Factors influencing prolactin release induced by electroconvulsive therapy.

Electroconvulsions have been reported to induce rapid elevations of serum prolactin (PRL) levels. To further evaluate factors involved in the hormonal release an extended study was performed. Blood samples for determination of PRL were withdrawn from depressed patients 5 min before and 15 min after administration of electroconvulsions. Significant elevations of PRL levels were found in 35 of 37 patients. Increase in PRl levels was significantly correlated to duration of seizures but not to duration of the electric stimulation. The hormonal response to electroconvulsions was diminished with age. Patients on lithium medication had significantly more pronounced rises of PRL levels than patients treated with other psychotropic drugs and otherwise untreated patients. The results indicate that the elevation in PRL levels is a biochemical marker of the seizure activity during electroconvulsive therapy.