Julian M. Somers

Prevalence and Incidence Studies of Anxiety Disorders: A Systematic Review of the Literature

This is the second in a series of papers that present systematic reviews of the prevalence and incidence of psychiatric disorders drawn from studies published in English literature in the years 1980 to 2000. The series discusses the implications of these epidemiologic findings to mental health policy and practice. Objective: To present the results of a systematic review of literature published between January 1, 1980, and December 31, 2000, that reports findings on the prevalence and incidence of mood disorders in both general population and primary care settings. Method: We conducted a literature search of epidemiologic studies of mood disorders, using Medline and HealthSTAR databases and canvassing English-language publications. Eligible publications were restricted to studies that examined subjects aged at least 15 years and over. We used a set of predetermined inclusion and exclusion criteria to identify relevant studies. We extracted and analyzed prevalence and incidence data for heterogeneity. Results: Of general population studies, a total of 18 prevalence and 5 incidence studies met eligibility criteria. We found heterogeneity across 1-year and lifetime prevalence of major depressive disorder (MDD), dysthymic disorder, and bipolar I disorder. The corresponding pooled rates for 1-year prevalence were 4.1 per 100, 2.0 per 100, and 0.72 per 100, respectively. For lifetime prevalence, the corresponding pooled rates were 6.7 per 100, 3.6 per 100, and 0.8 per 100, respectively. Significant variation was observed among 1-year incidence rates of MDD, with a corresponding pooled rate of 2.9 per 100. Conclusions: The prevalence of mood disorders reported in high-quality studies is generally lower than rates commonly reported in the general psychiatric literature. When controlled for common methodological confounds, variation in prevalence rates persists across studies and deserves continued study. Methodological variation among studies that have examined the prevalence of depression in primary health care services is so large that comparative analyses cannot be achieved.

Prevalence and incidence studies of schizophrenic disorders: a systematic review of the literature.

Objective: To present the results of a systematic review of the literature published between January 1, 1980, and December 31, 2000, that reports findings on the prevalence and incidence of schizophrenia and related disorders. Method: We conducted a literature search of schizophrenia-related epidemiological studies, using Medline and HealthSTAR databases and canvassing English-language publications. We used a set of predetermined inclusion-exclusion criteria to identify relevant studies. Eligible publications were restricted to age ranges of 18 years and over for prevalence studies and 15 years and over for incidence studies. Prevalence and incidence data were extracted and analyzed for heterogeneity. Results: A total of 18 prevalence and 8 incidence studies met eligibility criteria for the review. Heterogeneity analysis revealed significant differences across 1-year and lifetime prevalence and 1-year incidence of schizophrenia. The corresponding pooled rates were: 0.34 per 100, 0.55 per 100, and 11.1 per 100 000, respectively; the variation in rates between studies was generally between 2- and 5-fold. Conclusions: Although we restricted this review to studies using rigorous and relatively homogeneous methods, there remains significant heterogeneity of prevalence and incidence rates. This strengthens support for the hypothesis that there is real variation in the distribution of schizophrenia around the world. Health planners need to have local data on schizophrenia rates to improve the accuracy of their interventions, while clinicians and researchers need to continue to investigate the etiology of this variation.

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

Introduction Housing First is a complex housing and support intervention for homeless individuals with mental health problems. It has a sufficient knowledge base and interest to warrant a test of wide-scale implementation in various settings. This protocol describes the quantitative design of a Canadian five city,

Prevalence of co-occurring substance use and other mental disorders in the Canadian population.

110 million demonstration project and provides the rationale for key scientific decisions. Methods A pragmatic, mixed methods, multi-site field trial of the effectiveness of Housing First in Vancouver, Winnipeg, Toronto, Montreal and Moncton, is randomising approximately 2500 participants, stratified by high and moderate need levels, into intervention and treatment as usual groups. Quantitative outcome measures are being collected over a 2-year period and a qualitative process evaluation is being completed. Primary outcomes are housing stability, social functioning and, for the economic analyses, quality of life. Hierarchical linear modelling is the primary data analytic strategy. Ethics and dissemination Research ethics board approval has been obtained from 11 institutions and a safety and adverse events committee is in place. The results of the multi-site analyses of outcomes at 12 months and 2 years will be reported in a series of core scientific journal papers. Extensive knowledge exchange activities with non-academic audiences will occur throughout the duration of the project. Trial registration number This study has been registered with the International Standard Randomised Control Trial Number Register and assigned ISRCTN42520374.

