Neuroleptic bioavailability, psychosocial factors, and clinical status: a 1-year study of schizophrenic outpatients after dose reduction.

Serum neuroleptic levels, prolactin levels, and clinical state were assessed for 1 year in 29 schizophrenic outpatients whose clinically determined neuroleptic dose had been reduced by 50%. Fifty-five percent of the subjects remained stable. Neuroleptic dose did not differ between relapsed and stable patients. Serum prolactin (PRL) assessed 2 weeks after dose reduction and mean PRL after reduction were significantly lower among relapsers. Serum neuroleptic levels were significantly lower for relapsers in patients on haloperidol. Among relapsers, there were no serum PRL or neuroleptic level differences between stable periods and the relapse episode. Among patients with relatively low neuroleptic bioavailability, relapsers reported lower levels of social activity and had social networks that were less enjoyable, more aversive, and less helpful than those of stable patients.