with psychotic features1.14 (1.04, 1.24)0.003**1.16 (1.06, 1.28)0.001***
      Psychotic disorder0.91 (0.85, 0.97)0.006**0.91 (0.85, 0.98)0.012*
      Alcohol dependence1.22 (1.14, 1.32)<0.001***1.21 (1.11, 1.31)<0.001***
      Substance dependence1.29 (1.20, 1.39)<0.001***1.26 (1.17, 1.37)<0.001***
      Alcohol abuse0.97 (0.89, 1.06)0.5420.98 (0.89, 1.08)0.688
      Substance abuse0.97 (0.87, 1.08)0.5500.95 (0.85, 1.06)0.374
      ≥2 mental disorders1.25 (1.15, 1.35)<0.001***1.23 (1.13, 1.33)<0.001***
      High suicidality1.28 (1.15, 1.43)<0.001***1.26 (1.13, 1.41)<0.001***
      Colorado Symptom Index ≥301.24 (1.13, 1.35)<0.001***1.26 (1.14, 1.38)<0.001***
      Note: Boldface indicates statistical significance (*p≤0.05; **p≤0.01; ***p≤0.001). Analyses were conducted on 100 imputed datasets.
      a Separate binary logistic regression analyses (univariate and multivariable) were conducted for each outcome using total ACE score (continuous measure) as an independent variable.
      b Each multivariable model was controlled for age (continuous), gender (male vs female), ethnicity (aboriginal, white, black, or other), duration of homelessness (continuous), and education (complete vs incomplete high school).ACE, adverse childhood experience; PTSD, post-traumatic stress disorder.
      The AORs and 95% CIs for outcome variables included in the multivariable analyses with resilience added (Model 3) are presented in Figure 1. There was no significant interaction or correlation (r = −0.00031) between resilience and total ACE score. Resilience served as a protective factor against the following poor mental health outcomes: major depressive disorder (AOR=0.84, 95% CI=0.77, 0.93), PTSD (AOR=0.89, 95% CI=0.79, 0.99), mood disorder with psychotic features (AOR=0.88, 95% CI=0.79, 0.99), more than 2 mental disorders (AOR=0.85, 95% CI=0.76, 0.95), and severe psychiatric symptomology (AOR=0.69, 95% CI=0.61, 0.79).
      Figure 1
      Figure 1Resilience serves as a protective factor against ACE-associated poor mental health outcomes (n=565). Boldface indicates statistical significance (*p≤0.05; **p≤0.01; ***p≤0.001). Analyses were conducted on 100 imputed datasets. Each multivariable model was controlled for resilience (continuous), age (continuous), gender (male vs female), ethnicity (aboriginal, white, black, or other), duration of homelessness (continuous), and education (complete vs incomplete high school). ACE, adverse childhood experience.

      DISCUSSION

      These findings suggest strong associations between early adversities and poor mental health outcomes in a sample of homeless adults with mental illness. Total ACE score was positively associated with severity of psychopathology, as indicated by co-occurring mental disorders and high Colorado Symptom Index scores. These results are consistent with past investigations of ACEs among homeless adults. Patterson et al.
      • Patterson ML
      • Moniruzzaman A
      • Somers JM
      Setting the stage for chronic health problems: cumulative childhood adversity among homeless adults with mental illness in Vancouver, British Columbia.
      reported comparable associations among total ACE score and suicidality, alcohol dependence, and substance dependence among homeless adults with mental illness in Vancouver. Another study looked at cumulative associations among 5 types of childhood maltreatment and suicidality among elderly homeless adults, reporting comparable AORs (1.41 and 2.93, respectively).
      • Stein JA
      • Leslie MB
      • Nyamathi A
      Relative contributions of parent substance use and childhood maltreatment to chronic homelessness, depression, and substance abuse problems among homeless women: mediating roles of self-esteem and abuse in adulthood.
      This study contributes novel and clinically relevant insight into the associations among ACEs, psychopathology severity, and several DSM-IV psychiatric diagnoses.
      Perhaps more importantly, these findings uncover a protective effect of resilience against severity of psychopathology and several other poor mental health outcomes among homeless adults with mental illness. The protective effect of resilience has also been reported in other settings and populations. Among a sample of Korean firefighters, resilience buffered the impact of traumatic stress on PTSD symptoms.
      • Lee JS
      • Ahn YS
      • Jeong KS
      • Chae JH
      • Choi KS
      Resilience buffers the impact of traumatic events on the development of PTSD symptoms in firefighters.
      In another study of Irish adults, perceived social support—a key component of resilience—buffered the association between ACEs and later-life depression.
      • Cheong EV
      • Sinnott C
      • Dahly D
      • Kearney PM
      Adverse childhood experiences (ACEs) and later-life depression: perceived social support as a potential protective factor.
      ,
      • Cameron CA
      • Ungar M
      • Liebenberg L
      Cultural understandings of resilience: roots for wings in the development of affective resources for resilience.
