Are There Secondary Effects on Marijuana Use From Brief Alcohol Interventions for College Students?

Abstract

ABSTRACT. Objective: This study examined whether brief motivational interventions (BMIs) designed for reducing heavy drinking among college students have secondary effects on reducing marijuana use. Method: The data came from Project INTEGRATE, which combined data from 24 independent trials of BMIs and other individual-focused interventions designed to reduce heavy drinking and related problems among college students. We analyzed data from 10 samples across nine studies that used random assignment of participants into either a BMI or a control group and assessed marijuana use outcomes (N = 6,768; 41.5% men; 73.2% White; 57.7% first-year students; 19.2% current marijuana users at baseline). We derived three marijuana use groups within studies by cross-tabulating baseline and follow-up data: Nonusers, Reducers, and Stayers/Increasers. Results: Peto's one-step odds ratio analyses for meta-analysis revealed no significant intervention effects on marijuana use at either short-term (1-3 month) or long-term (6-12 month) follow-up. Subsequent exploratory analyses showed that those who reduced drinking were more likely to be a marijuana Reducer or Nonuser, compared with a Stayer/Increaser, at both follow-ups. Conclusions: The BMIs to reduce heavy drinking evaluated in this study did not reduce marijuana use. However, our exploratory results suggest that if we can develop interventions for college students that effectively reduce drinking, we may also reduce their marijuana use. Furthermore, as recreational use of marijuana becomes legal or decriminalized and marijuana becomes more readily available, it may be necessary to develop interventions specifically targeting marijuana use among college students. (J.

Co-use of Alcohol and Cannabis: A Review

“…With the intervention research on co-use of alcohol and cannabis lacking, some studies have begun to examine the secondary effects of alcohol-specific interventions on changes in cannabis use. A recent meta-analysis indicated that alcohol BMIs may not facilitate changes in cannabis use among college students [96]; instead, regardless of treatment condition, college students who successfully reduced their drinking at short-and long-term follow-ups were more likely to be non-users of cannabis or reduce their cannabis use at follow-up. This complementary relationship between cannabis and alcohol use is also supported by research indicating that the risk factors for initiation and maintenance of problematic use are similar across substances [97], and together suggest that individuals and interventions that successfully reduce alcohol consumption may lead to secondary changes in cannabis use.…”

“…From a clinical standpoint, it appears co-use of cannabis and alcohol may negatively impact the successful intervention of both substances, yet there are few studies examining the development and evaluation of interventions on reducing their co-use. Motivational and brief interventions appear promising, but this may vary depending on population [28,79,96]. An added clinical concern is the association between co-use and psychiatric comorbidity.…”

Are Co‐users of Alcohol and Marijuana More Willing to Experience Consequences From Drinking? A Longitudinal Examination Among First‐Year College Students

“…Our findings may have important intervention implications for targeting couse of alcohol and marijuana in light of findings that BMIs designed to reduce heavy drinking did not also reduce marijuana use (White et al., ) and attempts to reduce couse of alcohol and marijuana have not been efficacious (Stein et al., ). Specifically, many empirically supported BMIs target risky drinking behavior by discussing potential acute and severe negative consequences that can occur when engaging in heavy drinking as a means of motivating individuals to drink less.…”

“…While brief motivational interventions (BMIs) focused on marijuana use have shown promising effects in reducing use among adolescents and young adults (e.g., Bernstein et al., ; Lee et al., ; Martin et al., ), BMIs have been found to have modest effects on reducing alcohol use and reducing marijuana use (Hides et al., ; Magill et al., ; Woolard et al., ). A meta‐analysis of BMIs targeting heavy drinking among college students indicated that BMIs did not also reduce marijuana use at short‐ or long‐term follow‐ups (White et al., ). Moreover, a recent BMI developed for heavy‐drinking young adults who also use marijuana was unsuccessful in reducing heavy drinking, marijuana use, or couse days relative to the control condition (Stein et al., ).…”

A developmental‐based motivational intervention to reduce alcohol and marijuana use among non‐treatment‐seeking young adults: a randomized controlled trial

“…Among dual users—who are at heightened risk for psychosocial and mental health effects —brief motivational interventions have modestly reduced both alcohol and marijuana use in adult populations . A review of BMIs for alcohol among college students looking for secondary effects on marijuana use found no direct intervention effects on marijuana, but did find that as alcohol use decreased, marijuana use decreased as well . In summary, in both hazardous alcohol use and marijuana brief intervention studies, the effect size is modest, treatment effects fade in the months following intervention, and the optimal timing and number of community‐based booster sessions remain open to further research.…”