Tyrosine for depression: a double-blind trial

J Affect Disord. 1990 Jun;19(2):125-32. doi: 10.1016/0165-0327(90)90017-3.


We treated 65 outpatients with RDC major depression in a randomized, prospective, double-blind comparison of oral L-tyrosine, 100 mg/kg/day, imipramine, 2.5 mg/kg/day, or placebo for 4 weeks. Tyrosine increased and imipramine decreased 3-methoxy-4-hydroxyphenylglycol (MHPG) excretion significantly, but there was no evidence that tyrosine had antidepressant activity. The only side effect to achieve statistical significance was greater dry mouth with imipramine. MHPG excretion and plasma amino acid concentrations failed to predict or correlate with clinical improvement.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / psychology
  • Double-Blind Method
  • Female
  • Humans
  • Imipramine / therapeutic use
  • Male
  • Methoxyhydroxyphenylglycol / urine
  • Middle Aged
  • Prospective Studies
  • Psychiatric Status Rating Scales
  • Randomized Controlled Trials as Topic
  • Tyrosine / therapeutic use*


  • Tyrosine
  • Methoxyhydroxyphenylglycol
  • Imipramine