Large longitudinal study finds cannabis use predicts increasing anxiety, but anxious people actually reduce their cannabis use | Research

The takeaway

In nearly 3,000 young adults followed from ages 17-24, greater cannabis use predicted subsequent increases in anxiety, but higher anxiety was associated with decreasing cannabis use, with important sex differences in these patterns.

Mental health clinicians, cannabis users with anxiety, and researchers studying substance-mental health relationships.

Cannabis increased anxiety; anxiety decreased cannabis use (not self-medication)

What the researchers found

For the overall sample and men, greater cannabis use predicted greater subsequent increases in anxiety (substance-induced pathway). However, greater anxiety was associated with decreasing, not increasing, cannabis use (contradicting the self-medication hypothesis). For women, the patterns were more complex, with trait-like anxiety predicting increasing anxiety but recent anxiety increases associated with reduced cannabis use.

Why it matters

This study challenges the popular self-medication hypothesis by showing anxious people actually tend to reduce cannabis use, while supporting the idea that cannabis use can increase anxiety over time.

The numbers in context

N=2,995; ages 17-24; 6 measurement waves. Cannabis use predicted increasing anxiety. Anxiety predicted decreasing cannabis use. Sex-specific models revealed different patterns for men and women.

How the study worked

Data from a longitudinal cohort study (N=2,995) using an accelerated longitudinal design from ages 17-24. Latent difference score models estimated bidirectional relationships between anxiety and cannabis use across 6 waves, separately for men and women.

What this study cannot tell us

Self-reported measures. Cannot account for all confounders. Southern California sample. Cannabis use measured by frequency, not dose or potency. Accelerated longitudinal design assumes cohort equivalence.

How to read the evidence

Large longitudinal cohort with sophisticated bidirectional modeling, strengthened by sex-stratified analyses.

When this study was published

Published in 2022.

The bigger picture

The finding that the self-medication pathway (anxiety driving cannabis use) is not supported, while the substance-induced pathway (cannabis driving anxiety) is, has implications for how we understand and treat co-occurring anxiety and cannabis use.

Questions still open

Why does the self-medication hypothesis fail here? Do anxious people recognize cannabis worsens their anxiety? Would different cannabis products (high-CBD) produce different anxiety trajectories?

Common questions

Do anxious people use more cannabis to cope?

Contrary to the self-medication hypothesis, this study found that increasing anxiety was actually associated with decreasing cannabis use, suggesting anxious people tend to cut back rather than self-medicate with cannabis.

Does cannabis cause anxiety?

This study supports the substance-induced pathway: greater cannabis use predicted subsequent increases in anxiety symptoms over time, particularly in men and the overall sample from ages 17-24.

Read the original research

Directional associations between cannabis use and anxiety symptoms from late adolescence through young adulthood.

Drug and alcohol dependence, 241, 109704

View on PubMed ↗Publisher’s paper ↗

Citation

Davis, Jordan P; Pedersen, Eric R; Tucker, Joan S; Prindle, John; Dunbar, Michael S; Rodriguez, Anthony; Seelam, Rachana; D'Amico, Elizabeth J. (2022). Directional associations between cannabis use and anxiety symptoms from late adolescence through young adulthood.. Drug and alcohol dependence, 241, 109704. https://doi.org/10.1016/j.drugalcdep.2022.109704