Potheads Lose Brainpower

A study of marijuana’s mounting neuropsychological effects over time tracked a group of 1037 children born in New Zealand for 38 years from the times of their births in 1972 and 1973. Adults who smoked marijuana early and often in life face a higher likelihood of shearing off IQ points and performing more poorly on tests of reasoning, attention and memory than those who smoked pot less often. The collective loss of brainpower among pot smokers held even after the researchers adjusted for differences in the education levels achieved by those who did and those who didn’t smoke pot. “Collectively, these findings are consistent with speculations that cannabis use in adolescence, when the brain is undergoing critical development, may have neurotoxic effects,” the authors concluded. The research is published in the journal Proceedings of the National Academies of Science.