Shelter Bans Among People Experiencing Homelessness: an Exploratory Study of Predictors in Two Large Canadian Datasets.

Emergency shelters are a core component of homeless service systems that address immediate basic needs. Service bans, which refer to temporary or permanent disallowances from a program or organization, are an underresearched phenomenon that can leave people experiencing homelessness without needed supports. This exploratory study examined the factors associated with shelter bans among people experiencing homelessness using secondary data from two Canadian studies: (1) a multisite randomized controlled trial of Housing First (At Home/Chez Soi Demonstration Project) and (2) a cross-sectional survey of youth experiencing homelessness across Canada (2019 Without a Home-National Youth Homelessness Survey). The two datasets were analyzed separately using logistic regression models with similar predictors to maximize the comparability of the results. Participants who experienced homelessness at an earlier age and had recent criminal justice system involvement were more likely to have shelter bans in both datasets. Impaired impulse control, more chronic medical conditions and living in Toronto were associated with increased likelihood of shelter bans in the At Home/Chez Soi dataset, whereas more adverse childhood experiences, physical violence victimization, engagement in survival sex behaviours and longer current episodes of homelessness were significant predictors of bans in the Without A Home dataset. Overall, the findings suggest that victimization and criminalization during homelessness may increase the risk of shelter loss from bans and further exclusion. The observed regional differences also highlight the potential limits of individual-level predictors. Further research is needed on shelter ban outcomes, as well as how capacity limits and organizational policies affect banning decisions.

Overall and Gender-specific Associations between Dimensions of Adverse Childhood Experiences and Mental Health Outcomes among Homeless Adults: Associations Générales et Sexospécifiques Entre les Dimensions des Expériences Défavorables de L'enfance et les Résultats de Santé Mentale Chez les Adultes Sans Abri.

OBJECTIVE: The associations between adverse childhood experiences (ACEs) and psychopathology have been well-established in the general population. Research on ACEs in the homeless population has been limited. This study examined whether ACE exposure is associated with specific mental health outcomes among a national sample of homeless adults with mental illness and whether this association varies according to ACE dimension and gender. METHODS: This cross-sectional study utilized data from a national sample of 2,235 homeless adults with mental illness in Canada to evaluate their sociodemographic characteristics, exposure to ACEs, and mental health outcomes. Exploratory and confirmatory factor analyses were conducted to identify and confirm ACE dimensions (maltreatment, sexual abuse, neglect, divorce, and household dysfunction) from individual ACE items. Multivariable logistic regression was used to examine the associations between total ACE score and ACE dimensions with mental illness diagnoses and psychopathology severity. RESULTS: The mean total ACE score among all study participants was 4.44 (standard deviation [SD]: 2.99). Total ACE score was positively associated with several mental illness diagnoses and psychopathology severity. Unique associations were found between specific ACE dimensions and poor mental health outcomes. The prevalence of almost all ACEs was significantly higher among women. Yet, associations between several ACE dimensions and poor mental health outcomes existed uniquely among men. CONCLUSIONS: There are unique and gender-specific associations between specific ACE dimensions and mental health outcomes among homeless adults. Better understanding of the mechanisms underlying these associations is needed to inform screening, prevention, and treatment efforts, particularly given the very high prevalence of ACEs among this vulnerable and marginalized population.

Examining the Relationships between Cumulative Childhood Adversity and the Risk of Criminal Justice Involvement and Victimization among Homeless Adults with Mental Illnesses after Receiving Housing First Intervention.

OBJECTIVES: Exposure to adverse childhood experiences (ACEs) is associated with increased risk of criminal justice involvement and repeated victimization among homeless individuals. This study aimed to (1) examine whether the relationship between cumulative ACE score and odds of experiencing criminal justice involvement and victimization remains significant over time after receiving the Housing First (HF) intervention and (2) investigate the moderating effect of cumulative ACE score on the effectiveness of the HF intervention on the likelihood of experiencing these outcomes among homeless individuals with mental illnesses. METHODS: We used longitudinal data over the 2-year follow-up period from the At Home/Chez Soi demonstration project that provided HF versus treatment as usual (TAU) to homeless adults with mental illness in five Canadian cities (N = 1,888). RESULTS: In all 4 follow-up time points, the relationship between cumulative ACE score and both outcomes remained significant, regardless of study arm (HF vs. TAU) and other confounding factors. However, cumulative ACE score did not moderate intervention effects on odds of experiencing either outcome, suggesting that the effectiveness of HF versus TAU, with regard to the odds of being victimized or criminal justice involvement, did not differ by cumulative ACE scores over the course of study. CONCLUSIONS: Findings suggest that providing services for homeless individuals with mental illness should be trauma informed and include specialized treatment strategies targeting the experience of ACEs and trauma to improve their treatment outcomes. An intensive approach is required to directly address the problem of criminal justice involvement and victimization in these individuals.

