Immediate serum growth hormone decrease as a potential index of dopamine-related response to electroconvulsive therapy in schizophrenic patients

Objectives: The objective of this study was to investigate the immediate response of the dopamine-regulated growth hormone (GH) to electroconvulsive therapy (ECT) in schizophrenic patients and the changes in the serum GH levels throughout the consecutive sessions of the therapeutic ECT course. Methods: Serum GH levels were measured in a sample of 11 men with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, who were administered a course of 8 bilateral ECT treatments. Measurements were performed 5 minutes before ECT, during ECT, 15 minutes after an ECT session, and 30 minutes after an ECT session during the first, fourth, and eighth ECT sessions. Results: At both the fourth and the eighth ECT sessions, a significant decrease in GH levels 15 and 30 minutes after ECT was observed compared with the baseline values. No change in baseline serum GH levels was observed either during or at the end of the treatment. Clinical improvement was indicated by a significant reduction in the total score, negative subscale score, and positive subscale score of the Positive and Negative Syndrome Scale. Conclusions: The results are consistent with the potential role of immediate serum GH changes as an index of potential dopamine-mediated response to ECT. It can be assumed that GH reduction may be partially related to an antidopaminergic action of ECT, but further research is still needed to better evaluate the correlation of the dopamine system instability during the course of the illness with the previously mentioned immediate treatment response. Also, the role of other neurotransmitters in the regulation of GH production and ECT response must be taken into account for the purpose of an overall evaluation of the results and of their potential clinical implications.