Jh. Hughes et al., Effects of acute tryptophan depletion on mood and suicidal ideation in bipolar patients symptomatically stable on lithium, BR J PSYCHI, 177, 2000, pp. 447-451
Background Previous studies suggest that brain serotonin neurotransmission
may mediate the actions of lithium carbonate. Acute tryptophan depletion re
duces brain serotonin and allows the study of this neurotransmitter in pati
ent groups.
Aims To examine the effects of acute tryptophan depletion on mood and suici
dal ideation in bipolar patients who were symptomatically stable on lithium
.
Method Nineteen subjects satisfying DSM - IV criteria for bipolar I disorde
r participated in a within-subject, double-blind, placebo-controlled random
-order crossover study. Symptoms were evaluated following acute tryptophan
depletion. which was induced by a 100 g amino acid drink following an overn
ight fast.
Results Plasma tryptophan fell significantly after the depleting drink, but
not after the control drink (P < 0.05, paired t-test, mean reduction 83%).
No significant changes in mood or suicidality scores were recorded after a
cute tryptophan depletion.
Conclusions Acute tryptophan depletion does not reverse lithium's effects o
n mood and suicidality in bipolar disorder.
Declaration of interest Funded by the Theodore and Vada Stanley Foundation.