Fixed Nodes of Transience: Narratives of Homelessness and Emergency Department Use.

Discourse in popular media, public policy, and academic literature contends that people who are homeless frequently make inappropriate use of hospital emergency department (ED) services. Although researchers have investigated the ED experiences of people who are homeless, no previous studies have examined how this population understands the role of the ED in their health care and in their day-to-day lives. In the present study, 16 individuals participated in semistructured interviews regarding their ED experiences, and narrative analysis was applied to their responses. Within the context of narratives of disempowerment and discrimination, participants viewed the ED in differing ways, but they generally interpreted it as a public, accessible space where they could exert agency. ED narratives were also paradoxical, depicting it as a fixed place for transient care, or a place where they were isolated yet felt a sense of belonging. Implications for policy and practice are discussed.

Indigenous and non-Indigenous parents separated from their children and experiencing homelessness and mental illness in Canada.

The purpose of this study is to examine the parent-child experiences of Indigenous and non-Indigenous mothers and fathers experiencing homelessness, mental illness, and separation from their children. A qualitative thematic analysis of baseline and 18-month follow-up narrative interviews was used to compare 12 mothers (n = 8 Indigenous and n = 4 nonindigenous) with 24 fathers (n = 13 Indigenous and n = 11 non-Indigenous). First, it was found that children are more central in the lives of mothers than fathers. Second, Indigenous parents' narratives were characterized by interpersonal and systemic violence, racism and trauma, and cultural disconnection, but also more cultural healing resources. Third, an intersectional analysis showed that children were peripheral in the lives of non-Indigenous fathers, and most central to the identities of Indigenous mothers. Gender identity, Indigenous, and intersectional theories are used to interpret the findings. Implications for future theory, research, and culturally relevant intervention are discussed.

Effectiveness of Housing First for Homeless Adults with Mental Illness Who Frequently Use Emergency Departments in a Multisite Randomized Controlled Trial.

Frequent emergency department (ED) users experiencing homelessness are associated with high costs for healthcare systems yet interventions for this group have been minimally investigated. This study used 24-month data from a multisite randomized controlled trial of Housing First (HF) to examine how effective the intervention is in helping frequent ED users with a mental illness to achieve housing stability, improve behavioural health and functioning, and reduce their ED use. Findings showed that HF is effective in stably housing frequent ED users despite their complex health needs. Reductions in ED use and substance use problems, and improvements in mental health symptoms and community functioning were found for frequent ED users in both the HF and treatment as usual conditions.

Predictors of Mental Health Recovery in Homeless Adults with Mental Illness.

For people with mental illness, experiences of homelessness can complicate mental health recovery processes. This study used longitudinal data from a randomized controlled trial of housing first (HF) to examine predictors of recovery among homeless people with mental illness. Findings showed that health and community predictors were most strongly associated with mental health recovery. Receipt of HF did not have any effect on changes in recovery scores at follow-up. Overall, the findings suggest that interventions aimed at preventing chronic homelessness, strengthening social networks and community involvement, and providing case management services will facilitate mental health recovery.

The entrepreneurship of survival among urban adults experiencing homelessness and mental illness.

AIMS: Using an entrepreneurship lens, this study examined the narratives of urban adults experiencing homelessness and living with mental illness, to explore strategies used for day-to-day survival. METHODS: Semi-structured qualitative interviews were conducted with 14 females, 30 males, and one individual identifying as "other," living in a mid-sized Canadian city. The average age was 39 years. Data were transcribed verbatim and analyzed using thematic analysis informed by grounded theory. FINDINGS: Participants described creative and intentional strategies for managing life on the street without permanent shelter, including recognition of opportunities, mobilization of their own or acquired resources, and use of social connections and communication skills, and strategies that demonstrated entrepreneurial processes. CONCLUSIONS: Findings suggest that participants used survival entrepreneurship strategies and processes to navigate daily life while experiencing homelessness. Recognition and validation of the propensity for enterprise and self-sufficiency are central for both individual recovery and ending homelessness within similar populations.

Systems change in the context of an initiative to scale up Housing First in Canada.

