THC, but not CBD, tied to distressing psychological episodes

Just one dose of THC, or about the same as smoking one joint, can induce a serious psychological state, a new review of 15 previous studies reports. Combing through data from 331 people without a history of psychiatric disorders, the reviewers found that study participants who took the psychoactive ingredient in cannabis were more likely to experience temporary symptoms of psychosis, depression, and anxiety than people who took a placebo. Four of the studies looked at whether cannabidiol (CBD) made a difference and found that it didn’t duplicate or moderate the effects they saw with THC. “This potential risk should be considered in discussions between patients and medical practitioners thinking about using cannabis products with THC,” a review co-author wrote.

Correction: An item in yesterday's newsletter gave an incorrect number of alcohol-involved crashes from 2000 through 2015. That figure is 223,471.