Cannabis Damages Developing Brain

Cannabis Damages Development

Children who smoke cannabis before their 15th birthday perform worse in mental tests than those who start at a later age.

A study of chronic cannabis users published in The British Journal of Psychiatry (2011) found that users who started in their early teens struggled with a range of neuropsychological tasks.

These findings add to growing evidence that cannabis damages the developing brain, with greater harm caused by early exposure. Cannabis has previously been linked to mental illness in the adolescent.

Cannabis Linked to Psychosis

Loss of attention and control

Research carried out 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, as well as almost 50 non-users.

The researchers found that the 49 users whose habit began before the age of 15 were much worse at sustained attention, impulse control and executive functioning. In a card-sorting test they made many more errors than 55 youngsters who got the habit later and 44 people who had never taken the drug.

Lead researcher Dr Maria Fontes believes that the results are evidence that adolescence is a period in which the brain appears to be particularly vulnerable to the neurotoxic effects of cannabis as the brain before the age of 15 is still developing and maturing.