Can Cannabis Be Considered a Substitute Medication for Alcohol?

Meenakshi Sabina Subbaraman

Disclosures

Alcohol Alcohol. 2014;49(3):292-298. 

In This Article

Discussion

Summary of Criteria

All criteria except #6 appear either satisfied or partially satisfied ( Table 1 ). Besides the overall paucity of literature on the topic, major gaps include prior focus on medical cannabis patients and retrospective designs. Furthermore, studies that support substitution have not assessed subsequent harms, problems or related issues like health economic benefits or quality of life. Most importantly, no study has prospectively examined, (a) whether individuals with alcohol use disorders can effectively use cannabis to help reduce drinking and (b) longer term problems and health economic outcomes among those who substitute.

Cannabis and Active Substance Abuse Treatment

An exploratory study of medical cannabis users in substance abuse treatment suggested that medical cannabis use does not hinder drug treatment participation or adversely affect treatment outcomes (Swartz, 2010). In fact, results imply that those using medical cannabis may have had better treatment completion, employment and alcohol use outcomes compared with their non-medical cannabis using counterparts.

Similarly, Raby et al. (2009) showed that cannabis use may enhance treatment retention and improve outcomes for opiate-dependent individuals. Intermittent cannabis use predicted greater treatment retention and adherence to naltrexone pill taking. The authors speculate that cannabis may improve tolerability of naltrexone, perhaps because naltrexone enhanced the intoxicating effects of cannabis; this may have implications for naltrexone compliance among alcohol-dependent individuals, even though the study only included opiate-dependent individuals who did not drink much alcohol (Raby et al., 2009).

Legalization Movements in USA

Regardless of cannabis's candidacy as a substitute, the recent movements toward cannabis legalization in the USA make substance substitution especially relevant. A 2005 study of college students reported that they might reduce their drinking if cannabis were legalized, especially among daily drinkers and those who drank spirits (Clements and Daryal, 2005). A study of alcohol and cannabis policy effects on drug use similarly suggested lower alcohol use in states, where cannabis was decriminalized (Saffer and Chaloupka, 1999). Furthermore, when the minimum legal drinking age was raised in the 1980s, cannabis consumption went up among American students in 43 states (DiNardo and Lemieux, 2001). A similar substitution effect has been observed in high school students (Alter et al., 2006). Interestingly, Alter et al. also found that students who reported no alcohol use were more likely to report cannabis use. Although Alter et al. (2006) focus on perceived access to cannabis and perceptions of related harms, the findings may imply that cannabis can substitute for alcohol among individuals who choose to completely abstain from alcohol.

Next Steps

The mixed evidence for all criteria besides #2 and #5 highlight areas for future research. For example, future studies should prospectively assess both alcohol-related (Criteria #1 and #4) and health economic (Criterion #7) outcomes for those who substitute and those who do not; although a randomized control trial is ideal, this involves substantial practical barriers due to cannabis' legal status. One alternative design would be to follow those in treatment and compare outcomes for those who substitute versus those do not. Another would be to randomly assign individuals with AUD who also use cannabis to quit using cannabis and compare alcohol use outcomes to those not assigned to quit cannabis. In addition to longitudinal assessments, future studies should gather data regarding THC content and cannabis strains consumed by cannabis users as these factors likely impact cannabis' efficacy as a substitute.

While more research and improved study designs are needed to better identify the extent and impact of cannabis substitution on those affected by AUD, cannabis does appear to be a potential substitute for alcohol. Perhaps more importantly, cannabis is both safer and potentially less addictive than benzodiazepines and other pharmaceuticals that have been evaluated as substitutes for alcohol.

processing....