The prevalence of marijuana (cannabis) use and dependence in cocaine dependence.

In a retrospective and prospective study using DSM-III-R criteria for substance dependence in 232 inpatients and 51 outpatients, the clinical suspicion that cocaine addicts use other drugs including marijuana was confirmed. As many as 53% of cocaine addicts diagnosed by DSM-III-R criteria for cocaine dependence qualified for a diagnosis of cannabis dependence. The reports regarding marijuana and other drug dependence among cocaine addicts have been few and inconclusive. The diagnosis of other drug use and dependence in cocaine dependence has importance with regard to prognosis and treatment. This study found a high prevalence of marijuana (cannabis) dependence in patients with cocaine dependence.