5-Hydroxy-indolacetic-acid (5-HIAA) serum levels in depressive patients and ECT.

In 31 drug and ECT naive melancholic patients, serum levels of the major metabolite of serotonin 5-hydroxy-indolacetic-acid (5-HIAA) were estimated in the first and third ECT of a course. Plasma samples were taken before ECT and 1, 60 and 120 min thereafter. The estimations were done by a new high performance liquid chromatography method (HPLC). After the seizure, a statistically significant decrease of 5-HIAA serum levels was observed over both ECTs. There was a significant increase in 5-HIAA serum levels from the first to the third ECT. ECT was found to influence serotonin turnover. It might be interpreted that ECT improves serotonergic responsiveness and neurotransmission. There was no significant correlation between 5-HIAA levels and gender, or age of the patients, or seizure duration. Furthermore, the severity of depression and treatment response did not correlate with certain 5-HIAA serum level patterns.