Screening for concomitant alcohol abuse in schizophrenia: clinical significance of the Munich Alcoholism Test and laboratory tests.

For the early and correct diagnosis of the comorbidity of schizophrenia and alcoholism, a valid laboratory marker would be most helpful in clinical practice. Seventy schizophrenics admitted to a general psychiatric unit of an urban hospital located in a large industrial area in Germany prospectively underwent a detailed addiction history, the Munich Alcoholism Test (MALT) and determinations of serum gamma-glutamyltransferase (gammaGT) and carbohydrate-deficient transferrin (CDT). Cutoff levels for laboratory tests represented the 95th percentile of data obtained from 100 matched healthy controls. Using the MALT, we found evidence of concomitant alcohol consumption in 42.8% of the study patients. The sensitivities of gammaGT and CDT for detecting alcohol abuse (confirmed using DSM III-R criteria) were 70.6 and 58.8%, respectively. Our data suggest that the MALT can be used as a reliable screening test for alcohol use in schizophrenia. In neuroleptic-treated schizophrenics with pathological gammaGT, but low MALT scores, the corresponding CDT may serve as a highly specific marker to verify a concomitant alcohol abuse.