      Current frameworks postulate that present day resilience allows individuals to overcome past adversity via enhanced emotional/cognitive processing, decreased intrusive rumination, and reduced perceptions of entrapment.
      • Davydov DM
      • Stewart R
      • Ritchie K
      • Chaudieu I
      Resilience and mental health.
      ,
      • Lee JS
      Perceived social support functions as a resilience in buffering the impact of trauma exposure on PTSD symptoms via intrusive rumination and entrapment in firefighters.
      Although there is evidence of resilience stability throughout the life course, resilience is a mutable trait that is reinforced and eroded by several factors.
      • Luthar SS
      • Cicchetti D
      • Becker B
      The construct of resilience: a critical evaluation and guidelines for future work.
      • Masten AS
      • Hubbard JJ
      • Gest SD
      • Tellegen A
      • Garmezy N
      • Ramirez M
      Competence in the context of adversity: pathways to resilience and maladaptation from childhood to late adolescence.
      • Egeland B
      • Carlson E
      • Sroufe LA
      Resilience as process.
      Future studies should seek to untangle how lifelong resilience and other protective factors buffer the sequelae of early life adversities.
      Trauma is a well-established risk factor for all mental health diagnoses found to be associated with total ACE score in this study.
      • Copeland WE
      • Keeler G
      • Angold A
      • Costello EJ
      Traumatic events and posttraumatic stress in childhood.
      ,
      • Kessler RC
      • Davis CG
      • Kendler KS
      Childhood adversity and adult psychiatric disorder in the U.S. National Comorbidity Survey.
      These analyses also revealed a positive association between total ACE score and alcohol and substance dependence, but not alcohol and substance abuse. The former categories reflect greater severity.
      • Hasin DS
      • O'Brien CP
      • Auriacombe M
      • et al.
      DSM-5 criteria for substance use disorders: recommendations and rationale.
      Past studies have suggested that alcohol and substance dependence arise from attempts to cope with early adversity.
      • Hays SP
      • Hays CE
      • Mulhall PF
      Community risk and protective factors and adolescent substance use.
      • Sinha R
      Chronic stress, drug use, and vulnerability to addiction.
      • Chen X
      • Tyler KA
      • Whitbeck LB
      • Hoyt DR
      Early sexual abuse, street adversity, and drug use among female homeless and runaway adolescents in the Midwest.
      Contrary to past reports, this study found that psychotic disorder was negatively associated with total ACE score.
      • Read J
      • Van Os J
      • Morrison AP
      • Ross CA
      Childhood trauma, psychosis and schizophrenia: a literature review with theoretical and clinical implications.
      • Varese F
      • Smeets F
      • Drukker M
      • et al.
      Childhood adversities increase the risk of psychosis: a meta-analysis of patient-control, prospective- and cross-sectional cohort studies.
      • Janssen I
      • Krabbendam L
      • Bak M
      • et al.
      Childhood abuse as a risk factor for psychotic experiences.
      However, it is important to note that patients with psychosis often have cognitive impairments and difficulties with reality testing, which might contribute to misreporting of early adversities.
      • Bendall S
      • Jackson HJ
      • Hulbert CA
      • McGorry PD
      Childhood trauma and psychotic disorders: a systematic, critical review of the evidence.
      • Lysaker PH
      • Beattie NL
      • Strasburger AM
      • Davis LW
      Reported history of child sexual abuse in schizophrenia: associations with heightened symptom levels and poorer participation over four months in vocational rehabilitation.
      • Deng M
      • Pan Y
      • Zhou L
      • et al.
      Resilience and cognitive function in patients with schizophrenia and bipolar disorder, and healthy controls.
      Other unknown factors might also influence the relationship between ACEs and psychotic disorders in this population, necessitating further research.
      The overall number and co-occurrence of ACEs among this sample was quite concerning. The average ACE score was 4.1, with 55% and 24% of participants having experienced 4 or more and 7 or more ACEs, respectively. These numbers are more than fourfold higher than those of the original ACE study, with only 12% and 0.9% of participants having experienced 4 or more and 7 or more ACEs, respectively.
      • Dube SR
      • Anda RF
      • Felitti VJ
      • Chapman DP
      • Williamson DF
      • Giles WH
      Childhood abuse, household dysfunction, and the risk of attempted suicide throughout the life span: findings from the Adverse Childhood Experiences study.
      These findings have several implications for policymakers and service providers. Given the high prevalence of ACEs among homeless adults with mental illness, service providers working with this population should prioritize ACE screening.
      • Browne A
      • Finkelhor D
      Impact of child sexual abuse. a review of the research.
      For those exposed to ACEs, these findings suggest that it might be possible to mitigate ACE-associated outcomes by promoting resilience. Resilience is amenable to intervention in adulthood; interventions have significantly improved resilience through course-based training, mindfulness, and well-being therapy.