In this study, we examine changes in the homeless-serving system in the context of a training and technical assistance initiative to scale up Housing First (HF) in 6 Canadian communities. Based on qualitative data from focus groups and individual interviews with key stakeholders (k = 7, n = 35) and field notes gathered over a 3-year period (n = 146), we found 2 main system changes: (a) changes in the capacity of the service delivery system at multiple levels of analysis (from individual to policy) to implement HF, and (b) changes in the coordination of parts of the service delivery system and collaboration among local stakeholders to enhance HF implementation. These changes were facilitated or constrained by the larger context of evidence, climate, policy, and funding. The findings were discussed in terms of systems change theory and implications for transformative systems change in the mental health and homelessness sectors.

The effects of housing stability on service use among homeless adults with mental illness in a randomized controlled trial of housing first.

BACKGROUND: Housing First is an effective intervention to stably house and alter service use patterns in a large proportion of homeless people with mental illness. However, it is unknown whether there are differences in the patterns of service use over time among those who do or do not become stably housed and what effect, if any, Housing First has on these differing service use patterns. This study explored changes in the service use of people with mental illness who received Housing First compared to standard care, and how patterns of use differed among people who did and did not become stably housed. METHODS: The study design was a multi-site randomized controlled trial of Housing First, a supported housing intervention. 2039 participants (Housing First: n = 1131; standard care: n = 908) were included in this study. Outcome variables include nine types of self-reported service use over 24 months. Linear mixed models examined what effects the intervention and housing stability had on service use. RESULTS: Participants who achieved housing stability, across the two groups, had decreased use of inpatient psychiatric hospitals and increased use of food banks. Within the Housing First group, unstably housed participants spent more time in prison over the study period. The Housing First and standard care groups both had decreased use of emergency departments and homeless shelters. CONCLUSIONS: The temporal service use changes that occurred as homeless people with mental illness became stably housed are similar for those receiving Housing First or standard care, with the exception of time in prison. Service use patterns, particularly with regard to psychiatric hospitalizations and time in prison, may signify persons who are at-risk of recurrent homelessness. Housing support teams should be alert to the impacts of stay-based services, such as hospitalizations and incarcerations, on housing stability and offer an increased level of support to tenants during critical periods, such as discharges. TRIAL REGISTRATION: ISRCTN. ISRCTN42520374 . Registered 18 August 2009.

Changes in healthcare use among individuals who move into public housing: a population-based investigation.

BACKGROUND: Residence in public housing, a subsidized and managed government program, may affect health and healthcare utilization. We compared healthcare use in the year before individuals moved into public housing with usage during their first year of tenancy. We also described trends in use. METHODS: We used linked population-based administrative data housed in the Population Research Data Repository at the Manitoba Centre for Health Policy. The cohort consisted of individuals who moved into public housing in 2009 and 2010. We counted the number of hospitalizations, general practitioner (GP) visits, specialist visits, emergency department visits, and prescriptions drugs dispensed in the twelve 30-day intervals (i.e., months) immediately preceding and following the public housing move-in date. Generalized linear models with generalized estimating equations tested for a period (pre/post-move-in) by month interaction. Odds ratios (ORs), incident rate ratios (IRRs), and means are reported along with 95% confidence intervals (95% CIs). RESULTS: The cohort included 1942 individuals; the majority were female (73.4%) who lived in low income areas and received government assistance (68.1%). On average, the cohort had more than four health conditions. Over the 24 30-day intervals, the percentage of the cohort that visited a GP, specialist, and an emergency department ranged between 37.0% and 43.0%, 10.0% and 14.0%, and 6.0% and 10.0%, respectively, while the percentage of the cohort hospitalized ranged from 1.0% to 5.0%. Generally, these percentages were highest in the few months before the move-in date and lowest in the few months after the move-in date. The period by month interaction was statistically significant for hospitalizations, GP visits, and prescription drug use. The average change in the odds, rate, or mean was smaller in the post-move-in period than in the pre-move-in period. CONCLUSIONS: Use of some healthcare services declined after people moved into public housing; however, the decrease was only observed in the first few months and utilization rebounded. Knowledge of healthcare trends before individuals move in are informative for ensuring the appropriate supports are available to new public housing residents. Further study is needed to determine if decreased healthcare utilization following a move is attributable to decreased access.

Navigating Complex Implementation Contexts: Overcoming Barriers and Achieving Outcomes in a National Initiative to Scale Out Housing First in Canada.

