Recreational Cannabis Laws Are Associated With People Sleeping About 5 Minutes Less | Research

The takeaway

Analysis of 175,493 Americans found recreational cannabis legalization was associated with falling asleep 7 minutes later and sleeping about 5 minutes less per night, concentrated in males over 25.

Sleep researchers, public health policymakers evaluating legalization impacts, and cannabis users interested in sleep effects.

What the researchers found

Recreational cannabis laws reduced sleep by 5.37 minutes per night (99% CI: 0.91-9.83), primarily by delaying sleep onset by 7.14 minutes without changing wake times. Medical cannabis laws had no significant sleep effects.

Why it matters

Global sleep duration is declining with significant health consequences. If cannabis legalization further reduces sleep — even by a few minutes — the population-level health impact could be substantial across millions of people.

The numbers in context

175,493 respondents, 2003-2021. Recreational laws: -5.37 min sleep (99% CI: 0.91-9.83), +7.14 min later bedtime (99% CI: 3.12-11.16). Effects concentrated in males and ages 25+.

How the study worked

Two-way-fixed-effects difference-in-differences regression analyzing American Time Use Survey data from 175,493 respondents aged 18-65 from 2003 to 2021.

What this study cannot tell us

Time use data measures sleep opportunity, not actual sleep quality. Cannot identify mechanism (direct pharmacological vs. behavioral). Small effect size may not be clinically significant individually.

How to read the evidence

Large sample with robust difference-in-differences methodology spanning 18 years of data — strong causal inference design.

When this study was published

Recent analysis using nearly two decades of time use data to capture legalization effects on sleep patterns.

The bigger picture

Five minutes of lost sleep sounds trivial individually, but at the population level across tens of millions in legal states, the cumulative health impact could be meaningful. This adds to the growing picture of legalization's broader lifestyle effects.

Questions still open

Is the sleep reduction due to cannabis use itself or lifestyle changes associated with legalization? Does the sleep timing shift matter more than total duration?

Common questions

Does cannabis help or hurt sleep?

This population-level study found recreational legalization reduced sleep duration by about 5 minutes per night. Individual effects vary, but at the population level, legalization appears to slightly reduce sleep.

Why only recreational and not medical cannabis laws?

Medical cannabis laws affect a much smaller population and typically involve different usage patterns. Recreational legalization leads to broader population-level behavior changes that are more detectable in large surveys.

Read the original research

The Effects of Cannabis Access Laws on Sleep in the U.S.

AJPM focus, 4(5), 100387

View on PubMed ↗Publisher’s paper ↗

Citation

Xu, Carol; Sturman, Zachary. (2025). The Effects of Cannabis Access Laws on Sleep in the U.S.. AJPM focus, 4(5), 100387. https://doi.org/10.1016/j.focus.2025.100387