Treatment of attention deficit disorder with DL-phenylalanine

Psychiatry Res. 1985 Sep;16(1):21-6. doi: 10.1016/0165-1781(85)90024-1.


Nineteen patients meeting the criteria for attention deficit disorder, residual type (adult hyperactivity), were given a 2-week double-blind crossover of DL-phenylalanine versus placebo. Thirteen subjects completed the study; the mean global rating of improvement approached significance as compared with placebo. A significant improvement was noted on mood and mood lability. The phenylalanine responders were then continued on open drug, but lost all positive benefits within 3 months. A later open trial of L-phenylalanine produced no clinical effect.

Publication types

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

MeSH terms

  • Adult
  • Attention Deficit Disorder with Hyperactivity / drug therapy*
  • Clinical Trials as Topic
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Drug Tolerance
  • Female
  • Humans
  • Male
  • Phenylalanine / administration & dosage
  • Phenylalanine / therapeutic use*
  • Time Factors


  • Phenylalanine