Cannabis is the most widely used illicit substance among adolescents today, with usage typically starting between the ages of 12 and 17. A new study led by Professor Mary Cannon at RCSI University of Medicine and Health Sciences, identifies the key risk and protective factors influencing cannabis use among young people.

Published in the Irish Journal of Psychological Medicine, the paper is based on a secondary analysis of the Planet Youth Survey, which sampled 4,404 adolescents aged 15-16 from both rural and urban areas.

Professor Cannon, alongside co-investigator and PhD scholar Ronan Fleury, and co-author Dr Teresa O’Dowd from the Health Service Executive (HSE) explored a range of factors impacting levels of cannabis usage among this group, including peer behavior, parental attitudes, levels of parental supervision, perception towards cannabis and other drug use.

Key risk factors

The research found that parental attitudes towards cannabis have a strong impact on their child’s likelihood to use cannabis. Adolescents who were under less supervision by their parents and guardians were significantly more likely to use the drug.

Young people whose parents expressed firm opposition towards cannabis were less likely to use the drug. Among non-cannabis users, 95.4% of respondents defined their parents' views on cannabis as being ‘totally against’ compared to 65.6% of the parents of young people who had used cannabis.

“Parental supervision can act as a protective factor," explained Professor Cannon, Professor of Psychiatric Epidemiology and Youth Mental Health at RCSI. “Parents have an important role to play in reducing cannabis use in their adolescent children through their own attitudes and behaviour.”

For the young people themselves, having friends who used cannabis and experiencing peer pressure emerged as significant factors in cannabis use. Young people whose friends used cannabis were 10 times more likely to use cannabis than those whose friends did not. Similarly, participants who felt pressure to use cannabis in order to fit in with their friends and classmates had significantly increased levels of cannabis use compared to those who did not experience peer pressure.

“Our research found that other behaviours typically motivated by peer pressure, such as alcohol consumption, smoking, and the use of e-cigarettes, were also strongly linked to increased cannabis use,” said Ronan Fleury who carried out the research at the RCSI Department of Psychiatry. “The results show that 80.8% of cannabis users also consumed alcohol, 62.3% smoked tobacco, and 71.2% used e-cigarettes and vapes.”

Implications of the study

Concerning trends were also observed in attitudes towards cannabis with 78% of cannabis users perceiving the drug to be non-harmful, while only 16.6% of non-users shared this view. “Educating young people on the risks involved in cannabis use is more vital than ever,” added Professor Mary Cannon. “The push to legalise cannabis in several countries worldwide has influenced public opinion on cannabis and reduced knowledge on the harmful side effects associated with its use.”

While the study identified key risk factors associated with cannabis use it also highlighted potential protective variables, including knowledge of cannabis-related harm, parental supervision, and the perception of guardians being opposed to cannabis use. The findings highlight the need to address both risk and protective factors in public health and education campaigns.

This research was supported by the Health Research Board. This publication has also emanated from research supported in part by grants from the Health Research Board, Research Ireland and by an RCSI summer studentship.