TREATMENT OF NEGATIVE SYMPTOMS IN SCHIZOPHRENIA WITH AMISULPRIDE

Background. The efficacy of low doses of certain neuroleptics in impro ving negative symptoms is still controversial. This study assessed the efficacy of amisulpride, a benzamide which increases dopaminergic tra nsmission at low doses via presynaptic dopamine receptor blockade, on negative symptoms of schizophrenia. Method. The study was designed as a parallel-group, double-blind, placebo-controlled trial. Patients had to fulfil DSM-III criteria for schizophrenia, Andreasen's criteria fo r negative schizophrenia, and to have a total score of at least 75 on the SANS; those treated with neuroleptics or antidepressants underwent a six-week placebo wash-out. One hundred and four in-patients were ra ndomly assigned to amisulpride 100 mg/d, amisulpride 300 mg/d, or plac ebo for six weeks; 85 patients completed the study. Results. Both amis ulpride doses were significantly more effective than placebo on the pr imary evaluation criterion (SANS total score, MANOVA P<0.02). No signi ficant changes were found in positive symptoms or in extrapyramidal sy mptoms. Conclusions. Negative symptoms can be improved by low doses of amisulpride, favouring the hypothesis of dopaminergic hypofunction as one of the causes of negative symptoms.