A Multiple-City RCT of Housing First With Assertive Community Treatment for Homeless Canadians With Serious Mental Illness

Objective: Population health surveys around the world have studied the epidemiology of comorbid substance use disorders (SUDs) and other mental disorders as part of larger efforts to assess needs and direct integrated planning and delivery of services. This study presents the first national assessment in Canada of the prevalence of co-occurring SUDs and other mental disorders, with attention to differences by substance problem severity, sex, age, and region. Methods: This work is a secondary analysis of data from the 2002 Canadian Community Health Survey: Mental Health and Well-Being. The sample was obtained using a multistage stratified cluster design (n = 36 984, response rate = 77%). Results: The 12-month population prevalence of co-occurring disorders was 1.7%. The 12-month prevalence of other mental disorders was higher among those with illicit drug, relative to alcohol, problems and among those with dependence, compared with those with less severe problems. Sex and age differences mirrored population differences in pure disorders. Salient regional differences included the higher rate of co-occurring disorders in British Columbia and the lower rates in Quebec. Conclusions: Cross-study comparisons are hampered by methodological differences; however, these Canadian rates are at the lower end of the range reported internationally. This might have resulted from the exclusion of several disorders known to be highly comorbid with SUDs. Nonetheless, prevalence is high in certain subgroups, and efforts under way to improve Canadas substance abuse and mental health services should continue to ensure that adequate attention is directed to the needs of people with co-occurring disorders.

Housing first improves residential stability in homeless adults with concurrent substance dependence and mental disorders.

OBJECTIVE Housing First with assertive community treatment (ACT) is a promising approach to assist people with serious mental illness to exit homelessness. The article presents two-year findings from a multisite trial on the effectiveness of Housing First with ACT. METHODS The study design was a randomized controlled trial conducted in five Canadian cities. A sample of 950 participants with serious mental illness who were absolutely homeless or precariously housed were randomly assigned to receive either Housing First with ACT (N=469) or treatment as usual (N=481). RESULTS Housing First participants spent more time in stable housing than participants in treatment as usual (71% versus 29%, adjusted absolute difference [AAD]=42%, p<.01). Compared with treatment-as-usual participants, Housing First participants who entered housing did so more quickly (73 versus 220 days, AAD=146.4, p<.001), had longer housing tenures at the study end-point (281 versus 115 days, AAD=161.8, p<.01), and rated the quality of their housing more positively (adjusted standardized mean difference [ASMD]=.17, p<.01). Housing First participants reported higher quality of life (ASMD=.15, p<.01) and were assessed as having better community functioning (ASMD=.18, p<.01) over the two-year period. Housing First participants showed significantly greater gains in community functioning and quality of life in the first year; however, differences between the two groups were attenuated by the end of the second year. CONCLUSIONS Housing First with ACT is an effective approach in various contexts for assisting individuals with serious mental illness to rapidly exit homelessness.

Housing First Reduces Re-offending among Formerly Homeless Adults with Mental Disorders: Results of a Randomized Controlled Trial

OBJECTIVES We examined the relationship between substance dependence and residential stability in homeless adults with current mental disorders 12 months after randomization to Housing First programs or treatment as usual (no housing or support through the study). METHODS The Vancouver At Home study in Canada included 2 randomized controlled trials of Housing First interventions. Eligible participants met the criteria for homelessness or precarious housing, as well as a current mental disorder. Residential stability was defined as the number of days in stable residences 12 months after randomization. We used negative binomial regression modeling to examine the independent association between residential stability and substance dependence. RESULTS We recruited 497 participants, and 58% (n = 288) met the criteria for substance dependence. We found no significant association between substance dependence and residential stability (adjusted incidence rate ratio = 0.97; 95% confidence interval = 0.69, 1.35) after adjusting for housing intervention, employment, sociodemographics, chronic health conditions, mental disorder severity, psychiatric symptoms, and lifetime duration of homelessness. CONCLUSIONS People with mental disorders might achieve similar levels of housing stability from Housing First regardless of whether they experience concurrent substance dependence.

