Tryptophan Depletion, Serotonin, and Depression: Where Do We Stand?

Tryptophan depletion is a widely used paradigm to study serotonin system-related mechanisms in the pathophysiology and treatment of depression. There is convincing evidence that tryptophan depletion primarily and selectively affects serotonergic transmission. The behavioral data in healthy controls with and without genetic risk for depression, and in patient populations during the symptomatic phase of depression and when being remitted, suggest a trait abnormality of serotonin function in depression and that antidepressants may compensate for the underlying deficit. Tryptophan depletion may be a useful tool to create more integrative models for the pathophysiology of depression that take into account…