Cognitive Impairment in Cocaine Users Is Drug-Induced but Partially Reversible: Evidence From a Longitudinal Study

Neuropsychopharmacology. 2014 Aug;39(9):2200-10. doi: 10.1038/npp.2014.71. Epub 2014 Mar 21.

Abstract

Cocaine users consistently display cognitive impairments. However, it is still unknown whether these impairments are cocaine-induced and if they are reversible. Therefore, we examined the relation between changing intensity of cocaine use and the development of cognitive functioning within 1 year. The present data were collected as part of the longitudinal Zurich Cocaine Cognition Study (ZuCo(2)St). Forty-eight psychostimulant-naive controls and 57 cocaine users (19 with increased, 19 with decreased, and 19 with unchanged cocaine use) were eligible for analysis. At baseline and after a 1-year follow-up, cognitive performance was measured by a global cognitive index and four neuropsychological domains (attention, working memory, declarative memory, and executive functions), calculated from 13 parameters of a broad neuropsychological test battery. Intensity of cocaine use was objectively determined by quantitative 6-month hair toxicology at both test sessions. Substantially increased cocaine use within 1 year (mean +297%) was associated with reduced cognitive performance primarily in working memory. By contrast, decreased cocaine use (-72%) was linked to small cognitive improvements in all four domains. Importantly, users who ceased taking cocaine seemed to recover completely, attaining a cognitive performance level similar to that of the control group. However, recovery of working memory was correlated with age of onset of cocaine use-early-onset users showed hampered recovery. These longitudinal data suggest that cognitive impairment might be partially cocaine-induced but also reversible within 1 year, at least after moderate exposure. The reversibility indicates that neuroplastic adaptations underlie cognitive changes in cocaine users, which are potentially modifiable in psychotherapeutical or pharmacological interventions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • Central Nervous System Stimulants / administration & dosage
  • Central Nervous System Stimulants / adverse effects
  • Central Nervous System Stimulants / analysis
  • Cocaine / administration & dosage
  • Cocaine / adverse effects
  • Cocaine / analysis
  • Cocaine-Related Disorders / complications*
  • Cocaine-Related Disorders / physiopathology
  • Cocaine-Related Disorders / psychology*
  • Cognition / drug effects
  • Cognition / physiology
  • Cognition Disorders / chemically induced
  • Cognition Disorders / etiology*
  • Cognition Disorders / physiopathology
  • Cross-Sectional Studies
  • Female
  • Follow-Up Studies
  • Hair / chemistry
  • Humans
  • Longitudinal Studies
  • Male
  • Memory, Short-Term / drug effects
  • Memory, Short-Term / physiology
  • Neuropsychological Tests
  • Recovery of Function
  • Severity of Illness Index

Substances

  • Central Nervous System Stimulants
  • Cocaine