Adverse health effects of non-medical cannabis use

Lancet. 2009 Oct 17;374(9698):1383-91. doi: 10.1016/S0140-6736(09)61037-0.


For over two decades, cannabis, commonly known as marijuana, has been the most widely used illicit drug by young people in high-income countries, and has recently become popular on a global scale. Epidemiological research during the past 10 years suggests that regular use of cannabis during adolescence and into adulthood can have adverse effects. Epidemiological, clinical, and laboratory studies have established an association between cannabis use and adverse outcomes. We focus on adverse health effects of greatest potential public health interest-that is, those that are most likely to occur and to affect a large number of cannabis users. The most probable adverse effects include a dependence syndrome, increased risk of motor vehicle crashes, impaired respiratory function, cardiovascular disease, and adverse effects of regular use on adolescent psychosocial development and mental health.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Accidents, Traffic
  • Adolescent
  • Adult
  • Cannabis
  • Cardiovascular Diseases / etiology
  • Central Nervous System / drug effects
  • Dronabinol / pharmacology
  • Humans
  • Lung Diseases / etiology
  • Marijuana Abuse / etiology
  • Marijuana Abuse / psychology
  • Marijuana Smoking / adverse effects*
  • Marijuana Smoking / epidemiology
  • Marijuana Smoking / psychology
  • Mental Disorders / etiology
  • Psychotropic Drugs / pharmacology
  • Young Adult


  • Psychotropic Drugs
  • Dronabinol