Serum neuroleptic activity, prolactin, and tardive dyskinesia in schizophrenic outpatients.

The authors measured serum neuroleptic activity and serum prolactin levels in 26 schizophrenic outpatients on prolonged neuroleptic therapy. Of the 24 patients, 11 had moderate to severe tardive dyskinesia, as assessed by the Abnormal Involuntary Movement Scale (AIMS). AIMS scores were positively correlated with age, duration of illness, and negative schizophrenic symptoms, but not with variables of neuroleptic exposure, current serum levels of neuroleptic activity, or serum prolactin levels. Neuroleptic activity and prolactin levels were positively correlated, and both variables also correlated with the current daily dose of neuroleptics.