The scaling out of Housing First (HF) programs was examined in six Canadian communities, in which a multi-component HF training and technical assistance (TTA) was provided. Three research questions were addressed: (a) What were the outcomes of the TTA in terms of the development of new, sustained, or enhanced programs, and fidelity to the HF model? (b) How did the TTA contribute to implementation and fidelity? and (c) What contextual factors facilitated or challenged implementation and fidelity? A total of 14 new HF programs were created, and nine HF programs were sustained or enhanced. Fidelity assessments for 10 HF programs revealed an average score of 3.3/4, which compares favorably with other HF programs during early implementation. The TTA influenced fidelity by addressing misconceptions about the model, encouraging team-based practice, and facilitating case-based dialogue on site specific implementation challenges. The findings were discussed in terms of the importance of TTA for enhancing the capacities of the HF service delivery system-practitioners, teams, and communities-while respecting complex community contexts, including differences in policy climate across sites. Policy climate surrounding accessibility of housing subsidies, and use of Assertive Community Treatment teams (vs. Intensive Case Management) were two key implementation issues.

Understanding Systems Change in Early Implementation of Housing First in Canadian Communities: An Examination of Facilitators/Barriers, Training/Technical Assistance, and Points of Leverage.

We present interim findings of a cross-site case study of an initiative to expand Housing First (HF) in Canada through training and technical assistance (TTA). HF is an evidence-based practice designed to end chronic homelessness for consumers of mental health services. We draw upon concepts from implementation science and systems change theory to examine how early implementation occurs within a system. Case studies examining HF early implementation were conducted in six Canadian communities receiving HF TTA. The primary data are field notes gathered over 1.5 years and evaluations from site-specific training events (k = 5, n = 302) and regional network training events (k = 4, n = 276). We report findings related to: (a) the facilitators of and barriers to early implementation, (b) the influence of TTA on early implementation, and (c) the "levers" used to facilitate broader systems change. Systems change theory enabled us to understand how various "levers" created opportunities for change within the communities, including establishing system boundaries, understanding how systems components can function as causes of or solutions to a problem, and assessing and changing systems interactions. We conclude by arguing that systems theory adds value to existing implementation science frameworks and can be helpful in future research on the implementation of evidence-based practices such as HF which is a complex community intervention. Implications for community psychology are discussed.

Food security among individuals experiencing homelessness and mental illness in the At Home/Chez Soi Trial.

OBJECTIVE: Individuals experiencing homelessness are particularly vulnerable to food insecurity. The At Home/Chez Soi study provides a unique opportunity to first examine baseline levels of food security among homeless individuals with mental illness and second to evaluate the effect of a Housing First (HF) intervention on food security in this population. DESIGN: At Home/Chez Soi was a 2-year randomized controlled trial comparing the effectiveness of HF compared with usual care among homeless adults with mental illness, stratified by level of need for mental health services (high or moderate). Logistic regressions tested baseline associations between food security (US Food Security Survey Module), study site, sociodemographic variables, duration of homelessness, alcohol/substance use, physical health and service utilization. Negative binomial regression determined the impact of the HF intervention on achieving levels of high or marginal food security over an 18-month follow-up period (6 to 24 months). SETTING: Community settings at five Canadian sites (Moncton, Montreal, Toronto, Winnipeg and Vancouver). SUBJECTS: Homeless adults with mental illness (n 2148). RESULTS: Approximately 41 % of our sample reported high or marginal food security at baseline, but this figure varied with gender, age, mental health issues and substance use problems. High need participants who received HF were more likely to achieve marginal or high food security than those receiving usual care, but only at the Toronto and Moncton sites. CONCLUSIONS: Our large multi-site study demonstrated low levels of food security among homeless experiencing mental illness. HF showed promise for improving food security among participants with high levels of need for mental health services, with notable site differences.

Effect of Housing First on Suicidal Behaviour: A Randomised Controlled Trial of Homeless Adults with Mental Disorders.

