The interplay between cannabis use and suicidal behaviours: epidemiological overview, psychopathological and clinical models

Objectives The clinical and psychopathological relationships between substance use and suicidal behaviours are deserving growing attention. Understanding and identifying factors that may be associated with suicidal behaviours can help clinicians to early detect high-risk individuals. Methods We conducted a narrative review, summarising main epidemiological data from longitudinal studies, on the potential association between cannabis use and suicidal behaviours. In addition, we discuss possible psychopathological models that may explain and disentangle this clinical relationship. Results Individuals who use cannabis, the most common psychoactive drug apart from alcohol and nicotine, may have higher risk of suicidal behaviours. Despite the mixed findings, evidence seems to suggest that an early and heavy cannabis use may be associated with suicidal ideation, attempt, and completion. Conclusions Findings from our review show that it is likely that cannabis is associated with increased rates of suicidal behaviours. This relationship could be explained by the reciprocal influence of cannabis on severity of depression, psychotic features, and impulsivity. Cannabis may play a key role in the complex clinical pathways that link mental disorders and suicide-related behaviours. Nevertheless, various potential mechanisms and contributing factors to this association remain to be investigated.