      • Macedo T
      • Wilheim L
      • Gonçalves R
      • et al.
      Building resilience for future adversity: a systematic review of interventions in non-clinical samples of adults.
      • Greenberg MT
      Promoting resilience in children and youth: preventive interventions and their interface with neuroscience.
      • Galante J
      • Dufour G
      • Vainre M
      • et al.
      A mindfulness-based intervention to increase resilience to stress in university students (the Mindful Student Study): a pragmatic randomised controlled trial.
      • Gillham JE
      • Reivich KJ
      • Freres DR
      • et al.
      School-based prevention of depressive symptoms: a randomized controlled study of the effectiveness and specificity of the Penn Resiliency Program.
      • Fava GA
      • Tomba E
      Increasing psychological well-being and resilience by psychotherapeutic methods.
      Recent studies have also identified engagement in meaningful activities, social support, and personal strength as particular sources of resilience among homeless adults with mental illness.
      • Durbin A
      • Nisenbaum R
      • Kopp B
      • O'Campo P
      • Hwang SW
      • Stergiopoulos V
      Are resilience and perceived stress related to social support and housing stability among homeless adults with mental illness?.
      ,
      • Paul S
      • Corneau S
      • Boozary T
      • Stergiopoulos V
      Coping and resilience among ethnoracial individuals experiencing homelessness and mental illness.
      ACE screening and resilience building should be incorporated into standard practice within settings that provide care and support to homeless adults.
      It is even more important to address childhood adversities in youth and young adults. Early trauma interferes with normal development and increases exposure risk to future adversities, thereby perpetuating negative outcomes across the lifecourse.
      • Garner AS
      • Shonkoff JP
      Committee on Psychosocial Aspects of Child and Family Health, Committee on Early Childhood, Adoption, and Dependent Care, Section on Developmental and Behavioral Pediatrics
      Early childhood adversity, toxic stress, and the role of the pediatrician: translating developmental science into lifelong health.
      • Dawson G
      • Ashman SB
      • Carver LJ
      The role of early experience in shaping behavioral and brain development and its implications for social policy.
      • Mullen PE
      • Martin JL
      • Anderson JC
      • Romans SE
      • Herbison GP
      The long-term impact of the physical, emotional, and sexual abuse of children: a community study.
      • Callaghan BL
      • Tottenham N
      The stress acceleration hypothesis: effects of early-life adversity on emotion circuits and behavior.
      There should be a focus on prevention and treatment of ACEs at an early age. Several family-based intervention programs such as the Triple-P program and the Nurse–Family Partnership have successfully promoted the exposure of children to safe, stable, and nurturing early environments.
      • Garner AS
      • Shonkoff JP
      Committee on Psychosocial Aspects of Child and Family Health, Committee on Early Childhood, Adoption, and Dependent Care, Section on Developmental and Behavioral Pediatrics
      Early childhood adversity, toxic stress, and the role of the pediatrician: translating developmental science into lifelong health.
      ,
      • Olds D
      • Henderson CR
      • Cole R
      • et al.
      Long-term effects of nurse home visitation on children's criminal and antisocial behavior: 15-year follow-up of a randomized controlled trial.
      ,
      • Prinz RJ
      • Sanders MR
      • Shapiro CJ
      • Whitaker DJ
      • Lutzker JR
      Population-based prevention of child maltreatment: the U.S. Triple P System Population Trial.
      Individuals already exposed to ACEs should be referred to appropriate evidence-based treatments, including trauma-focused cognitive behavioral therapies and family therapies.
      • Cohen JA
      • Mannarino AP
      Trauma-focused cognitive behavioural therapy for children and parents.
      • Coulter S
      Systemic family therapy for families who have experienced trauma: a randomised controlled trial.
      • Cohen JA
      • Deblinger E
      • Mannarino AP
      • Steer RA
      A multisite, randomized controlled trial for children with sexual abuse-related PTSD symptoms.
      • Briere J
      • Scott C
      Complex trauma in adolescents and adults: effects and treatment.
      Comprehensive screening, prevention, and treatment efforts are necessary throughout the life course to mitigate the devastating detriments of ACEs.

      Limitations

      The main limitation of this study is that it cannot fully elucidate the causal pathways between ACEs and later-life outcomes. Though ACE exposure occurs early in life by definition, it is difficult to ascertain the temporal order of certain outcomes such as onset of homelessness and mental illness. Further longitudinal studies are required to understand how perceived stress, social support, and other indirect factors might influence the relationship between ACEs and poor mental health outcomes.
      • Logan-Greene P
      • Green S
      • Nurius PS
      • Longhi D
      Distinct contributions of adverse childhood experiences and resilience resources: a cohort analysis of adult physical and mental health.
      ,
      • Turner HA
      • Butler MJ
      Direct and indirect effects of childhood adversity on depressive symptoms in young adults.
