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 Canada's substance abuse and mental health services should continue to ensure that adequate attention is directed to the needs of people with co-occurring disorders.

Objective: To examine the prevalence and profile of people with co-occurring mental and substance use disorders in relation to numerous demographic, diagnostic, and needs-related variables across a comprehensive system of mental health services using a standard methodology. Method: Data were collected on cases ( n = 9839) sampled from specialty tertiary inpatient, specialty outpatient, and community-based mental health programs. Status with respect to co-occurring disorders was based on recorded diagnosis of substance use disorder and the substance abuse measure within the Colorado Client Assessment Record. The demographic and needs profile was compared across groups with or without co-occurring disorders within each level of care. Results: Overall, the prevalence of co-occurring disorders was 18.5%, and highest among clients receiving specialty tertiary inpatient care (28%), and within selected subpopulations such as younger adults (55%) and those with personality disorders (34%). There were few differences between groups based on co-occurring disorders in the specialty inpatient programs. For outpatient and community settings, the clients with co-occurring disorders were distinguished by a more impaired and complex needs profile and more likely to be young, single, male, and of low education. Across all levels of care, having a co-occurring disorder was strongly associated with antisocial and challenging behaviour, legal involvement, and risk of suicide or self-harm. Conclusion: The prevalence estimate of co-occurring disorders is likely representative of a multilevel system of care that serves a large, mixed urban and rural population. Results highlight the need to focus on specific subpopulations and sectors in pursuit of more integrated treatment and support for their mental health and addictions problems.

It is well known that only a relatively small proportion of people in the community who experience substance use problems seek assistance from the specialized sector of services that have been commissioned to provide treatment and support for these problems. Going back to seminal reports from the early 1990s there has been a call for a systems approach to “broaden the base of treatment” in order to achieve wider coverage and yield positive outcomes at a population level. In some jurisdictions conceptual models referred to as “tiered models” have been advanced to support planning, system design and performance monitoring. This paper traces the evolution of such tiered models for substance use services and describes a recent model advanced in Ontario Canada for design of an integrated system of mental health, substance use and problem gambling services and supports. The paper concludes by highlighting key features and principles of the tiered approach that are critical for its actual operationalization. Some challenges operationalizing such a comprehensive system design framework are also noted.

This article examines the effectiveness of quarterly Recovery Management Checkups (RMCs) for people with substance disorders by level of co-occurring mental disorders (34% none, 27% internalizing disorders, and 39% internalizing and externalizing) across two randomized experiments with 92% to 97% follow-up. The 865 participants are 82% African American, 53% female, and age 37 on average. RMC involves identification of those in need of treatment, motivational interviews, and treatment linkage assistance. It is effective in linking participants in need to treatment, with equal or better outcomes among those with more mental disorders. The data support the utility of monitoring and re-intervention for clients with co-occurring disorders.