Coexisting psychiatric disorders in a New Zealand outpatient alcohol and other drug clinical population

Objective: To describe the extent of psychiatric disorder and mental health service utilization in a representative outpatient alcohol and other drug (AOD) treatment sample in New Zealand. Method: A total of 105 patients were randomly recruited from two outpatient AOD treatment services in New Zealand and completed a diagnostic interview within the first 2 months of treatment. Axis I psychiatric diagnoses were made using the computerized Composite International Diagnostic Interview (CIDI‐Auto), and were supplemented by the South Oaks Gambling Scale (SOGS) and the conduct disorder and antisocial personality disorder section of the Diagnostic Interview for Genetic Studies (DIGS). Results: Seventy‐four per cent of the sample had a current non‐substance or gambling axis I disorder, with a lifetime rate of 90%. The most commonly diagnosed of these coexisting psychiatric disorders were major depressive episode (34%), social phobia (31%) and posttraumatic stress disorder (31%). Past contact with mental health services was common, while contact at the time of baseline assessment was uncommon. Conclusions: Coexisting psychiatric disorder was the rule and not the exception in this sample. AOD patients are clearly part of the larger population of mental health patients. AOD services need to be capable of comprehensive assessment and treatment planning, which includes coexisting psychiatric disorders, and should work toward better integration with other mental health services.