      There are likely other mental health outcomes associated with ACEs that were not investigated in this study. For example, the MINI does not include personality disorders—diagnoses that are prevalent among homeless individuals and associated with ACEs.
      • Fazel S
      • Khosla V
      • Doll H
      • Geddes J
      The prevalence of mental disorders among the homeless in Western countries: systematic review and meta-regression analysis.
      ,
      • Afifi TO
      • Mather A
      • Boman J
      • et al.
      Childhood adversity and personality disorders: results from a nationally representative population-based study.
      Moreover, the MINI assesses only the presence and absence of psychiatric diagnoses. More precise understanding of the associations between ACEs and mental health outcomes would require information from psychopathology dimensions and symptom scales.
      • Pettersson A
      • Modin S
      • Wahlström R
      • Af Winklerfelt Hammarberg S
      • Krakau I
      The Mini-International Neuropsychiatric Interview is useful and well accepted as part of the clinical assessment for depression and anxiety in primary care: a mixed-methods study.
      In this study, ACE exposure was assessed retrospectively 18 months after the baseline interview. Although retrospective information is susceptible to recall bias, the ACE questionnaire has good test–retest reliability.
      • Dube SR
      • Williamson DF
      • Thompson T
      • Felitti VJ
      • Anda RF
      Assessing the reliability of retrospective reports of adverse childhood experiences among adult HMO members attending a primary care clinic.
      Nonetheless, there were a few participants who declined to respond to certain ACE modules, suggestive of the difficulties associated with recalling past trauma. Interestingly, past studies have found that retrospective ACE reporting often underestimates the influence of early adversities on objective health outcomes, including those assessed by neuropsychological tests.
      • Reuben A
      • Moffitt TE
      • Caspi A
      • et al.
      Lest we forget: comparing retrospective and prospective assessments of adverse childhood experiences in the prediction of adult health.
      ,
      • Maughan B
      • Rutter M
      Retrospective reporting of childhood adversity: issues in assessing long-term recall.
      There was a non-negligible amount of missing data in the study sample. Compared with list-wise deletion, MICE increases analysis efficiency and reduces bias.
      • Azur MJ
      • Stuart EA
      • Frangakis C
      • Leaf PJ
      Multiple imputation by chained equations: what is it and how does it work?.
      However, MICE assumes that data are missing at random and that the propensity of missingness can be explained by other covariates in the imputation model. This is much more defensible than the missing completely at random assumption required for list-wise deletion.
      • Kang H
      The prevention and handling of the missing data.
      However, it is not possible to definitely rule out that data were missing not at random.
      Finally, these analyses focused on homeless adults with mental illness in one Canadian city. More research is needed to understand the specific influence of ACEs and resilience on mental health outcomes in the general homeless population and in other geographic settings.

      CONCLUSIONS

      These findings reveal a high prevalence of early adversities among homeless adults with mental illness and strong positive associations of such adversities with several poor mental health outcomes. Moreover, resilience protects against these ACE-associated outcomes and might serve as a potential target for intervention. Coordinated efforts between families, healthcare professionals, service providers, and policymakers are needed to prevent and treat the lifelong sequelae of early adversities among this vulnerable population.

      ACKNOWLEDGMENTS

      First and foremost, the authors extend their sincere gratitude to the At Home/Chez Soi participants whose willingness to share their lives, experiences, and stories made this project possible. The authors also thank the At Home/Chez Soi project team, site coordinators, and service providers for their tireless contributions to the study design, implementation, and follow-up. Finally, the authors acknowledge Rick Wang for his kind support with data set preparation.
      All authors contributed to the design of the study. ML, SWH, CML, and JL conceived of the study. ML performed the analysis, interpreted the results, and prepared the first manuscript draft. CML and JL provided guidance on the analysis and structuring of the first manuscript draft. SWH, CML, JL, RN, and VS critically reviewed the manuscript. All authors contributed to and approved the final manuscript.
      This study was supported by financial contributions from the Mental Health Commission of Canada, Ontario Ministry of Health and Long-Term Care ( HSRF #259 ), and the Canadian Institutes of Health Research ( CIHR MOP-130405 ). The funding institutions had no role in the collection, analysis, and interpretation of the data, nor in the preparation, revision, or approval of the present manuscript. The views expressed in this publication are solely those of the authors.
      No financial disclosures were reported by the authors of this paper.

      Appendix. SUPPLEMENTAL MATERIAL

      REFERENCES

        • Corso PS
        • Edwards VJ
        • Fang X
        • Mercy JA
        Health-related quality of life among adults who experienced maltreatment during childhood.
        Am J Public Health. 2008; 98: 1094-1100
        • Anda RF
        • Felitti VJ
        • Bremner JD
        • et al.
        The enduring effects of abuse and related adverse experiences in childhood: a convergence of evidence from neurobiology and epidemiology.
