CHANGES IN SINGLE SYMPTOMS AND SEPARATE FACTORS OF THE SCHIZOPHRENIC-SYNDROME AFTER TREATMENT WITH RISPERIDONE OR HALOPERIDOL

Risperidone, a rather selective blocker of D-2 and 5-HT-2 receptors, w as, in the doses 1 mg, 4 mg, 8 mg, 12 mg and 16 mg a day, compared to the rather selective D-2 blocker haloperidol in the dose of 10 mg a da y, in 88 chronic schizophrenic patients. After one week placebo wash-o ut, the patients were randomly assigned to one of the six treatment gr oups and the study was performed as a double blind parallel-group stud y for 8 weeks. In the present analysis, a special emphasis has been la id on the effects on single symptoms and separate factors in the schiz ophrenic syndrome. Overall, risperidone in a dose of 4 mg a day was co mparable to haloperidol in a dose of 10 mg a day. Risperidone was foun d to have a curvilinear dose-response curve with an optimum effect of 4 mg day on the negative, anxious/depressive and cognitive factors and with an optimum effect of 8 mg day on the positive and excited factor s. While haloperidol had significant effects on the negative and anxio us/depressive factors, risperidone had significant effects on all five factors - the positive, the negative, the excited, the anxious/depres sive and the cognitive. The fact that the novel drug had significant e ffects on the cognitive factor might be of great importance as concern s the possibilities for rehabilitation of chronic schizophrenic patien ts.