One-year, low-dose neuroleptic study of in-patients with chronic schizophrenia characterised by persistent negative symptoms

BACKGROUND: Amisulpride is a potent substituted benzamide antipsychotic drug claimed to improve the negative symptoms of schizophrenia, particularly at low dosage. METHOD: Sixty long-term in-patients with schizophrenia and selected for predominant negative symptoms were randomised to receive either haloperidol or amisulpride. Over a year there was systematic dose reduction, as symptoms allowed. RESULTS: There were no significant differences between the treatment groups in the proportion receiving low-dose treatment, the control of positive symptoms, or ratings of social behaviour, side-effects or tardive dyskinesia. For negative symptoms, there were consistent but non-significant trends in favour of amisulpride. The amisulpride patients required significantly less anticholinergic medication. CONCLUSIONS: In chronically-hospitalised in-patients with schizophrenia characterised by persistent negative symptoms, amisulpride was a well-tolerated maintenance antipsychotic medication. The drug had only a limited effect in reducing negative symptoms, which were relatively stable, enduring phenomena in this sample, despite dosage reduction.