Although the Indians in this sample had high rates of cannabis dependence (43 percent for men and 24 percent for women), cannabis-induced psychiatric disorders were present in 1 percent or less of the sample. No significant co-occurrence of cannabis dependence and independent psychiatric disorders was found. The findings suggest that in this group of Southwest California Indians, cannabis use in and of itself, might infrequently cause induced major depression and mania, but not other induced psychiatric disorders, including induced psychotic disorders. These findings do not rule out the possibility that cannabis plays some role in facilitating the development of psychotic disorders or other induced psychiatric disorders. Two hundred and seven men and 306 women participated in this study. They were recruited from six reservations in six adjoining geographic areas. A questionnaire obtained information on demographics, personal medical history, ethnicity, and substance-use history. No individuals with detectable blood alcohol levels were included in the study. Each participant was administered the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA). The SSAGA determined lifetime rates of cannabis-use disorders (cannabis abuse and dependence); four anxiety disorders (panic disorder with or without agoraphobia, agoraphobia without panic, social phobia, and obsessive-compulsive disorder); three affective disorders (major depressive disorder, bipolar I disorder, and dysthymic disorder); and nonbipolar I psychotic disorders (acute and chronic). 2 tables and 73 references