A double-blind, placebo-controlled study published in Acta Psychiatrica Scandinavica (1979;59:395–414) compared three treatment approaches in 25 adults aged 18–60 with severe depression. Participants were randomized into three groups:
-
Tryptophan + nicotinamide
-
Imipramine (a tricyclic antidepressant)
-
Imipramine + tryptophan + nicotinamide
The researchers measured blood tryptophan levels and evaluated how those levels correlated with treatment response.
Study Findings
-
In the group receiving tryptophan + nicotinamide, a favorable response to therapy correlated with rising blood tryptophan levels.
-
In the group receiving imipramine + supplements, a negative correlation was seen—suggesting that when tryptophan levels became too high, therapeutic benefits diminished.
Conclusions
The authors concluded that:
-
Tryptophan + nicotinamide alone may be as effective as imipramine for some patients.
-
Lower doses of these supplements may enhance the effect of imipramine, while higher doses may interfere with it.
This early trial highlights the importance of dosage balance when combining amino-acid precursors with antidepressant medications, and suggests a potential nutrient-drug interaction worth further study.
Educational only — not medical advice.
