Smoking marijuana as a teenager lowers IQ for life, scientists warn.



  • The damaging effects remain even if the person stops smoking the drug
  • Teenagers are at particular risk because their brains are still developing
  • Smoking cannabis affects critical thinking and memory
  • Researchers warn that stronger varieties today are causing more damage 


Smoking cannabis as a teenager lowers IQ into adulthood and could have a lifelong impact, researchers have warned.   U.S. researchers found the damaging effects of the drug remained even if users stopped smoking marijuana as adults.  They said teenagers face increased risks from smoking cannabis, because the brain is rapidly developing at this time.


Smoking cannabis as a teenager lowers IQ in adulthood and could have a lifelong impact, research suggests  The scientists, from the National Institute of Drug Abuse (NIDA) in the U.S., added that smoking cannabis affects critical thinking and memory during use, with the effects persisting for days.


Reviewing a range of studies on marijuana smoking, they reiterated that cannabis impairs driving and increases the risk of being involved in a car accident.  The risks are further enhanced when combining marijuana with alcohol, they reported in the New England Journal of Medicine.  The panel looked into areas where little research had been previously conducted.


Those areas included the consequences of second-hand marijuana smoke, the long-term impact of prenatal marijuana exposure, the therapeutic potential of the individual chemicals found in the marijuana plant, and the effects of marijuana legalisation policies on public health in the U.S.


Stronger health effects may occur with today’s more potent marijuana, they warned, as older studies are based on the effects of lower-potency marijuana. ‘It is important to alert the public that using marijuana in the teen years brings health, social, and academic risk,’ said lead author and NIDA director Dr Nora D. Volkow.


The damaging effects of the drug persist even if a person stops smoking it in adulthood.


‘Physicians in particular can play a role in conveying to families that early marijuana use can interfere with crucial social and developmental milestones and can impair cognitive development.’


Recently, researchers at the University of Pennsylvania, in Philadelphia, found smoking cannabis before the age of 15 could lead to insomnia later in life.  Any history of using the drug was associated with an increased risk of reporting difficulty getting enough sleep.


Participants in the study reported struggling to fall asleep, difficulty maintaining sleep, experiencing non-restorative sleep and feeling sleepy during the day.  The strongest link between lack of sleep and cannabis use was in those who first used the drug under the age of 15.


Source:  http://www.dailymail.co.uk/health/article-2650631/Smoking-marijuana-teenager-lowers-IQ-LIFE-scientists-warn.html