        Eur Arch Psychiatry Clin Neurosci. 2006; 256: 174-186
        • Dube SR
        • Anda RF
        • Felitti VJ
        • Chapman DP
        • Williamson DF
        • Giles WH
        Childhood abuse, household dysfunction, and the risk of attempted suicide throughout the life span: findings from the Adverse Childhood Experiences study.
        JAMA. 2001; 286: 3089-3096
        • Felitti VJ
        • Anda RF
        • Nordenberg D
        • et al.
        Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. The Adverse Childhood Experiences (ACE) Study.
        Am J Prev Med. 1998; 14: 245-258
        • Schilling EA
        • Aseltine RH
        • Gore S
        Adverse childhood experiences and mental health in young adults: a longitudinal survey.
        BMC Public Health. 2007; 7: 30
        • Chapman DP
        • Whitfield CL
        • Felitti VJ
        • Dube SR
        • Edwards VJ
        • Anda RF
        Adverse childhood experiences and the risk of depressive disorders in adulthood.
        J Affect Disord. 2004; 82: 217-225
        • Horwitz AV
        • Widom CS
        • McLaughlin J
        • White HR
        The impact of childhood abuse and neglect on adult mental health: a prospective study.
        J Health Soc Behav. 2001; 42: 184-201
        • Green JG
        • McLaughlin KA
        • Berglund PA
        • et al.
        Childhood adversities and adult psychiatric disorders in the national comorbidity survey replication I: associations with first onset of DSM-IV disorders.
        Arch Gen Psychiatry. 2010; 67: 113-123
        • Bellis MA
        • Hughes K
        • Ford K
        • Ramos Rodriguez G
        • Sethi D
        • Passmore J
        Life course health consequences and associated annual costs of adverse childhood experiences across Europe and North America: a systematic review and meta-analysis.
        Lancet Public Health. 2019; 4: e517-e528
        • Hughes K
        • Bellis MA
        • Hardcastle KA
        • et al.
        The effect of multiple adverse childhood experiences on health: a systematic review and meta-analysis.
        Lancet Public Health. 2017; 2: e356-e366
        • Dube SR
        • Williamson DF
        • Thompson T
        • Felitti VJ
        • Anda RF
        Assessing the reliability of retrospective reports of adverse childhood experiences among adult HMO members attending a primary care clinic.
        Child Abuse Negl. 2004; 28: 729-737
        • Roos LE
        • Mota N
        • Afifi TO
        • Katz LY
        • Distasio J
        • Sareen J
        Relationship between adverse childhood experiences and homelessness and theimpact of Axis I and II disorders.
        Am J Public Health. 2013; 103: S275-S281
        • Lee CM
        • Mangurian C
        • Tieu L
        • Ponath C
        • Guzman D
        • Kushel M
        Childhood adversities associated with poor adult mental health outcomes in older homeless adults: results from the HOPE HOME Study.
        Am J Geriatr Psychiatry. 2017; 25: 107-117
        • Brown RT
        • Goodman L
        • Guzman D
        • Tieu L
        • Ponath C
        • Kushel MB
        Pathways to homelessness among older homeless adults: results from the HOPE HOME study.
        PLoS One. 2016; 11e0155065
        • Stein JA
        • Leslie MB
        • Nyamathi A
        Relative contributions of parent substance use and childhood maltreatment to chronic homelessness, depression, and substance abuse problems among homeless women: mediating roles of self-esteem and abuse in adulthood.
        Child Abus Negl. 2002; 26: 1011-1027
        • Torchalla I
        • Strehlau V
        • Li K
        • Schuetz C
        • Krausz M
        The association between childhood maltreatment subtypes and current suicide risk among homeless men and women.
        Child Maltreat. 2012; 17: 132-143
        • Tam TW
        • Zlotnick C
        • Robertson MJ
        Longitudinal perspective: adverse childhood events, substance use, and labor force participation among homeless adults.
        Am J Drug Alcohol Abuse. 2003; 29: 829-846
        • Patterson ML
        • Moniruzzaman A
        • Somers JM
        Setting the stage for chronic health problems: cumulative childhood adversity among homeless adults with mental illness in Vancouver, British Columbia.
        in: Albers Prock L Childhood Adversity and Developmental Effects: International and Cross-Disciplinary Perspectives. Apple Academic Press, New York, NY2015: 41-62
        • Masten AS
        Ordinary magic: resilience processes in development.
        Ann Psychol. 2001; 56: 227-238
        • Masten AS
        • Best KM
        • Garmezy N
        Resilience and development: contributions from the study of children who overcome adversity.
        Dev Psychopathol. 1990; 2: 425-444
        • Bonnano GA
        Loss, trauma, and human resilience. Have we underestimated the human capacity to thrive after extremely aversive events?.
        Ann Psychol. 2009; 59: 20-28
        • Kim-Cohen J
        Resilience and developmental psychopathology.
