Relationship of psychotic symptoms to haloperidol-stimulated prolactin release.

Prolactin (PRL) response to a single dose of intravenous haloperidol (0.5 mg) was measured as a marker of tuberoinfundibular dopamine (TIDA) activity in 24 neuroleptic-free, male, psychotic patients. The PRL responses were then correlated with psychotic symptoms measured with Andreasen's Scales for the Assessment of Positive and Negative Symptoms (SAPS, SANS). Correlation analyses revealed a significant inverse relationship between PRL response and the severity of delusional symptoms. There was no significant correlation between the symptoms of hallucinations, formal thought disorder, or global negative symptoms and PRL response to haloperidol, nor were there any significant correlations between basal PRL and symptom severity. These results suggest that among the positive and negative symptoms associated with psychoses, only delusions may be associated with TIDA overactivity.