TRH STIMULATION TEST AS A PREDICTOR OF ACUTE AND LONG-TERM ANTIDEPRESSANT RESPONSE IN MAJOR DEPRESSION

We assessed the prognostic utility of the TRH stimulation test by exam ining (a) the relationship between pre-treatment Delta TSH and acute r esponse to fluoxetine treatment, and (b) the relationship between the change in Delta TSH (Delta Delta TSH value) after repeated TRH testing at 6 weeks of fluoxetine treatment and long-term outcome during maint enance fluoxetine or placebo therapy. 43 MDD patients were studied wit h sequential TRH tests at 6-week intervals. Fluoxetine 'responders' we re defined as patients with a Hamilton Depression Rating Scale score l ess than or equal to 7 by week 9 of treatment and who remained in remi ssion at least 3 additional weeks. These subjects were then randomized to one of four fluoxetine/placebo treatment groups and long-term outc ome assessed, Overall, there was no difference in the mean pre-treatme nt Delta TSH values between acute fluoxetine responders and nonrespond ers. Moreover, we observed similar Delta Delta TSH values in patients who maintained long-term remission compared to those who relapsed duri ng maintenance with either fluoxetine or placebo. In contrast to prior reports of an higher Delta Delta TSH value in long-term remitters, th e present observation of similar mean Delta Delta TSH values patients with long-term remission compared to those who relapsed suggest a limi ted prognostic utility for the TRH stimulation test in MDD.