Prevalence Studies of Substance-Related Disorders: A Systematic Review of the Literature

Background Homelessness and mental illness have a strong association with public disorder and criminality. Experimental evidence indicates that Housing First (HF) increases housing stability and perceived choice among those experiencing chronic homelessness and mental disorders. HF is also associated with lower residential costs than common alternative approaches. Few studies have examined the effect of HF on criminal behavior. Methods Individuals meeting criteria for homelessness and a current mental disorder were randomized to one of three conditions treatment as usual (reference); scattered site HF; and congregate HF. Administrative data concerning justice system events were linked in order to study prior histories of offending and to test the relationship between housing status and offending following randomization for up to two years. Results The majority of the sample (67%) was involved with the justice system, with a mean of 8.07 convictions per person in the ten years prior to recruitment. The most common category of crime was “property offences” (mean = 4.09). Following randomization, the scattered site HF condition was associated with significantly lower numbers of sentences than treatment as usual (Adjusted IRR = 0.29; 95% CI 0.12–0.72). Congregate HF was associated with a marginally significant reduction in sentences compared to treatment as usual (Adjusted IRR = 0.55; 95% CI: 0.26–1.14). Conclusions This study is the first randomized controlled trial to demonstrate benefits of HF among a homeless sample with mental illness in the domain of public safety and crime. Our sample was frequently involved with the justice system, with great personal and societal costs. Further implementation of HF is strongly indicated, particularly in the scattered site format. Research examining interdependencies between housing, health, and the justice system is indicated. Trial registration ISRCTN57595077

Trajectories of recovery among homeless adults with mental illness who participated in a randomised controlled trial of Housing First: a longitudinal, narrative analysis

Objective: To present the results of a systematic review of literature published between January 1, 1980, and December 31, 2000, that reports epidemiologic estimates of substance-related disorders. Method: We conducted a literature search of substance-related epidemiologic studies, using medline and HealthSTAR databases and applying a set of predetermined inclusion and exclusion criteria to identify relevant studies. We extracted and analyzed prevalence and incidence data for heterogeneity. Results: A total of 19 prevalence studies of substance-related disorders met inclusion criteria for this review. Heterogeneity analyses revealed significant variability across 1-year and lifetime prevalence of both alcohol and other substance use disorders. The corresponding 1-year and lifetime pooled rates were 6.6 per 100 and 13.2 per 100, respectively, for alcohol use disorders and 2.4 per 100 and 2.4 per 100, respectively, for other substance use disorders. We observed variability among countries and also among regions within the same country. In contrast to other drug problems, alcohol use disorders were substantially more common, were more likely to occur among male subjects, and were more likely to be associated with abuse symptoms. For other drugs, dependence was consistently more prevalent than abuse. Conclusions: Studies using rigorous and comparable methodologies report significant variability in rates of alcohol and other substance use disorders. These data suggest that different policies and regional practices are associated with variability in rates of disorders. Policy-makers and health planners require regular, regionally sensitive estimates of prevalence rates to respond effectively to unique patterns of need in their constituencies.

Multiple Paths to Just Ends: Using Narrative Interviews and Timelines to Explore Health Equity and Homelessness

Objectives This study used longitudinal, narrative data to identify trajectories of recovery among homeless adults with mental illness alongside the factors that contribute to positive, negative, mixed or neutral trajectories over time. We expected that participants who received Housing First (HF) would describe more positive trajectories of recovery than those who were assigned to Treatment as Usual (TAU; no housing or support provided through the study). Design Narrative interview data were collected from participants at baseline and 18 months after random assignment to HF or TAU. Setting Participants were sampled from the community in Vancouver, British Columbia. Participants Fifty-four participants were randomly and purposively selected from the larger trial; 52 were interviewed at baseline and 43 were reinterviewed 18 months after randomisation. Method Semistructured interviews were conducted at both time points. For each participant, paired baseline and follow-up narratives were classified as positive, negative, mixed or neutral trajectories of recovery, and thematic analysis was used to identify the factors underlying different trajectories. Results Participants assigned to HF (n=28) were generally classified as positive or mixed trajectories; those assigned to TAU (n=15) were generally classified as neutral or negative trajectories. Positive trajectories were characterised by a range of benefits associated with good-quality, stable housing (eg, reduced substance use, greater social support), positive expressions of identity and the willingness to self-reflect. Negative, neutral and mixed trajectories were characterised by hopelessness (‘things will never get better’) related to continued hardship (eg, eviction, substance use problems), perceived failures and loss. Conclusions HF is associated with positive trajectories of recovery among homeless adults with mental illness. Those who did not receive housing or support continued to struggle across a wide range of life domains. Findings are discussed with implications for addressing services and broader social change in order to benefit this marginalised population.