Can smoking marijuana make you dumber? Maybe so.
Last month BBC News reported on a new international study that looked at how smoking pot affects intelligence.
The researchers found that young people who smoke marijuana long-term may run the risk of a “significant and irreversible reduction in their IQ.”
The findings come from a study of around 1,000 people in New Zealand. All of them had started using marijuana in their teens, and they were carefully followed over a 20 year period.
Those who persistently used pot--smoking it at least four times a week through their teens and 20s, suffered a decline in their IQ.
The more that people smoked, the greater the loss in IQ.
The effect was most significant in those who started smoking marijuana as teenagers.
Stopping or reducing marijuana use failed to fully restore their lost IQ.
Robin Murray, a professor of psychiatric research at the King's College London Institute of Psychiatry, says the research might explain why people who use the drug often seem to under-achieve.
Dr. Murray points out that for years it’s been commonly believed that heavy pot smokers “seem to gradually lose their abilities and end up achieving much less than one would have anticipated.” He says “This study provides one explanation as to why this might be the case.”
I’m Bill Maier for WBCL.