The neurobiology of tryptophan depletion in depression: effects of intravenous tryptophan infusion.
Biol Psychiatry
; 43(5): 339-47, 1998 Mar 01.
Article
in En
| MEDLINE
| ID: mdl-9513749
ABSTRACT
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.
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Database:
MEDLINE
Main subject:
Tryptophan
/
Affect
/
Depressive Disorder
/
Neurosecretory Systems
Type of study:
Clinical_trials
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Year:
1998
Type:
Article