Beneficial effect of the addition of the 5-HT 2A/2C and α2 antagonist mianserin to ongoing haloperidol treatment in drug-resistant chronically hospitalized schizophrenic patients

Atypical neuroleptics that block serotonin 2A (5-HT 2A) and dopamine 2 (D2) receptors have been shown to possess efficacious antipsychotic activity. We assessed the efficacy of the addition of the 5-HT 2A/2C and alpha2 antagonist mianserin to ongoing haloperidol treatment in chronically hospitalized (> 10 years) drug-resistant schizophrenic patients (N = 12). The patients were assessed at baseline and every three months for one year with the Brief Psychiatric Rating Scale and the Clinical Global Impression. Results showed a significant (but < 10%) improvement in the core symptoms of schizophrenia; however, only the reduction (by 43%) in anxiety was clinically relevant (P < 0.0001). The beneficial effect of mianserin may be related to the combined blockade of 5-HT 2A and histamine (H1) receptors.