Zinc in attention-deficit/hyperactivity disorder

J Child Adolesc Psychopharmacol. 2005 Aug;15(4):619-27. doi: 10.1089/cap.2005.15.619.


Objective: The aim of this study was to review the published evidence for a role of zinc nutrition in attention-deficit/hyperactivity disorder (ADHD).

Method: A computer literature search was supplemented by the authors' knowledge.

Results: Numerous controlled studies report cross-sectional evidence of lower zinc tissue levels (serum, red cells, hair, urine, nails) in children who have ADHD, compared to normal controls and population norms. A few studies show correlations of zinc level with either clinical severity or a change thereof in response to stimulant or chemical challenge. Two placebo-controlled trials--one of zinc monotherapy, the other of zinc supplementation of methylphenidate--reported significant benefit. However, diagnostic procedures and sample representativeness were often not clear, and most such reports have come from countries and cultures with different diets and/or socioeconomic realities than are found in the United States (only one American sample in nine published reports). In particular, both positive clinical trials of zinc supplementation came from the Mid-East (Turkey and Iran), an area with suspected endemic zinc deficiency. The largest of these trials used zinc doses above the recommended upper tolerable limit and had a 2 in 3 dropout rate.

Conclusion: It is not clear how well the accumulating evidence for a possible role of zinc in ADHD applies to middle-class American children. However, the evidence appears strong enough to warrant further controlled study in well-diagnosed samples representative of the socioeconomic spectrum. Hypothesis-testing clinical trials are needed of this potential treatment that, if found effective, might become a relatively safe, cheap substitute for, or adjunct to, current treatments in some patients. At present, it should remain an investigational treatment.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Attention Deficit Disorder with Hyperactivity / drug therapy
  • Attention Deficit Disorder with Hyperactivity / metabolism*
  • Attention Deficit Disorder with Hyperactivity / psychology
  • Brain / physiology
  • Child
  • Clinical Trials as Topic
  • Humans
  • Zinc / deficiency
  • Zinc / metabolism
  • Zinc / physiology*
  • Zinc / therapeutic use


  • Zinc