MONTREAL, October 4,, 2021 – The idea that alcohol, cannabis, and other drug abuse and dependence disorders lead to suicidal tendencies in adolescents and young adults is being challenged by the results of a new study conducted at CHU Sainte-Justine and the Université de Montréal (UdeM) and published in PLOS ONE.

"For the first time ever, our meta-analysis reveals that the likelihood of suicidal tendencies preceding substance use disorders is equally high," says Charlie Rioux, a graduate of the doctoral program in the Department of Psychology at UdeM and the CHU Sainte-Justine Research Centre, and first author of the study.

Adolescence: a difficult period

Adolescence is often a time of great vulnerability, discovery and search for autonomy. Some young people, for various reasons, will turn to substance use, but will also find themselves struggling with suicidal thoughts and behaviours.

Problematic substance use and concomitant disorders among youth have multiple negative physical and psychological consequences. At the same time, suicidal tendencies, which typically emerge and peak during adolescence, often reflect other mental health problems.

Several studies have shown that the link between substance use and susceptibility to suicidal ideation in adolescent and adult populations could be explained developmentally by four hypotheses.

The research team focused on 1) the hypothesis that substance use disorders lead to suicidal tendencies through increased psychological distress and impulsivity, or substance-induced depression; and 2) the hypothesis of self-medication or use of substances to gain peer acceptance so as to cope with suicidal ideation.

“Although a number of meta-analyses on the association between substance use and suicidal tendencies have been conducted recently, none examined how both influence each other", says Natalie Castellanos-Ryan, researcher at CHU Sainte-Justine and associate professor at UdeM's School of Psychoeducation.

25 studies under review

The meta-analysis examined 25 published studies of these associations.

The analysis highlights a bias in the research that ignores the fact that young people may use substances as a response to suicidal thoughts. The study also highlights the fact that the research models in the vast majority of current studies fail to specify how substance use disorders and suicidal tendencies can develop together.

According to Jean Séguin, researcher at CHU Sainte-Justine and professor in the Department of Psychiatry and Addiction at UdeM, "if the young person in distress is to be diagnosed and treated appropriately and effectively, it is essential to clarify these issues. Clinically, providers tend to focus on one problem or another because mental health and addiction services are often not well integrated into emergency or primary care."

Vigilance is needed

The study suggests that associated disorders should be assessed and treated concomitantly and that clinicians should be vigilant about substance use initiation in young patients with suicidal thoughts or attempts.

"A better understanding of the developmental and two-way association between substance use and suicidal tendencies and how these may change over developmental periods will allow for improved prevention and intervention programs by age group," concludes Charlie Rioux.

About the study

The article titled "Substance use disorders and suicidality in youth: A systematic review and meta-analysis with a focus on the direction of the association", written by Charlie Rioux, appeared in the journal PLOS ONE in August 2021. The study was supported by the Monique Gaumond Fund for Research in Affective Diseases, the Canadian Institutes of Health Research, the Fonds de recherche du Québec – Santé, the American Foundation for Suicide Prevention, and the Réseau québécois sur le suicide, les troubles de l'humeur et les troubles associés.

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