Lonelier Young Adults Used Cannabis More Often and Had Higher Rates of Cannabis Use Disorder

What the researchers found

Using marginal structural modeling to control for multiple confounders, loneliness at ages 21 and 23 predicted greater cannabis use frequency at subsequent waves (OR 1.13 per SD increase, 95% CI 1.06-1.20). Loneliness also predicted higher cannabis use disorder risk (prevalence ratio 1.20, 95% CI 1.12-1.29) and hazardous alcohol use (PR 1.10, 95% CI 1.03-1.17). The cannabis associations held after accounting for depression, prior substance use, and other psychosocial factors.

Why it matters

In an era of rising loneliness and social isolation, this study establishes that loneliness independently predicts problematic cannabis use, separate from depression. This suggests that addressing loneliness and social connection could be a novel approach to preventing cannabis use disorders in young adults.

The numbers in context

4,407 participants. Loneliness and cannabis frequency: OR 1.13 (95% CI 1.06-1.20). Cannabis use disorder: PR 1.20 (95% CI 1.12-1.29). Hazardous alcohol use: PR 1.10 (95% CI 1.03-1.17). Measured ages 21-26.

How the study worked

Data from 4,407 young adults in the Community Youth Development Study. Loneliness measured at ages 21 and 23; substance outcomes at ages 23 and 26. Marginal structural modeling accounted for time-fixed and time-varying confounders including depressive symptoms, prior substance use, and psychosocial factors. Cannabis use disorder diagnosed using validated criteria.

What this study cannot tell us

Two-year lag between loneliness and outcome assessments may miss shorter-term dynamics. Self-reported loneliness measure (4 items). Marginal structural models address but cannot eliminate all confounding. Sample from community study may not represent all young adults.

How to read the evidence

Strong: large longitudinal sample (N=4,407) with sophisticated causal modeling controlling for extensive confounders.

When this study was published

2025 study

The bigger picture

Loneliness is increasingly recognized as a public health crisis. This study adds substance use to the growing list of loneliness-related health consequences. The finding that loneliness predicts cannabis problems independently of depression suggests loneliness may operate through distinct pathways, potentially social reinforcement or emotion regulation.

Questions still open

• Would interventions targeting loneliness reduce cannabis use disorders? Does cannabis use itself worsen loneliness, creating a feedback loop? Are different types of loneliness (social vs emotional) differentially related to cannabis use?

Common questions

Read the original research

The Longitudinal Relationship of Loneliness With Frequency and Problematic Use of Alcohol and Cannabis Among Young Adults.

The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 77(5), 917-923

Citation

Rhew, Isaac C; Cadigan, Jennifer M; Guttmannova, Katarina; Caouette, Justin D; Kuklinski, Margaret R; Oesterle, Sabrina. (2025). The Longitudinal Relationship of Loneliness With Frequency and Problematic Use of Alcohol and Cannabis Among Young Adults.. The Journal of adolescent health : official publication of the Society for Adolescent Medicine, 77(5), 917-923. https://doi.org/10.1016/j.jadohealth.2025.06.037

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