Co-occurring marijuana use is associated with medication nonadherence and nonplanning impulsivity in young adult heavy drinkers

Addict Behav. 2012 Apr;37(4):420-6. doi: 10.1016/j.addbeh.2011.11.036. Epub 2011 Dec 3.


Few studies have examined the co-occurrence of alcohol and marijuana use in clinical samples of young adults. The present study investigated whether co-occurring marijuana use is associated with characteristics indicative of a high level of risk in young adult heavy drinkers. Individuals between the ages of 18 and 25 years (N=122) participated in an ongoing 8-week randomized clinical trial that tested the efficacy of placebo-controlled naltrexone plus brief individual counseling to reduce heavy drinking. At intake participants completed self-report assessments on alcohol consumption, alcohol-related negative consequences, motivation to reduce drinking, trait impulsivity, expectancies for alcohol-induced disinhibition, use of cigarettes, and history of medication nonadherence. In univariate tests heavy drinkers with and without co-occurring marijuana use did not differ on alcohol consumption, most alcohol-related negative consequences, and motivation to reduce drinking. In multivariate tests controlling for demographic characteristics, co-occurring heavy alcohol and marijuana use was significantly associated with nonplanning impulsivity (β=2.95) and a history of both unintentional (adjusted odds ratio [aOR]=3.30) and purposeful (aOR=3.98) nonadherence to medication. Findings suggest that young adult heavy drinkers with co-occurring marijuana use exhibit a high-risk clinical profile and may benefit from interventions that increase adherence to medications.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Alcohol Deterrents / therapeutic use
  • Alcohol-Related Disorders / complications
  • Alcohol-Related Disorders / psychology*
  • Alcohol-Related Disorders / rehabilitation
  • Analysis of Variance
  • Combined Modality Therapy
  • Counseling / methods
  • Female
  • Humans
  • Impulsive Behavior / psychology*
  • Male
  • Marijuana Smoking / psychology*
  • Medication Adherence / psychology*
  • Motivation
  • Naltrexone / therapeutic use
  • Patient Satisfaction
  • Psychotherapy / methods
  • Risk Factors
  • Young Adult


  • Alcohol Deterrents
  • Naltrexone