Each participant also completed an interview with the SSAGA (Bucholz et al. 1994), which was used to collect demographic information, make lifetime substance dependence and psychiatric disorder diagnoses according to DSM-III-R criteria (American Psychiatric Association, 1987), and collect other information on cannabis use and use related symptomatology. The SSAGA is a fully structured, poly-diagnostic psychiatric interview that has undergone both reliability and validity testing (Bucholz et al. 1994; Hesselbrock et al. 1999). It has been used in another Native American sample (Hesselbrock et al. 2000; Hesselbrock et al. 2003). Interviewers were trained by personnel from COGA. All best final diagnoses were made by a research psychiatrist/addiction specialist (DAG).
