Kids who smoke cannabis before their 15th birthday, perform much worse in mental tests than those who start at a later age, according to researchers. The study was done in chronic cannabis users and it found that those who started in their early teens struggled with a range of neuropsychological tasks.
But those who started later, didn’t have the same difficulties, says a study published in the British Journal of Psychiatry. Now these findings add to the growing evidence that the drug damages the developing brain, with greater harm caused by early exposure.
In the Uk, marijuana is the most common illicit drug among adolescents, with more than four in ten admitting having taken it. The research was done at the Federal University of Sao Paulo in Brazil looked at the mental functioning of 100 cannabis users after around ten years of consistent use, and almost 50 non-users. And 49 early users whose habit began before the age of 15 were much worse at sustained attention, impulse control and executive functioning.
And in a card sorting test the younger users made many more errors than 55 other test subject, who started using at a later age.
Lead researcher Dr Maria Fontes said: ‘We found that early-onset, but not late-onset, chronic cannabis users had deficits in their cognitive functioning. ‘Adolescence is a period in which the brain appears to be particularly vulnerable to the neurotoxic effects of cannabis. The brain before the age of 15 is still developing and maturing, so exposure to cannabis during this period may be more harmful.’
The earliest age of the users studied was 10.9 years of age, equating to a lifetime consumption of 6,790 joints each.
Janet
/ 01/10/2012and now we have more research findings….
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