Diagnostic subgroups within a sample of comorbid substance abusers: correlates and characteristics.

Patients seeking treatment at the Addiction Research Foundation for a substance problem but who also reported psychiatric symptomatology were referred to the Mental Health Unit. Following a clinical psychiatric interview, these patients were categorized into one of six diagnostic subgroups based on the presence of DSM-III-R psychiatric disorders: mood, anxiety, psychotic, organic, Axis-II, and adjustment. A control group of patients referred to the Mental Health Unit but not diagnosed with a psychiatric disorder was also included. These groups were compared on several demographic, substance use, and psychiatric variables. Patients assigned a diagnosis of organic (substance-induced) and Axis II disorders were found to have more severe substance use histories, alcohol-related consequences and longer treatment histories. Patients with a diagnosis of adjustment disorder appeared to be functioning relatively better. Implications of studying the heterogeneity of comorbidity are discussed.