Irish Times Opinion Piece: Cannabis use significantly increases mental health risks

In an article for the Irish Times, Consultant Psychiatrist Professor Mary Cannon discusses the recent rise in cannabis use among young people, and the detrimental effect it can have on their mental health and development.

You can read the full Irish Times article, published on 16/09/19, here.

Accounting for the rise in so-called “recreational” use in teens, Prof Cannon posited that:

‘Until relatively recently, cannabis use among Irish adolescents was in decline. In 2003, 17 per cent of 16-year-olds said they had used the drug in the past month; that number dropped to 7 per cent in 2011. The reverse began soon after. While there’s no single reason for this, one possible explanation is that the percentage of teenagers who view cannabis as “low risk” increased from 10 per cent in 2011 to almost 20 per cent in 2015.’

While numerous scientific studies have shown the effects cannabis can have on the adolescent brain, Prof Cannon highlighted that the public still seem to be largely in the dark over the potential for serious and long-term damage to the health of users stating:

‘There is strong evidence that cannabis use increases the risk of depression and anxiety in young people. The risk of youth suicide increases three-fold. There are a large number of studies now showing that cannabis use causes psychosis. The risk of developing a psychotic illness such as schizophrenia is particularly high in people who start using high potency cannabis during adolescence; it is estimated that 50 per cent of all new cases of first-episode psychosis in Amsterdam are due to cannabis.’

Commenting on legalisation advocates who have touted the end of black market sales, the “war on drugs” and moderation, Prof Cannon points out that the reality of legalisation is much more grim:

‘In Canada and the US states where cannabis is legal for recreational use, the black market still thrives. In Colorado, the first US state to legalise for recreational use, cannabis-related presentations to emergency departments have trebled, and the percentage of drivers involved in fatal car crashes who tested positive for cannabis has doubled.

Children are increasingly being seen in emergency departments with accidental overdoses of “edible” cannabis products such as gummy bears and chocolate. There are also emerging reports of deaths in young people from vaping THC products. Colorado now has more “pot shops” than McDonalds outlets.’

The College of Psychiatrists of Ireland is currently forming a committee on cannabis associated harms to mental health and the wider implications of such harm.