OBJECTIVE: This study attempted to determine if Housing First (HF) decreased suicidal ideation and attempts compared to treatment as usual (TAU) amongst homeless persons with mental disorders, a population with a demonstrably high risk of suicidal behaviour. METHOD: The At Home/Chez Soi project is an unblinded, randomised control trial conducted across 5 Canadian cities (Vancouver, Winnipeg, Toronto, Montreal, Moncton) from 2009 to 2013. Homeless adults with a diagnosed major mental health disorder were recruited through community agencies and randomised to HF ( n = 1265) and TAU ( n = 990). HF participants were provided with private housing units and received case management support services. TAU participants retained access to existing community supports. Past-month suicidal ideation was measured at baseline and 6, 12, 18, and 21/24 months. A history of suicide attempts was measured at baseline and the 21/24-month follow-up. RESULTS: Compared to baseline, there was an overall trend of decreased past-month suicidal ideation (estimate = -.57, SE = .05, P < 0.001), with no effect of treatment group (i.e., HF vs. TAU; estimate = -.04, SE = .06, P = 0.51). Furthermore, there was no effect of treatment status (estimate = -.10, SE = .16, P = 0.52) on prevalence of suicide attempts (HF = 11.9%, TAU = 10.5%) during the 2-year follow-up period. CONCLUSION: This study failed to find evidence that HF is superior to TAU in reducing suicidal ideation and attempts. We suggest that HF interventions consider supplemental psychological treatments that have proven efficacy in reducing suicidal behaviour. It remains to be determined what kind of suicide prevention interventions (if any) are specifically effective in further reducing suicidal risk in a housing-first intervention.

Housing Quality in a Randomized Controlled Trial of Housing First for Homeless Individuals with Mental Illness: Correlates and Associations with Outcomes.

Housing quality (HQ) is associated with mental health, and may mediate outcomes in housing interventions. However, studies of housing interventions rarely report HQ. The purpose of this study was to describe HQ in a multi-site randomized controlled trial of Housing First (HF) in five Canadian cities and to examine possible differences by treatment group (HF recipients and treatment-as-usual (TAU) participants who were able to find housing through other programs or on their own). We also examined the association between HQ and the primary trial outcome: housing stability. The performance of a new multi-dimensional standardized observer-rated housing quality scale (the OHQS) in a relatively large cross-site sample was also of interest. HQ was rated by trained research assistants for 204 HF participants and 228 TAU participants using the OHQS. General linear regression models were used to examine unit/building quality scores by group and site adjusting for other group differences, and as a predictor of housing stability outcomes after 24 months of follow-up. The OHQS was found to have good reliability and validity, but because most of the neighborhood subscale items were negatively correlated with the overall scale, only unit and building items were included in the total HQ score (possible scores ranging from 13.5 to 135). Unit/building HQ was significantly better for the HF group overall (91.2 (95 % CI = 89.6-92.9) vs. 88.3 (95 % CI = 86.1-90.5); p = .036), and in one site. HQ in the TAU group was much more variable than the HF group overall (W (mean) = 24.7; p < .001) and in four of five sites. Unit/building HQ scores were positively associated with housing stability: (73.4 (95 % CI 68.3-78.5) for those housed none of the time; 91.1 (95 % CI 89.2-93.0) for those housed some of the time; and 93.1 (95 % CI 91.4-94.9)) for those housed all of the time (F = 43.9 p < .001). This association held after adjusting for site, housing characteristics, participant ethnocultural status, community functioning, and social support. This study demonstrates that HQ can be as good or better, and less variable, in HF programs in Canada that systematically and predominantly source housing stock from the private sector compared to housing procured outside of an HF program. HQ is also an important predictor of housing stability outcomes.

Tenants with additional needs: when housing first does not solve homelessness.

BACKGROUND: At Home/Chez-Soi was a 24 month randomized controlled trial of Housing First (HF) conducted in five Canadian cities. AIMS: This article attempts to identify the characteristics of participants who experienced housing instability one year after entering HF. METHODS: Those defined as experiencing housing instability were housed <50% of the last 9 months of the first year, excluding time in institutions, unless they were housed 100% of the past 3 months. RESULTS: Only 13.5% of HF participants (n = 157/1162) met criteria for housing instability. Several variables were significant predictors of instability in between-group comparisons and multiple regression analyses: residence in Winnipeg, cumulative lifetime homelessness, percent of previous 3 months spent in jail, and community psychological integration; while residence in Moncton and a diagnosis of PTSD or panic disorder predicted stability. The predictive models were weak, identifying correctly only 3.8% of individuals that failed to achieve housing stability. CONCLUSIONS: It is not possible to predict confidently at baseline who will experience early housing instability in HF. There are certain individual characteristics that might be considered risk factors. Providing HF to all individuals who qualify for a HF program remains the most valid way to administer admission to housing.

Employment and Income of People Who Experience Mental Illness and Homelessness in a Large Canadian Sample.

