Substance use among persons with serious mental illness in eastern Ontario.

One hundred and eighty persons with serious mental illness (SMI) in eastern Ontario, receiving services from assertive community treatment teams in Brockville and Kingston were interviewed about substance use. Data were compared to survey findings for the Ontario population. Tobacco use was higher among both men and women in the SMI sample, but use of alcohol and drugs in the past 12 months was lower than population data. The frequency of alcohol use was significantly greater than drug use among the SMI sample.