Platelet monoamine oxidase activity and deficit syndrome schizophrenia

Measures of affective flattening that combine self-reported emotional experience with observed affect may identify deficit syndrome patients better than ratings based on observed affect alone. In this study, we examined 23 clinically stable but chronically ill schizophrenic patients, 15 of whom were found to have a deficit syndrome. After exclusion of patients with self-reported depressed mood from the deficit syndrome group, the remaining patients with a deficit syndrome not accompanied by self-reported depressed mood showed a strikingly homogeneous distribution of platelet monoamine oxidase activity. Results suggest that inclusion of self-reported emotional experience in clinical definitions of the deficit syndrome will increase the specificity of diagnosis.