Prevalence studies of substance-related disorders: a systematic review of the literature.

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.