Cannabis use by teenagers may not be responsible for poor school results, according to a major study.
Only heavy cannabis use is linked to poor exam results, according to the study of more than 2,000 children from Bristol, UK.
The findings were reported to the conference of the European College of Neuropsychopharmacology in Berlin, Germany.
According to the researchers, cannabis use in teenagers is closely linked to other unhealthy behaviour, such as using alcohol and cigarettes.
According to their analysis, these are more likely to explain declining academic performance than cannabis itself.
Researcher Claire Mokrysz, of University College, London, UK, said: "People often believe that using cannabis can be very damaging to intellectual ability in the long-term, but it is extremely difficult to separate the direct effects of cannabis from other potential explanations.
"It’s hard to know what causes what- do kids do badly at school because they are smoking weed, or do they smoke weed because they’re doing badly? This study suggests it is not as simple as saying cannabis is the problem."
She added: "This is a potentially important public health message – the belief that cannabis is particularly harmful may detract focus from and awareness of other potentially harmful behaviours. However the finding that heavier cannabis use is linked to marginally worse educational performance is important to note, warranting further investigation."
College chair Professor Guy Goodwin said: "This is a potentially important study because it suggests that the current focus on the alleged harms of cannabis may be obscuring the fact that its use is often correlated with that of other even more freely available drugs and possibly lifestyle factors.
"These may be as or more important than cannabis itself."
Leave a Reply