The reliability and validity of the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) in first-episode psychosis

Abstract

Aims The Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) is a brief, easily administered, valid and reliable screening instrument for all psychoactive substances in drug treatment and primary care settings. This study aims to determine the reliability and validity of the ASSIST for detecting substance use disorders in first-episode psychosis. Participants Participants were 214 first-episode psychosis patients attending the Early Psychosis Prevention and Intervention Centre (EPPIC) in Melbourne, Australia. Measurements Participants were administered the ASSIST, Alcohol Use Disorders Identification Test (AUDIT), the Severity of Dependence Scale (SDS) and the Brief Psychiatric Rating Scale (BPRS). Presence of DSM-IV substance abuse and dependence disorders in the previous 12 months was assessed using the Structured Clinical Interview for DSM-IV (SCID-IV). Findings The ASSIST total substance involvement (TSI) score and specific substance involvement (SSI) scores for cannabis, alcohol and amphetamine use demonstrated high levels of internal consistency and acceptable levels of concurrent and discriminative validity. Individuals with cutoff scores of ≥ 2, 4 and 1 on the ASSIST cannabis, alcohol and amphetamine SSI scores were 5 to 6 times more likely to meet the diagnostic criteria for these substance use disorders. Conclusions The ASSIST is a psychometrically sound measure of cannabis, alcohol and amphetamine use disorders in first-episode psychosis.