Regular Cannabis Use Linked to Declining IQ

A review of long-term data concerning over 6,000 individuals revealed that frequent cannabis use from adolescence onward is associated with a drop in IQ of approximately two points by around age 40. Senior author Dr. Mary Cannon adds, “Previous research tells us that young people who use cannabis frequently have worse outcomes in life than their peers and are at increased risk for serious mental illnesses like schizophrenia. Loss of IQ points early in life could have significant effects on performance in school and college and later employment prospects.” Psychological Medicine, January 2021