Regular cannabis users who start using the drug before 15-years of age perform worse on brain tests than those who start using it later.
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No difference was noted in the IQ levels between the three groups. It was found that the early-onset group performed significantly worse than the late-onset group and the control group on tasks which tested their sustained attention, impulse control and executive functioning.
Adolescence is a period during which the brain appears to be particularly vulnerable to the neurotoxic effects of cannabis. Brain imaging studies have shown that the brain is still maturing and developing before 15-years of age and exposure to cannabis during this period may be more harmful and lead to lower mental flexibility.
This research has been published in the June issue of the British Journal of Psychiatry.
Source-Medindia