Young adult cannabis users who reported medical use were less likely to use other illicit drugs | Research

The takeaway

Among 301 young adult cannabis users in Los Angeles tracked over four waves, self-reported medical cannabis use was associated with lower illicit drug use, while use of concentrates and edibles was associated with higher overall drug use trajectories.

Substance use researchers, cannabis policy makers, and clinicians working with young adult cannabis users.

Medical cannabis use linked to lower illicit drug use trajectories

What the researchers found

Self-reported medical cannabis use was negatively associated with membership in high illicit drug use trajectories. However, use of concentrates and edibles was associated with high drug use trajectories for both illicit drugs and prescription misuse.

Why it matters

The study suggests that self-reported medical cannabis use may indicate a different relationship with substances than recreational use, while certain cannabis product types may signal broader patterns of drug use.

The numbers in context

301 completers out of 366 enrolled. Two-trajectory solutions (high/low) for both illicit drug use and prescription misuse. Medical cannabis patient status, edibles use, and cannabis days all decreased by wave 4.

How the study worked

Longitudinal study surveying 210 medical cannabis patients and 156 non-patient users in Los Angeles annually over four waves (2014-2018). Developmental trajectory modeling identified high/low groups for illicit drug use and prescription drug misuse.

What this study cannot tell us

Self-reported data may undercount actual drug use. The sample was limited to Los Angeles and may not generalize. The association between product type and drug trajectories does not establish causation.

How to read the evidence

Moderate: longitudinal design with four waves of data, though limited by self-report and single city.

When this study was published

Published in 2020 in Drug and Alcohol Review.

The bigger picture

The declining trends in medical cannabis patient enrollment and cannabis days by wave 4 may reflect California's changing cannabis landscape as recreational legalization approached, suggesting that policy context shapes use patterns.

Questions still open

Does medical cannabis use actually reduce illicit drug use, or do lower-risk users simply prefer the medical framework? How has full recreational legalization in California changed these patterns?

Common questions

Does medical cannabis reduce other drug use?

The study found an association between self-reported medical use and lower illicit drug use trajectories, but it cannot prove that medical cannabis caused the lower use. People who prefer medical frameworks may simply be lower-risk users.

Why were concentrates and edibles linked to higher drug use?

The researchers suggest that people who seek out higher-potency or alternative cannabis products may also be more willing to try other substances. This is a correlation, not evidence that these products cause other drug use.

Read the original research

Developmental trajectories of illicit drug use, prescription drug misuse and cannabis practices among young adult cannabis users in Los Angeles.

Drug and alcohol review, 39(6), 743-752

View on PubMed ↗Publisher’s paper ↗

Citation

Fedorova, Ekaterina V; Schrager, Sheree M; Robinson, Lucy F; Roth, Alexis M; Wong, Carolyn F; Iverson, Ellen; Lankenau, Stephen E. (2020). Developmental trajectories of illicit drug use, prescription drug misuse and cannabis practices among young adult cannabis users in Los Angeles.. Drug and alcohol review, 39(6), 743-752. https://doi.org/10.1111/dar.13078