The synergy between loneliness and cannabis use on suicidal thoughts and behaviors among young adults in higher education

BackgroundLoneliness continues to be a public health crisis, and cannabis use has increased among some young adults following its legalization in certain states. Loneliness and cannabis use each contributes to suicide risk, but no studies have explored their potential synergy. This study aimed to explore the interaction between loneliness and cannabis use among students in higher education.MethodsWe analyzed data from the Healthy Minds Study (2020-2021; N = 101,744) and used multivariable logistic regression models to show the synergy between loneliness and cannabis use on suicidal thoughts and behaviors adjusting for sociodemographic variables and mental health. We calculated the interaction contrast ratio to show the synergy of combined exposures.ResultsWhile loneliness and cannabis use both increased odds of suicidal thoughts, those who were lonely and used cannabis had the greatest odds, exceeding the sum of these individual effects. The synergy between loneliness and cannabis use on suicide attempt was not statistically significant at a conventional level.ConclusionSynergy exists between loneliness and cannabis use in relation to suicidal thoughts among young adults in higher education. Future research can explore the utility of screening and addressing loneliness and cannabis in tandem for suicide prevention.