Near-daily cannabis users show normal neural value encoding for cannabis but disrupted encoding for non-drug rewards like snacks, even when their actual choices are equivalent. The study used a neuroeconomic framework to measure brain activity while participants chose between varying amounts of cannabis or snacks and money. Value signals for cannabis appeared in brain regions typically involved in reward processing (ventromedial prefrontal cortex, ventral striatum, dorsal posterior cingulate cortex), but these signals were weaker or absent for snacks. The findings support the idea that problematic substance use involves dysregulated neural valuation of non-drug rewards.
In adults with obsessive-compulsive disorder (OCD), smoked cannabis containing primarily THC or CBD had little acute effect on OCD symptoms and produced smaller reductions in anxiety than placebo. In a randomized, placebo-controlled, within-subjects laboratory study, 12 participants completed three sessions smoking placebo (0% THC/0% CBD), THC (7.0% THC/0.18% CBD), or CBD (0.4% THC/10.4% CBD). Self-reported OCD symptoms and anxiety decreased over time in all conditions, but OCD symptoms did not differ by cannabis varietal. State anxiety was significantly lower immediately after placebo than after either active cannabis. THC increased heart rate, blood pressure, and intoxication relative to placebo and CBD.