An experimental comparison of Pycnogenol and methylphenidate in adults with Attention-Deficit/Hyperactivity Disorder (ADHD)

J Atten Disord. 2002 Sep;6(2):49-60. doi: 10.1177/108705470200600201.


Twenty-four adults (24 to 53 years old) with Attention-Deficit/Hyperactivity Disorder (ADHD), Combined Type, were studied in a double-blind, placebo-controlled, crossover study of Pycnogenol and methylphenidate. Pycnogenol is an antioxidant derived from the bark of the French maritime pine tree. Methylphenidate is a standard pharmaceutical intervention for ADHD. Anecdotal reports suggest that Pycnogenol improves concentration in adults with ADHD without adverse side effects. Participants received Pycnogenol, methylphenidate, and placebo, each for three weeks, in a randomized and counterbalanced order. Although ADHD symptoms improved during treatment, neither methylphenidate nor Pycnogenol outperformed the placebo control, as measured by self-report rating scales, rating scales completed by the individual's significant other, and a computerized continuous performance test. The conservative dosage levels and relatively brief length of treatment may have contributed to the absence of significant differences among treatment conditions. Implications for future research are noted.

Publication types

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

MeSH terms

  • Adjuvants, Immunologic / therapeutic use*
  • Adult
  • Attention Deficit Disorder with Hyperactivity / diagnosis
  • Attention Deficit Disorder with Hyperactivity / drug therapy*
  • Central Nervous System Stimulants / therapeutic use*
  • Flavonoids / therapeutic use*
  • Humans
  • Male
  • Methylphenidate / therapeutic use*
  • Middle Aged
  • Plant Extracts
  • Severity of Illness Index


  • Adjuvants, Immunologic
  • Central Nervous System Stimulants
  • Flavonoids
  • Plant Extracts
  • Methylphenidate
  • pycnogenols