Clinical Takeaway
Cannabis can increase or decrease the urge to drink alcohol depending on a person’s working memory capacity, meaning the mental ability to hold and manage information. People with lower working memory capacity may be more vulnerable to cannabis increasing their alcohol cravings, while those with higher capacity may respond differently. This suggests that cognitive factors play a measurable role in how cannabis and alcohol interact in real users.
#15 Working memory capacity predicts cannabis-induced effects on alcohol urge.
Citation: Gunn Rachel L et al.. Working memory capacity predicts cannabis-induced effects on alcohol urge.. Addictive behaviors. 2026. PMID: 41275744.
Design: 5 Journal: 0 N: 2 Recency: 3 Pop: 2 Human: 1 Risk: -2
Working memory capacity may identify which patients are likely to benefit from cannabis as a potential therapeutic tool for reducing alcohol craving, addressing the clinical heterogeneity that has limited its use in addiction treatment. This finding suggests that personalized pharmacological approaches based on cognitive phenotyping could improve outcomes in dual alcohol-cannabis use disorder management. Understanding individual neurobiological predictors of cannabis efficacy on alcohol urge is essential for developing targeted interventions and reducing the risk of unintended consequences in vulnerable subpopulations.
Quality Gate Alerts:
- Preclinical only
Abstract: BACKGROUND: Cannabis has shown mixed results in its association with alcohol urge, which may be explained by individual differences. One such factor, working memory capacity (WMC) is associated with drug-related cue reactivity and implicated in alcohol use and problems. In the current study, we examined whether WMC moderates the acute effect of cannabis on alcohol urge in a randomized placebo-controlled crossover trial. METHODS: Participants aged 21 to 44 (N = 125, 32 % female) reporting heavy alcohol use and cannabis use ≥ twice weekly completed a laboratory protocol across three days where they smoked a placebo, 3.1 % delta-9 tetrahydrocannabinol (THC), and 7.2 % THC cannabis cigarette. Participants were asked to rate their alcohol urge pre and post smoking. Prior to the experimental sessions, participants completed WMC measures including the n-back and the complex span tasks, operation span (OS) and symmetry span (SS). RESULTS: Those with higher WMC, as assessed via the SS task, reported significantly lower alcohol urge after smoking the 7.2 %, but not the 3.1 %, THC dose, relative to placebo. Performance on the OS task was not associated with alcohol urge. Lower WMC as determined via n-back scores was associated with higher alcohol urge overall, but n-back scores did not moderate the impact of cannabis on alcohol urge. CONCLUSION: Findings suggest individuals with higher but not lower working memory experience lower alcohol urge under acute effects of cannabis. Although cannabis is increasingly perceived as a substitute for alcohol, individuals with lower working memory may be less likely to experience such benefits when attempting to reduce their drinking.
🧠 This crossover trial suggests that working memory capacity may explain individual variability in how cannabis affects alcohol cravings, which is a clinically relevant finding given the common comorbidity of cannabis and alcohol use. However, the study’s reliance on acute laboratory administration rather than real-world use patterns, the relatively young and selected sample, and the lack of data on how this effect translates across different cannabis formulations, doses, and consumption methods all limit generalizability to typical patients. The mechanistic link between working memory function and cannabis-alcohol interactions remains largely unexplored, leaving open questions about whether this represents a true biological moderation or a proxy for other unmeasured cognitive or psychiatric factors. Despite these limitations, the work highlights an important principle: cannabis does not affect all patients uniformly, and baseline cognitive function may be one variable worth considering when counseling patients about potential interactions with alcohol. Clinically, this suggests we should screen for cognitive vulnerabilities and discuss individualized responses rather than assuming universal effects when cannabis and alcohol use coincide.