Using brief self-reports and clinician scales to screen for substance use disorders in psychotic patients

The aims of this study were to examine evidence for the concurrent validity of two self-report measures and two staff-report measures measuring alcohol and drug problems in seriously mentally ill people and to examine if psychotic patients under-report their alcohol and drug problems in an early intervention clinic.

This is a cross-sectional study of 48 patients (26 inpatients and 22 outpatients) from an early intervention clinic for psychosis. To examine the sensitivity and specificity, we compared both the staff-report measures Clinical Alcohol Use Scale (AUS) and Clinical Drug Use Scale (DUS) and the self-report measures Short Michigan Alcohol Screening Test (SMAST-13) and Drug Abuse Screening Test (DAST-20), with the current ICD-10 diagnostic criteria as the gold-standard for alcohol and drug problems. To examine whether the patients under-report their alcohol and drug problems, we also compared the self-report measures SMAST-13 and DAST-20 with the staff-report measures AUS and DUS and ICD-10 consensus substance abuse diagnoses.

The results show that the concurrent validity compared with ICD-10 diagnoses was moderate for both the staff-report measures AUS and DUS and for the self-report measures SMAST-13 and DAST-20. Three out of seven patients under-report alcohol problems and one patient out of seven under-report drug use problems according to consensus ICD-10 substance abuse diagnoses.

We conclude that the SMAST-13 and DAST-20 in combination with the AUS and DUS, which are easy and quick to perform, are helpful in establishing a common understanding of the patient's alcohol and drug problems in an early intervention clinic.