Evaluation of a motivational interview for substance use within psychiatric in-patient services

Aims To assess the effectiveness of a motivational interview among hospitalized psychiatric patients with comorbid substance use disorder in reducing alcohol and other drug (Ail use. Design Subjects were assigned randomly to receive an individual motivational interview (n = 79) or a self-help booklet (control condition; n = 81). Setting Subjects were volunteers recruited from a major public psychiatric hospital. Participants Subjects met abuse or dependence criteria on the structured clinical interview for diagnosis (SCID) for alcohol, cannabis or amphetamine or they reported hazardous use during the last month of one or more of these drug types on the opiate treatment index (OTI). Intervention Either one 30-45-minute motivational interview or brief advice. Measurements The SCID and OTI were the main measures. Findings There was a modest short-term effect of the motivational interview on an aggregate index of alcohol and other drug use (polydrug use on the OTI). Cannabis use remained high among the sample over the 12-month follow-up period. Conclusion Although motivational interviewing appears feasible among in-patients in psychiatric hospital with comorbid substance use disorders, more extensive interventions are recommended, continuing on an outpatient basis, particularly for cannabis use.