Working memory capacity predicts cannabis-induced effects on alcohol urge.
Rachel L Gunn, Lindy K Howe, Holly K Boyle, Jane Metrik
Addictive behaviors March 1, 2026 DOI: 10.1016/j.addbeh.2025.108565 (opens in new tab) via PubMed
Summary
AI-generated from the abstractIn a randomized placebo-controlled crossover trial, 125 adults who drank heavily and used cannabis at least twice weekly smoked placebo, 3.1% THC, or 7.2% THC cannabis cigarettes. Participants with higher working memory capacity, measured by a symmetry span task, reported significantly lower alcohol urge after smoking the higher THC dose compared to placebo. Lower working memory, measured by an n-back task, was linked to higher alcohol urge overall but did not alter cannabis's effect on urge. The authors suggest that individuals with lower working memory may be less likely to experience reduced alcohol craving from cannabis.
Study at a glance
| Characteristics | Randomized placebo-controlled crossover trial Peer reviewed |
|---|---|
| Sample size | 125 |
| Population | Adults aged 21 to 44 reporting heavy alcohol use and cannabis use at least twice weekly |
| Dose | 3.1% delta-9 tetrahydrocannabinol, 7.2% delta-9 tetrahydrocannabinol |
| Topics | Cannabis |
| Keywords | Alcohol craving Delta-9 tetrahydrocannabinol Working memory |
| Key finding | Individuals with higher working memory capacity, as assessed by the symmetry span task, reported significantly lower alcohol urge after smoking 7.2% THC cannabis relative to placebo, while those with lower working memory did not show this effect. |
Abstract
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. 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). 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. 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.