OBJECTIVES: Research suggests that homeless people with mental illness may have difficulty obtaining employment and disability benefits. Our study provides a comprehensive description of sources of income and employment rates in a large Canadian sample. METHODS: Participants (n = 2085) from the 5 sites of the At Home/Chez Soi study were asked about their income, employment, and desire for work during the pre-baseline period. The proportion of participants employed, receiving government support, and relying on income from other activities were compared across sites, as were total income and income from different sources. Generalized linear models were used to identify participant characteristics associated with total income. RESULTS: Unemployment ranged from 93% to 98% across 5 sites. The per cent of participants who wanted to work ranged from 61% to 83%. Participants relied predominantly on government assistance, with 29.5% relying exclusively on welfare, and 46.2% receiving disability benefits. Twenty-eight per cent of participants received neither social assistance nor disability income. Among the 2085 participants, 6.8% reported income from panhandling, 2.1% from sex trade, and 1.2% from selling drugs. Regression models showed that income differed significantly among sites and age groups, and was significantly lower for people with psychotic illnesses. CONCLUSION: These results suggest that homeless people with mental illness are predominantly unemployed, despite expressing a desire to work. In Canada, this group relies predominantly on welfare, but has access to disability benefits and employment insurance. These findings highlight the importance of developing effective interventions to support employment goals and facilitate access to benefits.

Development and initial validation of the Observer-Rated Housing Quality Scale (OHQS) in a multisite trial of housing first.

Quality of housing has been shown to be related to health outcomes, including mental health and well-being, yet "objective" or observer-rated housing quality is rarely measured in housing intervention research. This may be due to a lack of standardized, reliable, and valid housing quality instruments. The objective of this research was to develop and validate the Observer-Rated Housing Quality Scale (OHQS) for use in a multisite trial of a "housing first" intervention for homeless individuals with mental illness. A list of 79 housing unit, building, and neighborhood characteristics was generated from a review of the relevant literature and three focus groups with consumers and housing service providers. The characteristics were then ranked by 47 researchers, consumers, and service providers on perceived importance, generalizability, universality of value, and evidence base. Items were then drafted, scaled (five points, half values allowed), and pretested in seven housing units and with seven raters using cognitive interviewing techniques. The draft scale was piloted in 55 housing units in Toronto and Winnipeg, Canada. Items were rated independently in each unit by two trained research assistants and a housing expert. Data were analyzed using classical psychometric approaches and intraclass correlation coefficients (ICC) for inter-rater reliability. The draft scale consisted of 34 items assessing three domains: the unit, the building, and the neighborhood. Five of 18 unit items and 3 of 7 building items displayed ceiling or floor effects and were adjusted accordingly. Internal consistency was very good (Cronbach's alpha = 0.90 for the unit items, 0.80 for the building items, and 0.92 total (unit and building)). Percent agreement ranged from 89 to 100 % within one response scale value and 67 to 91 % within one half scale value. Inter-rater reliability was also good (ICCs were 0.87 for the unit, 0.85 for the building, and 0.93 for the total scale). Three neighborhood items (e.g., distance to transit) were found to be most efficiently rated using publicly available information. The physical quality of housing can be reliably rated by trained but nonexpert raters using the OHQS. The tool has potential for improved measurement in housing-related health research, including addressing the limitations of self-report, and may also enable documenting the quality of housing that is provided by publicly funded housing programs.

Relationship between adverse childhood experiences and homelessness and the impact of axis I and II disorders.

OBJECTIVES: We investigated the links between homelessness associated with serious mental and physical healthy disparities and adverse childhood experiences (ACEs) in nationally representative data, with Axis I and II disorders as potential mediators. METHODS: We examined data from the National Epidemiologic Survey of Alcohol and Related Conditions in 2001-2002 and 2004-2005, and included 34,653 participants representative of the noninstitutionalized US population who were 20 years old or older. We studied the variables related to 4 classes of Axis I disorders, all 10 Axis II personality disorders, a wide range of ACEs, and a lifetime history of homelessness. RESULTS: Analyses revealed high prevalences of each ACE in individuals experiencing lifetime homelessness (17%-60%). A mediation model with Axis I and II disorders determined that childhood adversities were significantly related to homelessness through direct effects (adjusted odd ratios = 2.04, 4.24) and indirect effects, indicating partial mediation. Population attributable fractions were also reported. CONCLUSIONS: Although Axis I and II disorders partially mediated the relationship between ACEs and homelessness, a strong direct association remained. This novel finding has implications for interventions and policy. Additional research is needed to understand relevant causal pathways.