L-Tryptophan demonstrates an anti-depressant effect in seasonal affective disorder (SAD). - GreenMedInfo Summary
The effect of L-tryptophan on seasonal affective disorder.
Water Res. 2002 Sep;36(15):3821-33. PMID: 2182615
Serotonin has been implicated in the etiology of seasonal affective disorder (SAD). The authors compared the effect of the serotonergic precursor L-tryptophan, placebo, and artificial evening light on 13 SAD sufferers. L-Tryptophan and light were associated with greater improvement than was placebo, but the antidepressant effects of L-tryptophan and light were not significantly different.