How cannabis reshapes the brain's reward decision-making

This study examined how people with and without a history of cannabis use make decisions about cannabis-related choices, using advanced behavioral analysis techniques. Sixty participants—half with cannabis use experience and half without—completed a decision-making task where they rated and chose between cannabis-related and unrelated images. The research used a drift-diffusion model to analyze both their choices and response times, revealing how their brains process and value cannabis compared to other rewards.

The key finding reveals fundamental differences in how value gets processed: people with a history of cannabis use showed significantly higher evidence accumulation rates specifically for cannabis-related decisions, meaning their brains gathered information faster when cannabis options were on the table. Interestingly, the control group (without cannabis history) actually valued non-cannabis alternatives MORE than cannabis itself. This pattern directly supports behavioral economic theories suggesting that cannabis dependence involves distorted valuation processes—essentially, cannabis becomes disproportionately valuable in the decision-making process for regular users.

The results provide neurobehavioral evidence for why cannabis can be difficult to resist for some people: their decision-making systems are fundamentally oriented toward cannabis as a higher-value reward. However, the study also found that response thresholds and decision-making speed for non-cannabis choices remained similar between groups, suggesting the brain changes are specific to cannabis valuation rather than affecting general decision-making capacity. This distinction could inform more targeted intervention strategies for cannabis use concerns.