Cannabis use can lead to suicidal thoughts

[OZ Stoners]

A major 30-year longitudinal study has found that regular cannabis use is a risk factor for the onset of suicidal ideation for males, delegates will be told today at a national conference.

Previous studies have found that suicidal ideation is often more prevalent among regular cannabis users than it is among those who have never used the drug regularly. This study aimed to determine the extent to which this correlation represents a causal relationship. The researchers were able to identify that regular cannabis use is indeed a risk factor for suicidal ideation and that it is not suicidal ideation that causes cannabis use.

The study was part of the Christchurch Health and Development Study, which followed a cohort of children born in Christchurch, New Zealand over 30 years.

Professor Jenny Williams, from the University of Melbourne, will be presenting the study’s findings at the 2nd National Cannabis Conference, held in Brisbane from 19-21 September 2012. The conference is run by the National Cannabis Prevention and Information Centre (NCPIC), which is based at the University of New South Wales.

“The good news is that we find no evidence that suicidal thoughts cause young people to turn to cannabis,” said Professor Williams. “However, our results also indicate that the earlier that intense use (at least several times per week) first occurs, the faster susceptible individuals start having suicidal thoughts.”

The study also found that the higher the frequency of cannabis use, the faster susceptible individuals start having suicidal thoughts.
“For example, our modelling suggests that if all males used cannabis at an intensity of less than several times a week, the population prevalence of suicidal ideation for males would grow from 15% for 18 year olds, to 24% for 21 year olds and 30% for 30 year olds in the cohort studied,” said Professor Williams.
“By contrast, if they all started using cannabis several times a week from the age of 17, then the population prevalence of suicidal ideation for males would increase to 24% for 18 year olds and 31% for 21 year olds. If instead, the cohort of males all started using cannabis daily at the age of 17, the entire population of susceptible males, around 31%, will have had suicidal thoughts by the age of 18.”
Globally, suicide has emerged as the second leading cause of death among youth aged 10-24 years old. There continues to be much debate as to the role cannabis use may play in the rise of youth suicide. Although use has declined in recent years, cannabis continues to be the most popular illicit drug amongst young people and stronger evidence is emerging regarding the potential negative mental health effects associated with its use.

“This study’s findings are important for the development of appropriate public health messages around suicide prevention and cannabis use,” said Professor Jan Copeland, Director of NCPIC.

“The loss of a young person to suicide is a personal, family and community tragedy and any risk that can be modified, such as early and frequent cannabis (and alcohol) use is an important message for young people and their families to take on board.”

NCPIC is an Australian Government initiative supported by the Department of Health and Ageing.

Cannabis Information and Helpline – 1800 30 40 50
NCPIC website – www.ncpic.org.au
ends

Contact Details:
Morag Millington, tel. 0431 981 046, (02) 9385 0213, email: m.millington@unsw.edu.au
Paul Dillon, tel. (02) 9385 0226, 0419 402 099 email p.dillon@unsw.edu.au
Date Issued: 19 September 2012

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