        Child Adolesc Psychiatr Clin N Am. 2007; 16: 271-283
        • Sameroff AJ
        Developmental systems and psychopathology.
        Dev Psychopathol. 2000; 12: 297-312
        • Goering PN
        • Streiner DL
        • Adair C
        • et al.
        The At Home/Chez Soi trial protocol: a pragmatic, multi-site, randomised controlled trial of a Housing first intervention for homeless individuals with mental illness in five Canadian cities.
        BMJ Open. 2011; 1e000323
        • Hwang SW
        • Stergiopoulos V
        • O'Campo P
        • Gozdzik A
        Ending homelessness among people with mental illness: the At Home/Chez Soi randomized trial of a Housing first intervention in Toronto.
        BMC Public Health. 2012; 12: 787
        • Sheehan DV
        • Lecrubier Y
        • Sheehan KH
        • et al.
        The Mini-International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10.
        J Clin Psychiatry. 1998; 59: 22-33
        • Andersen JP
        • Blosnich J
        Disparities in adverse childhood experiences among sexual minority and heterosexual adults: results from a multi-state probability-based sample.
        PLoS One. 2013; 8: e54691
        • Schneeberger AR
        • Dietl MF
        • Muenzenmaier KH
        • Huber CG
        • Lang UE
        Stressful childhood experiences and health outcomes in sexual minority populations: a systematic review.
        Soc Psychiatry Psychiatr Epidemiol. 2014; 49: 1427-1445
        • Mustanski B
        • Andrews R
        • Puckett JA
        The effects of cumulative victimization on mental health among lesbian, gay, bisexual, and transgender adolescents and young adults.
        Am J Public Health. 2016; 106: 527-533
        • Reuben A
        • Moffitt TE
        • Caspi A
        • et al.
        Lest we forget: comparing retrospective and prospective assessments of adverse childhood experiences in the prediction of adult health.
        J Child Psychol Psychiatry. 2016; 57: 1103-1112
        • Vaishnavi S
        • Connor K
        • Davidson JRT
        An abbreviated version of the Connor-Davidson Resilience Scale (CD-RISC), the CD-RISC2: psychometric properties and applications in psychopharmacological trials.
        Psychiatry Res. 2007; 152: 293-297
        • Connor KM
        • Davidson JRT
        Development of a new resilience scale: the Connor-Davidson Resilience scale (CD-RISC).
        Depress Anxiety. 2003; 18: 76-82
        • Conrad KJ
        • Yagelka JR
        • Matters MD
        • Rich AR
        • Williams V
        • Buchanan M
        Reliability and validity of a modified Colorado Symptom Index in a national homeless sample.
        Ment Health Serv Res. 2001; 3: 141-153
        • Boothroyd RA
        • Chen HJ
        The psychometric properties of the Colorado Symptom Index.
        Admin Policy Ment Health. 2008; 35: 370-378
        • Edwards VJ
        • Anda RF
        • Nordenberg DF
        • Felitti VJ
        • Williamson DF
        • Wright JA
        Bias assessment for child abuse survey: factors affecting probability of response to a survey about childhood abuse.
        Child Abuse Negl. 2001; 25: 307-312
        • Herman DB
        • Susser ES
        • Struening EL
        • Link BL
        Adverse childhood experiences: are they risk factors for adult homelessness?.
        Am J Public Health. 1997; 87: 249-255
        • Graham JW
        • Olchowski AE
        • Gilreath TD
        How many imputations are really needed? Some practical clarifications of multiple imputation theory.
        Prev Sci. 2007; 8: 206-213
        • Royston P
        • White I
        Multiple Imputation by Chained Equations (MICE): implementation in Stata.
        J Stat Soft. 2015; 45: 1-20
        • Azur MJ
        • Stuart EA
        • Frangakis C
        • Leaf PJ
        Multiple imputation by chained equations: what is it and how does it work?.
        Int J Methods Psychiatr Res. 2011; 20: 40-49
        • Sterne JAC
        • White IR
        • Carlin JB
        • et al.
        Multiple imputation for missing data in epidemiological and clinical research: potential and pitfalls.
        BMJ. 2009; 338: b2393
        • Eddings W
        • Marchenko Y
        Diagnostics for multiple imputation in Stata.
        Stata J. 2012; 12: 353-367
        • Rothman KJ
        No adjustments are needed for multiple comparisons.
        Epidemiology. 1990; 1: 43-46
        • Streiner DL
        • Norman GR
        Correction for multiple testing: is there a resolution?.
        Chest. 2011; 140: 16-18
        • Armstrong RA
        When to use the Bonferroni correction.
        Ophthal Physiol Opt. 2014; 34: 502-508
        • Harrington D
        • D'Agostino RB
        • Gatsonis C
        • et al.
        New guidelines for statistical reporting in the journal.
        N Engl J Med. 2019; 381: 285-286
        • Lee JS
        • Ahn YS
        • Jeong KS
        • Chae JH
        • Choi KS
        Resilience buffers the impact of traumatic events on the development of PTSD symptoms in firefighters.
