The effects of chronic marijuana use on circadian entrainment

Chronobiol Int. 2015 May;32(4):561-7. doi: 10.3109/07420528.2015.1004078. Epub 2015 Mar 24.


Animal literature suggests a connection between marijuana use and altered circadian rhythms. However, the effect has not yet been demonstrated in humans. The present study examined the effect of chronic marijuana use on human circadian function. Participants consisted of current users who reported smoking marijuana daily for at least a year and non-marijuana user controls. Participants took a neurocognitive assessment, wore actigraphs and maintained sleep diaries for three weeks. While no significant cognitive changes were found between groups, data revealed that chronic marijuana use may act as an additional zeitgeber and lead to increased entrainment in human users.

Keywords: Cannabis; circadian rhythms; entrainment; marijuana; zeitgeber.

MeSH terms

  • Adolescent
  • Adult
  • Behavior / drug effects
  • Cannabis*
  • Circadian Rhythm / drug effects*
  • Cognition / drug effects*
  • Female
  • Humans
  • Male
  • Sleep / drug effects*
  • Time Factors
  • Young Adult