Pilot study on the effects of fenfluramine on negative symptoms in twelve schizophrenic inpatients

We treated 12 chronic schizophrenic inpatients with fenfluramine, an anorexigenic drug that depletes serotonin, to test the hypothesis that the "negative" symptoms of schizophrenia might be related to brain serotonin activity. We measured change in both positive and negative symptoms in a double-blind, parallel-design trial of fenfluramine or placebo. Negative symptoms improved over time in some individuals within the active treatment group, but not in individuals within the placebo group. However, group comparisons of active treatment versus placebo were not significant.