Marijuana is the world’s most widely used illicit drug. But smoke too many joints too soon, and you might lose IQ points: A new study suggests extensive marijuana use starting as a teenager could lead to cognitive decline.
In a study of 1,037 New Zealanders followed from birth to age 38, people who began using marijuana as adolescents and used it extensively for years saw their IQs drop by about eight points. What’s more, among adolescent-onset users, quitting the drug did not reverse the mental deficits.
“Marijuana is not…” click to read the full article