[Pharmacologic approach to negative symptoms in schizophrenia]

Various pharmacologic agents have been reported to be effective in treating negative symptoms of schizophrenia. European schools of psychiatry and especially the French one assumed the opinion that part of negative symptoms of schizophrenia do respond to neuroleptics. In light of effects of reserpine and some phenothiazines on negative schizophrenia, various pharmacologic agents have been studied focusing on these properties. Various papers devoted to this question concluded that some drugs, particularly neuroleptics, can be considered as disinhibitors: phenothiazines (thiotixene, trifluoperazine, fluphenazine, pipotiazine), butyrophenones (trifluperidol, risperidone), diphenylbutylpiperidines (pimozide) and benzamides (sulpiride, amisulpiride). Major part of controlled studies concluded to the better efficacy of low doses of such drugs on negative symptoms, while high doses are almost inefficient. Some studies concluded in the activity of clozapine on negative symptoms of schizophrenic patients. To answer the question whether negative symptoms of schizophrenia are improved concomitantly or independently of improvement in positive symptoms or of decrease in extrapyramidal side effects and/or depressive symptoms, the authors prospectively followed up for 30 months, 13 DSM-IV resistant schizophrenics. Symptoms were assessed by means of 18 item Brief Psychiatric Rating Scale, Positive and Negative Syndrome Scale and Extrapyramidal Symptom Rating Scale (ESRS). Improvement in negative symptoms was significantly correlated to improvement in positive ones and to scores in ESRS. Many open studies concerning anti-depressants and other drugs have been published; however controlled studies are necessary to confirm these data.