        J Affect Disord. 2014; 162: 128-133
        • Cheong EV
        • Sinnott C
        • Dahly D
        • Kearney PM
        Adverse childhood experiences (ACEs) and later-life depression: perceived social support as a potential protective factor.
        BMJ Open. 2017; 7e013228
        • Cameron CA
        • Ungar M
        • Liebenberg L
        Cultural understandings of resilience: roots for wings in the development of affective resources for resilience.
        Child Adolesc Psychiatr Clin N Am. 2007; 16: 285-301
        • Davydov DM
        • Stewart R
        • Ritchie K
        • Chaudieu I
        Resilience and mental health.
        Clin Psychol Rev. 2010; 30: 479-495
        • Lee JS
        Perceived social support functions as a resilience in buffering the impact of trauma exposure on PTSD symptoms via intrusive rumination and entrapment in firefighters.
        PLoS One. 2019; 14e0220454
        • Luthar SS
        • Cicchetti D
        • Becker B
        The construct of resilience: a critical evaluation and guidelines for future work.
        Child Dev. 2000; 71: 543-562
        • Masten AS
        • Hubbard JJ
        • Gest SD
        • Tellegen A
        • Garmezy N
        • Ramirez M
        Competence in the context of adversity: pathways to resilience and maladaptation from childhood to late adolescence.
        Dev Psychopathol. 1999; 11: 143-169
        • Egeland B
        • Carlson E
        • Sroufe LA
        Resilience as process.
        Dev Psychopathol. 1993; 5: 517-528
        • Copeland WE
        • Keeler G
        • Angold A
        • Costello EJ
        Traumatic events and posttraumatic stress in childhood.
        Arch Gen Psychiatry. 2007; 64: 577-584
        • Kessler RC
        • Davis CG
        • Kendler KS
        Childhood adversity and adult psychiatric disorder in the U.S. National Comorbidity Survey.
        Psychol Med. 1997; 27: 1101-1119
        • Hasin DS
        • O'Brien CP
        • Auriacombe M
        • et al.
        DSM-5 criteria for substance use disorders: recommendations and rationale.
        Am J Psychiatry. 2013; 170: 834-851
        • Hays SP
        • Hays CE
        • Mulhall PF
        Community risk and protective factors and adolescent substance use.
        J Prim Prev. 2003; 24: 125-142
        • Sinha R
        Chronic stress, drug use, and vulnerability to addiction.
        Ann N Y Acad Sci. 2008; 1141: 105-130
        • Chen X
        • Tyler KA
        • Whitbeck LB
        • Hoyt DR
        Early sexual abuse, street adversity, and drug use among female homeless and runaway adolescents in the Midwest.
        J Drug Issues. 2004; 34: 1-21
        • Read J
        • Van Os J
        • Morrison AP
        • Ross CA
        Childhood trauma, psychosis and schizophrenia: a literature review with theoretical and clinical implications.
        Acta Psychiatr Scand. 2005; 112: 330-350
        • Varese F
        • Smeets F
        • Drukker M
        • et al.
        Childhood adversities increase the risk of psychosis: a meta-analysis of patient-control, prospective- and cross-sectional cohort studies.
        Schizophr Bull. 2012; 38: 661-671
        • Janssen I
        • Krabbendam L
        • Bak M
        • et al.
        Childhood abuse as a risk factor for psychotic experiences.
        Acta Psychiatr Scand. 2004; 109: 38-45
        • Bendall S
        • Jackson HJ
        • Hulbert CA
        • McGorry PD
        Childhood trauma and psychotic disorders: a systematic, critical review of the evidence.
        Schizophr Bull. 2008; 34: 568-579
        • Lysaker PH
        • Beattie NL
        • Strasburger AM
        • Davis LW
        Reported history of child sexual abuse in schizophrenia: associations with heightened symptom levels and poorer participation over four months in vocational rehabilitation.
        J Nerv Ment Dis. 2005; 193: 790-795
        • Deng M
        • Pan Y
        • Zhou L
        • et al.
        Resilience and cognitive function in patients with schizophrenia and bipolar disorder, and healthy controls.
        Front Psychiatry. 2018; 9: 279
        • Browne A
        • Finkelhor D
        Impact of child sexual abuse. a review of the research.
        Psychol Bull. 1986; 99: 66-77
        • Macedo T
        • Wilheim L
        • Gonçalves R
        • et al.
        Building resilience for future adversity: a systematic review of interventions in non-clinical samples of adults.
        BMC Psychiatry. 2014; 14: 227
        • Greenberg MT
        Promoting resilience in children and youth: preventive interventions and their interface with neuroscience.
        Ann N Y Acad Sci. 2006; 1094: 139-150
        • Galante J
        • Dufour G
        • Vainre M
        • et al.
