Young teenagers who try marijuana dramatically lower their IQ and raise their risk of developing brain dysfunction, depression, and bipolar disorder, a new study claims.
The younger the brain, the weaker it is as it grows and strengthens, scientists at Canada’s Western University warn.
And their research shows marijuana can have a devastating affect on that development process.
The younger the brain, the weaker it is as it grows and strengthens, scientists at Canada’s Western University warn – leaving teenagers open to severe brain impairment smoking weed
According to the study, published today, cannabis severely impaired teens’ visuo-spatial processing, memory, self-referential activity and reward processing.
The study found that early marijuana use was also associated with lower IQ scores.
And the younger they started using the drug, the worse their impairment was.
Marijuana also did nothing to alleviate symptoms of depression in teens – despite claims by pro-legalization groups that this is a key benefit.
In fact, in some regions of the brain, depressive symptoms worsened.
‘These findings suggest that using marijuana does not correct the brain abnormalities or symptoms of depression and using it from an early age may have an abnormal effect not only on brain function, but also on IQ,’ said lead author Dr Elizabeth Osuch, one of Canada’s leading figures in exploring marijuana’s link to psychiatric disorders.
Dr Osuch’s team recruited young people in four groups.
First was those with depression who were not marijuana users.
Second, those with depression who were frequent marijuana users.
Third, frequent marijuana users without depression.
Fourth, healthy individuals who were not marijuana users.
They later divided the participants into subgroups: those who started using marijuana before the age of 17, and those who began using it later or not at all.
Each teen was given psychiatric, cognitive and IQ tests as well as a brain scan.
They also performed genetic tests on each participants, since studies have shown people who get depressed smoking marijuana may have inherited it.
Dr Osuch warned the study was small, and more research is required.
Their next step is to explore their finding that young weed smokers could be genetically predisposed to trying marijuana early.
They discovered that young people who used marijuana from an early age had a higher proportion of a certain genetic variation of a brain development gene.
‘This is a novel finding that suggests this genetic variation may predispose youth to early marijuana use,’ said Dr. Osuch.
The study is published in the journal Acta Psychiatrica Scandinavica.