Loading...
A recent meta-analysis of studies (NEJM JW Psychiatry Jun 2018 and JAMA Psychiatry 2018; 75:585) found small-sized adverse cognitive effects with cannabis use but only in studies requiring fewer than 3 days of abstinence. This finding has led some clinicians to assume that use several times a week is cognitively and clinically harmless. In the current study, researchers assessed cognition weekly, including memory and attention, after randomizing teen and young adult cannabis users (age range, 16–25; mean use, 55 of the last 90 days) to 4 weeks of abstinence (n=62) or continued use (n=26).
The rates of comorbid psychiatric diagnoses or cannabis dependence symptoms were very low. In almost 90%, abstinence was validated by urinary concentration…