Major study reveals drug 'damages children's brains' and half a MILLION adults could avoid mental-health disorder if they had turned down marijuana
Largest study of its kind found that 7% of adult depression could be prevented
Drug has also been linked to suicidal thoughts and attempts
Researchers say tackling the use of millions of under 18s should be a priority
PUBLISHED: 14 February 2019
Smoking cannabis in your teenage years raises the risk of depression and suicide in later life, a landmark new study has found.
Researchers from the US and UK have revealed the drug could impair a child's brain to the extent it triggers mental health disorders later in life.
In the largest research of its kind, experts from Oxford University and McGill University estimated that over half a million adults in the UK and US could be saved from mental health disorders by avoiding the drug as a teenager.
The teams have now warned that cannabis, legal in several US states and used by millions of young people is a significant public health risk with 'devastating consequences'. They have urgently called for officials to make tackling use of the drug a priority.
'It's a big public health and mental health problem, we think,' co-author Professor Andrea Cipriani, from the University of Oxford, said.
'The number of people who are exposed to cannabis, especially in this vulnerable age, is very high and I think this should be a priority for public health and the mental health sector.'
The researchers, at McGill University and the University of Oxford, analysed data from 11 studies involving more than 23,000 individuals.
Date: February 2019 Source: University of Illinois at Chicago
Summary: Lasting changes in the brain caused by drinking that starts in adolescence are the result of epigenetic changes that alter the expression of a protein crucial for the formation and maintenance of neural connections in the amygdala -- the part of the brain involved in emotion, fear and anxiety.
The students who were current vape users were more likely to use other substances or to engage in sexual activity than were nonusers (Table 1). These data corroborate a recent study that showed an association between vaping and risky sexual, substance-use, and violence behaviors.5 These associations are not causal but suggest that certain students are inclined toward a variety of risky behaviors.
The study – completed by researchers at the University of Montreal – followed 3,800 Montreal teens over the course of four years. As part of the study, teen participants were questioned about their marijuana and alcohol use, and took computer-based cognitive tests.
They found that marijuana had more of an effect on the teens’ skills, memory and behavior than alcohol… Even after students reported stopping marijuana, their cognition did not improve.
“Cannabis causes cognitive impairment and delayed cognitive development in adolescents," Patricia Conrad, the lead author and professor of psychiatry at the University of Montreal, told NBC News. “This study focuses on the neuropsychological effects of cannabis. We think it’s important because it is linked to how someone functions in life.”
The findings were published in the American Journal of Psychiatry.