Research Updates in Addiction: Cannabis and Alcohol

marijuana addictionCANNABIS

Vilazodone Not Effective for Cannabis Dependence

REVIEW OF: McRae-Clark AL et al. Vilazodone for cannabis dependence: A randomized, controlled pilot trial. The American Journal on Addictions 2016;25(1):69–75

STUDY TYPE: Randomized clinical trial

Effective pharmacological treatments for cannabis dependence have eluded the field of addiction psychiatry. It’s not, however, due to a lack of trying. Theoretical connections between cannabinoids and the serotonin system have spurred a number of studies looking at the usefulness of SSRIs and buspirone. Overall, the results have been uninspiring. Recognizing that past studies have focused on either the reuptake properties of SSRIs or the partial agonism of buspirone, researchers looked at the potential of vilazodone, a combined serotonin reuptake inhibitor and partial serotonin 1A agonist.

Seventy-six adults with a diagnosis of cannabis dependence were randomized to a flexible dosing schedule of up to 40 mg (average = 32 mg) of vilazodone (n=41) or placebo (n=35). Urine screens were used to measure the primary outcome of cannabis use at baseline and over the 8-week course of the study. The Marijuana Craving Questionnaire tracked cravings, and patients were asked to keep tabs on the amount of cannabis they used over the 8 weeks. Both groups received three motivational enhancement sessions and were offered nominal financial incentives to increase engagement and compliance with treatment.

Did the combined serotonergic properties of vilazodone make a difference? Unfortunately not. Vilazodone fared no better than placebo with regard to cannabis use. Although the overall amount of cannabis use declined, it dropped equally in both groups. The vilazodone group smoked marijuana an average of 10 times per week, and the placebo group used an average of 9.9 times per week. A slight drop in cravings was noted for men in the vilazodone group, but not women. Interestingly, gender seems to have played a role in the level of cannabis use, as men racked up more overall negative urine screens than the women. This is consistent with previous research showing that women have more difficulty achieving cannabis abstinence (Cooper ZD and Haney M, Drug Alcohol Depend 2014;136:85–91) and report greater withdrawal symptoms (Copersino et al, Am J Drug Alcohol Abuse 2010;36:311–319).

CATR’S TAKE: It’s difficult to put a lot of faith into the results. Only 34% (14/41) of those originally assigned to the vilazodone group and 49% (17/35) from placebo completed the study. We know relatively little about those who dropped out and those who stayed in. The higher dropout rate of vilazodone also signals that tolerability may be an issue with the drug.

This article originally appeared in The Carlat Addiction Treatment Report -- current coverage of topics in addiction medicine.
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PRACTICE IMPLICATIONS: Regardless of whether the current study points to the ineffectiveness of vilazodone or leaves us wondering about the validity of the findings, nothing has changed from a practice standpoint. Psychosocial interventions should continue as first-line treatments.


Combining Alcohol With Caffeinated Energy Drinks Leads to Increased Alcohol Consumption

REVIEW OF: Marczinski C et al. Desire to drink alcohol is enhanced with high caffeine energy drink mixers. Alcoholism: Clinical and Experimental Research, 2016; ahead of publication

STUDY TYPE: Double-blind, placebo-controlled trial

Combining caffeine-based energy drinks and alcohol has become a popular practice among social drinkers over the past decade. Users say that the caffeine enhances their buzz and allows them to drink for longer periods of time. Clinicians and health officials, however, have voiced concerns that such mixed drinks reinforce unsafe alcohol use. Responding to these concerns, in late 2010, the FDA banned pre-mixed alcohol and energy drink cocktails from the market. However, the practice continues in bars, restaurants, and homes.

The FDA’s ban was based mainly on the limited evidence derived from anecdotal and case reports. That’s why researchers from Kentucky conducted a double-blind, placebo-controlled study asking the question, “Do social drinkers consume more alcohol when they drink caffeine and alcohol together, or when they drink alcohol by itself?” To answer this question, 26 social drinkers (>12 ounce beer or 5 ounce glass of wine per month) between the ages of 21 and 30 were recruited to drink 6 different concoctions during 6 separate sessions. This was not a randomized trial: All participants imbibed each of the possible beverages.

Beverages included: a) vodka + decaf soda; b) vodka + Red Bull (1:3 ratio); c) vodka + Red Bull (1:6 ratio); d) decaf soda alone; e) small Red Bull alone; and f) larger Red Bull alone. The vodka drinks contained 1.21 ml/kg of Smirnoff 40% alcohol, which amounts to about two shot glasses for the average 72-kg participant in the study.

Various strategies were used to ensure that participants were blinded to the type of drink they received. For example, in the no-alcohol conditions, a trivial, very thin layer of alcohol was poured on top of the beverage to make it smell like booze. The main outcome measure used was the “Desires-For-Drug” rating scale, which was given to the participants 10 minutes after each drink and repeated about every 20 minutes until 80 minutes had elapsed.

RESULTS: The drinks with alcohol mixed with Red Bull were the clear favorites. When participants drank either of these, they reported higher degrees of liking the drinks, feeling them, and desiring alcohol as compared to any of the other drinks, including vodka plus decaf.

CATR’S TAKE: This small study adds to the existing evidence from other studies showing that people feel more stimulated and more prone to drink more alcohol when they combine caffeine with alcohol vs. drinking alcohol alone. As the authors mention, it’s possible that any stimulant, including nicotine (very frequently consumed with drinks), would have a similar alcohol-enhancing effect.

Research Updates in Addiction: Cannabis and Alcohol

This article originally appeared in:

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This article was published in print September/October 2016 in 4:7.


APA Reference
Moore,, B. (2018). Research Updates in Addiction: Cannabis and Alcohol. Psych Central. Retrieved on October 29, 2020, from


Scientifically Reviewed
Last updated: 30 Mar 2018
Last reviewed: By John M. Grohol, Psy.D. on 30 Mar 2018
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