Identification of the alcoholic schizophrenic: use of clinical laboratory tests and the MAST

A screening procedure to identify alcohol abuse among schizophrenics is sorely needed. We evaluated the utility of a particular screening battery that consisted of three standard clinical laboratory tests (GGTP, MCV, SGOT) and the Michigan Alcoholism Screening Test (MAST). Consecutive admissions to an acute psychiatric unit and to an alcohol rehabilitation program were initially evaluated for inclusion in three diagnostic groupings: alcoholic schizophrenics, nonalcoholic schizophrenics and nonschizophrenic alcoholics. Twenty inpatient veterans were selected for each diagnostic group. These groups were then compared in terms of scores on the GGTP, MCV, SGOT and MAST. The MAST had the greatest sensitivity, but suffered low specificity. The GGTP demonstrated excellent specificity, but very poor sensitivity. When multiple tests were considered, the combination of the MAST and GGTP proved the best at identifying alcohol abuse in schizophrenics. The false positive rate was unacceptably high, however. The test battery was not useful in discriminating between nonalcoholic schizophrenics and alcoholic schizophrenics, yet could distinguish the nonschizophrenic alcoholics from the two schizophrenic groups.