Amisulpride is a substituted benzamide with high selectivity for dopamine D2 and D3 receptors. The purpose of the study was to evaluate the effect of 100 mg amisulpride in patients with predominantly negative symptoms of schizophrenia.

This was a multi-centre, randomised, parallel-group, double-blind study. Patients received either amisulpride (100 mg/day) or placebo over a six-month treatment period.

A total of 141 patients were included, 69 received amisulpride, 72 placebo. Fifty-eight patients (41%) had received neuroleptic treatment prior to inclusion. The percentage of amisulpride patients completing the study (55%) was significantly higher than that with placebo (32%), and drop-out rates due to lack of efficacy were 27% with amisulpride and 47% with placebo. All efficacy assessments were statistically in favour of amisulpride compared with placebo. The overall incidence of extrapyramidal symptoms was comparable in both groups; only five patients started anti-Parkinsonian treatment during the study (one in the placebo and four in the amisulpride group).

Amisulpride is effective in the medium-term treatment schizophrenic patients with predominantly negative symptoms.