Lithium, but not valproate, reduces impulsive choice in the delay-discounting task in mice

Neuropsychopharmacology. 2013 Sep;38(10):1937-44. doi: 10.1038/npp.2013.89. Epub 2013 Apr 12.


Both lithium and valproate are well-established treatments for bipolar disorder. Studies have also found that lithium is effective at reducing suicidal behaviors in patients with mood disorders. Impulsivity is a validated endophenotype of both bipolar disorder and suicidal behavior. We assessed effects of treatment with lithium or valproate on cognitive impulsivity in selectively bred mice previously shown to manifest relatively high levels of cognitive impulsivity. Mice were trained in the delay-discounting paradigm, a measure of cognitive impulsivity reflecting a behavioral bias towards immediacy, and then treated with lithium, valproate, or control chow. After 3 weeks of drug treatment, mice were tested at various delays to a large, delayed reward. Drug treatment continued during this time. Lithium reduced impulsivity, whereas valproate had no effect on choice behavior. Both drugs increased the number of choice trials and reinforcer intake, but effects on choice behavior did not depend on these motivational changes. To our knowledge, this is the first study demonstrating lithium's effects to reduce cognitive impulsivity. Future studies may focus on the ability of putative pharmacotherapies for patients at risk for bipolar disorder or suicide to modify the impulsive choice dimension of this diseases.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antimanic Agents / pharmacology
  • Antimanic Agents / therapeutic use
  • Choice Behavior / drug effects*
  • Conditioning, Operant / drug effects
  • Female
  • Impulsive Behavior / drug therapy*
  • Lithium Chloride / pharmacology*
  • Lithium Chloride / therapeutic use*
  • Male
  • Mice
  • Mice, Inbred Strains
  • Valproic Acid / pharmacology*
  • Valproic Acid / therapeutic use*


  • Antimanic Agents
  • Valproic Acid
  • Lithium Chloride