Acute yohimbine increases laboratory-measured impulsivity in normal subjects

Biol Psychiatry. 2005 May 15;57(10):1209-11. doi: 10.1016/j.biopsych.2005.02.007.


Background: State-dependent changes in impulsivity may be related to norepinephrine. To examine possible relationships between norepinephrine and acute changes in impulsivity, we measured effects of yohimbine, which increases norepinephrine release by blocking alpha-2 noradrenergic receptors, on laboratory-measured impulsivity in healthy subjects without psychiatric or substance-use disorders.

Methods: Impulsivity was assessed using the Immediate and Delayed Memory Tasks (IMT-DMT), derived from the Continuous Performance Test, before and after placebo or two doses of yohimbine, given 4 days apart. Blood pressure was monitored, and psychiatric symptoms were measured using self-rated visual analog scales.

Results: Yohimbine was associated with a dose-related increase in impulsive IMT commission errors, with an increase of > 50% relative to baseline at the higher dose. The activation factor of the Internal State Scale was increased at the same dose.

Conclusions: These results are consistent with increased impulsivity in normal subjects given yohimbine, possibly related to increased norepinephrine.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adrenergic alpha-Antagonists / pharmacology*
  • Adult
  • Arousal / drug effects
  • Blood Pressure / drug effects
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Humans
  • Impulsive Behavior / chemically induced*
  • Impulsive Behavior / psychology*
  • Male
  • Memory / drug effects
  • Memory, Short-Term / drug effects
  • Norepinephrine / physiology
  • Psychomotor Performance / drug effects
  • Psychomotor Performance / physiology
  • Yohimbine / pharmacology*


  • Adrenergic alpha-Antagonists
  • Yohimbine
  • Norepinephrine