The commenters are not happy about this.
Bad news, everyone: smoking too much pot as a teen could permanently lower your IQ
One of the most thorough studies of its kind has concluded that smoking too much reefer as a teenager is linked to significant cognitive decline. More frightening still: the effects could be permanent. Here's everything you need to know about the study's findings.
Here's the gist: The study followed 1,037 New Zealanders from birth through age 38, monitoring their IQs and marijuana usage throughout. IQ tests were administered first at age 13 (before the test subjects had started smoking pot), and again at 38, "after a a pattern of persistent cannabis use had developed."
The findings reveal that test subjects who smoked heavily throughout adolescence suffered an average drop of eight points in their IQ scores. According to Madeline H. Meier, first author of the study, this impairment was most prevalent among adolescent-onset cannabis users:
Adolescent onset users, who diagnosed with cannabis dependence before age 18, tended to become more persistent users, but... after equating adolescent- and adult-onset cannabis users on total number of cannabis-dependence diagnoses, adolescent-onset users showed greater IQ decline than adult-onset cannabis users. In fact, adult-onset cannabis users did not appear to experience IQ decline as a function of persistent cannabis use.