BACKGROUND: Previous work has suggested that acute depletion of the serotonin (5-HT) precursor tryptophan (TRP) causes transient compensatory changes in the 5-HT system that might be exploited for their antidepressant effects. In this study, neuroendocrine and mood responses to intravenous (i.v.) infusion of TRP were examined in order to evaluate central 5-HT function in depressed patients undergoing acute TRP depletion. METHODS:Thirty-eight drug-free patients with DSM-III-R major depression participated. Each patient underwent two randomized, double-blind TRP depletion tests, one sham and one active. At the estimated time of maximum TRP depletion, each patient received an i.v. infusion of TRP 100 mg/kg. Blood was obtained for serum cortisol, prolactin, and growth hormone. Mood was assessed using standardized rating scales. RESULTS: The cortisol response to i.v. TRP was significantly greater during TRP depletion than during sham depletion. Depressive symptoms showed a tendency to decrease after i.v. TRP following active, but not sham, TRP depletion. CONCLUSIONS: These findings are consistent with the present hypothesis and previous evidence that acute TRP depletion in drug-free depressed patients induces compensatory upregulation of postsynaptic 5-HT receptors. These changes are insufficient to serve as a means of effecting clinical improvement, but suggest that the antidepressant properties of rapid, marked manipulations of 5-HT function warrant further study.
RCT Entities:
BACKGROUND: Previous work has suggested that acute depletion of the serotonin (5-HT) precursor tryptophan (TRP) causes transient compensatory changes in the 5-HT system that might be exploited for their antidepressant effects. In this study, neuroendocrine and mood responses to intravenous (i.v.) infusion of TRP were examined in order to evaluate central 5-HT function in depressedpatients undergoing acute TRP depletion. METHODS: Thirty-eight drug-free patients with DSM-III-R major depression participated. Each patient underwent two randomized, double-blind TRP depletion tests, one sham and one active. At the estimated time of maximum TRP depletion, each patient received an i.v. infusion of TRP 100 mg/kg. Blood was obtained for serum cortisol, prolactin, and growth hormone. Mood was assessed using standardized rating scales. RESULTS: The cortisol response to i.v. TRP was significantly greater during TRP depletion than during sham depletion. Depressive symptoms showed a tendency to decrease after i.v. TRP following active, but not sham, TRP depletion. CONCLUSIONS: These findings are consistent with the present hypothesis and previous evidence that acute TRP depletion in drug-free depressedpatients induces compensatory upregulation of postsynaptic 5-HT receptors. These changes are insufficient to serve as a means of effecting clinical improvement, but suggest that the antidepressant properties of rapid, marked manipulations of 5-HT function warrant further study.
Authors: Beverly H Brummett; Michael A Babyak; Cynthia M Kuhn; Ilene C Siegler; Redford B Williams Journal: Biol Psychol Date: 2014-10-20 Impact factor: 3.251
Authors: Beverly H Brummett; Stephen H Boyle; Ilene C Siegler; Cynthia M Kuhn; Richard S Surwit; Melanie E Garrett; Ann Collins; Allison Ashley-Koch; Redford B Williams Journal: Biol Psychol Date: 2008-07-01 Impact factor: 3.251
Authors: Stephen H Boyle; Beverly H Brummett; Cynthia M Kuhn; John C Barefoot; Ilene C Siegler; Redford B Williams; Anastasia Georgiades Journal: Psychosom Med Date: 2019-01 Impact factor: 4.312