Prolactin response to submaximal stimulation by TRH in nonaffective psychoses.

Nonaffective psychotic symptoms are heterogeneous and probably caused by mixed biopathology. A preliminary investigative tool to study pituitary dopamine activity, the prolactin response to submaximal stimulation by thyrotropin-releasing hormone (TRH) (mini-TRH test) was correlated in 20 subjects with nonaffective psychoses to positive psychotic symptoms as assessed by the Comprehensive Psychiatric Rating Scale psychosis subscale. A significant positive correlation was observed between the response and ratings of nonparanoid symptoms, especially nonparanoid delusions and disrupted thoughts. Because, in addition to pituitary dopamine activity, there is evidence to suggest that the response reflects extrapituitary dopamine activity as well, the results extend the evidence that nonparanoid acute productive psychotic symptoms may be associated with hypoactivity rather than with hyperactivity of brain dopaminergic systems.