摘要：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. Homelessness is a serious societal problem. Approximately 12% to 14% of adults in the United States report a history of homelessness. 1–3 In addition to poverty, homelessness has been associated with the deterioration of mental and physical health, social isolation, and exposure to traumatic events. 4–6 Furthermore, those who have experienced homelessness have significantly elevated mortality rates and high rates of suicidal behavior. 7,8 Worldwide, homelessness has been found to be overrepresented in men and those groups that traditionally experience discrimination. 2 Although systemic societal factors (e.g., lack of affordable housing) affect how many individuals are homeless at any given time, demographic characteristics and life histories put specific individuals at risk for this detrimental experience. 9 Childhood adversities are found to be substantially overrepresented in homeless samples, and a history of childhood adversity has been related to particularly poor outcomes among the homeless. 9,10 Previous research, however, has a number of limitations. Nearly all studies used interview methodology of currently sheltered homeless or clinical populations, who might have elevated risk factors or be chronically homeless. 10,11 These studies generally lacked a suitable sociodemographic comparison group and tended to focus on homeless individuals within a specific geographic area. 9,12 In addition, all of the other research used relatively small sample sizes not representative of the general US population. The only known epidemiological study investigating homelessness and childhood adversity found evidence of an association between childhood adversity and lifetime homelessness. 13 However, this study investigated limited types of adversities, and used a broad definition of lifetime homelessness, which was inconsistent with standardized definitions of homelessness that imply being homeless for longer periods of time. 13 The main objective of our study was to better describe and understand the relationship between childhood adversities and future homelessness in a nationally representative sample. We further addressed many of the limitations in the current literature by using the National Epidemiologic Survey of Alcohol and Related Conditions (NESARC) to investigate whether a history of different childhood adversities were associated with increased odds of developing lifetime homelessness. Additionally, we investigated whether Axis I and Axis II Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ( DSM-IV ) 14 mental disorders mediated these relationships. The rationale for investigating mental disorders as a mediator variable stems from a public health interest to better describe co-occurring patterns linking childhood adversity and homelessness. The high prevalence of poor mental health outcomes in those with a history of foster care or other childhood adversities is well documented. 9,15–17 Additionally, the prevalence of mental disorders and addictions is significantly higher among homeless people than in the general population; these disorders are often comorbid. 18–20 Mental disorders among people who are homeless include severe and persistent mental illnesses, such as schizophrenia, as well as more prevalent conditions, such as mood and affective disorders. 20 Investigating mental disorders as a possible mediator provides a more in-depth consideration of the multiple vulnerabilities faced by homeless individuals and may help to identify differential intervention opportunities. To our knowledge, our study is the first to examine the link between childhood adversity and lifetime homelessness in a large, nationally representative sample. Investigating this link in such a sample with an adequate control group of participants who have not experienced homelessness was essential in understanding the link between adversity and homelessness above and beyond factors such as income or education. Furthermore, by examining the potential mediating role of mental disorders, we hoped to better elucidate the complex factors linking childhood adversity to homelessness and to inform appropriate points for intervention.