        A mindfulness-based intervention to increase resilience to stress in university students (the Mindful Student Study): a pragmatic randomised controlled trial.
        Lancet Public Health. 2018; 3: e72-e81
        • Gillham JE
        • Reivich KJ
        • Freres DR
        • et al.
        School-based prevention of depressive symptoms: a randomized controlled study of the effectiveness and specificity of the Penn Resiliency Program.
        J Consult Clin Psychol. 2007; 75: 9-19
        • Fava GA
        • Tomba E
        Increasing psychological well-being and resilience by psychotherapeutic methods.
        J Pers. 2009; 77: 1903-1934
        • Durbin A
        • Nisenbaum R
        • Kopp B
        • O'Campo P
        • Hwang SW
        • Stergiopoulos V
        Are resilience and perceived stress related to social support and housing stability among homeless adults with mental illness?.
        Health Soc Care Commun. 2019; 27: 1053-1062
        • Paul S
        • Corneau S
        • Boozary T
        • Stergiopoulos V
        Coping and resilience among ethnoracial individuals experiencing homelessness and mental illness.
        Int J Soc Psychiatry. 2018; 64: 189-197
        • Garner AS
        • Shonkoff JP
        • Committee on Psychosocial Aspects of Child and Family Health, Committee on Early Childhood, Adoption, and Dependent Care, Section on Developmental and Behavioral Pediatrics
        Early childhood adversity, toxic stress, and the role of the pediatrician: translating developmental science into lifelong health.
        Pediatrics. 2012; 129: e224-e231
        • Dawson G
        • Ashman SB
        • Carver LJ
        The role of early experience in shaping behavioral and brain development and its implications for social policy.
        Dev Psychopathol. 2000; 12: 695-712
        • Mullen PE
        • Martin JL
        • Anderson JC
        • Romans SE
        • Herbison GP
        The long-term impact of the physical, emotional, and sexual abuse of children: a community study.
        Child Abuse Negl. 1996; 20: 7-21
        • Callaghan BL
        • Tottenham N
        The stress acceleration hypothesis: effects of early-life adversity on emotion circuits and behavior.
        Curr Opin Behav Sci. 2016; 7: 76-81
        • Olds D
        • Henderson CR
        • Cole R
        • et al.
        Long-term effects of nurse home visitation on children's criminal and antisocial behavior: 15-year follow-up of a randomized controlled trial.
        JAMA. 1998; 280: 1238-1244
        • Prinz RJ
        • Sanders MR
        • Shapiro CJ
        • Whitaker DJ
        • Lutzker JR
        Population-based prevention of child maltreatment: the U.S. Triple P System Population Trial.
        Prev Sci. 2009; 10: 1-12
        • Cohen JA
        • Mannarino AP
        Trauma-focused cognitive behavioural therapy for children and parents.
        Child Adolesc Ment Health. 2008; 13: 158-162
        • Coulter S
        Systemic family therapy for families who have experienced trauma: a randomised controlled trial.
        Br J Soc Work. 2011; 41: 502-519
        • Cohen JA
        • Deblinger E
        • Mannarino AP
        • Steer RA
        A multisite, randomized controlled trial for children with sexual abuse-related PTSD symptoms.
        J Am Acad Child Adolesc Psychiatry. 2004; 43: 393-402
        • Briere J
        • Scott C
        Complex trauma in adolescents and adults: effects and treatment.
        Psychiatr Clin North Am. 2015; 38: 515-527
        • Logan-Greene P
        • Green S
        • Nurius PS
        • Longhi D
        Distinct contributions of adverse childhood experiences and resilience resources: a cohort analysis of adult physical and mental health.
        Soc Work Health Care. 2014; 53: 776-797
        • Turner HA
        • Butler MJ
        Direct and indirect effects of childhood adversity on depressive symptoms in young adults.
        J Youth Adolesc. 2003; 32: 89-103
        • Fazel S
        • Khosla V
        • Doll H
        • Geddes J
        The prevalence of mental disorders among the homeless in Western countries: systematic review and meta-regression analysis.
        PLoS Med. 2008; 5: e225
        • Afifi TO
        • Mather A
        • Boman J
        • et al.
        Childhood adversity and personality disorders: results from a nationally representative population-based study.
        J Psychiatr Res. 2011; 45: 814-822
        • Pettersson A
        • Modin S
        • Wahlström R
        • Af Winklerfelt Hammarberg S
        • Krakau I
        The Mini-International Neuropsychiatric Interview is useful and well accepted as part of the clinical assessment for depression and anxiety in primary care: a mixed-methods study.
        BMC Fam Pract. 2018; 19: 19
        • Maughan B
        • Rutter M
        Retrospective reporting of childhood adversity: issues in assessing long-term recall.
        J Pers Disord. 1997; 11: 19-33
        • Kang H
        The prevention and handling of the missing data.
        Korean J Anesthesiol. 2013; 64: 402-406