Adverse effects of cannabis on health: an update of the literature since 1996.
Harold Kalant
Progress in neuro-psychopharmacology & biological psychiatry August 2004 DOI: 10.1016/j.pnpbp.2004.05.027 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Key findings | The reviewed evidence indicates that regular heavy cannabis use carries significant risks, including a causal role in accidents, airway inflammation and cancer risk proportional to amount used, and a probable causal role in precipitating schizophrenia. Cannabis dependence occurs in about 7-10% of regular users, with early and frequent use predicting dependence. Acute cognitive impairment is clear, but permanent effects in adult heavy users remain undecided, while subtle, apparently permanent effects on memory, information processing, and executive functions appear in offspring of women who used cannabis during pregnancy. |
Abstract
Recent research has clarified a number of important questions concerning adverse effects of cannabis on health. A causal role of acute cannabis intoxication in motor vehicle and other accidents has now been shown by the presence of measurable levels of Delta(9)-tetrahydrocannabinol (THC) in the blood of injured drivers in the absence of alcohol or other drugs, by surveys of driving under the influence of cannabis, and by significantly higher accident culpability risk of drivers using cannabis. Chronic inflammatory and precancerous changes in the airways have been demonstrated in cannabis smokers, and the most recent case-control study shows an increased risk of airways cancer that is proportional to the amount of cannabis use. Several different studies indicate that the epidemiological link between cannabis use and schizophrenia probably represents a causal role of cannabis in precipitating the onset or relapse of schizophrenia. A weaker but significant link between cannabis and depression has been found in various cohort studies, but the nature of the link is not yet clear. A large body of evidence now demonstrates that cannabis dependence, both behavioral and physical, does occur in about 7-10% of regular users, and that early onset of use, and especially of weekly or daily use, is a strong predictor of future dependence. Cognitive impairments of various types are readily demonstrable during acute cannabis intoxication, but there is no suitable evidence yet available to permit a decision as to whether long-lasting or permanent functional losses can result from chronic heavy use in adults. However, a small but growing body of evidence indicates subtle but apparently permanent effects on memory, information processing, and executive functions, in the offspring of women who used cannabis during pregnancy. In total, the evidence indicates that regular heavy use of cannabis carries significant risks for the individual user and for the health care system.
Comparable studies
Other narrative reviews on cannabis, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Causal association between cannabis and psychosis: examination of the evidence | 2004 | Review | |
| Cannabis sativa: A comprehensive ethnopharmacological review of a medicinal plant with a long history. General (historical and pharmacological review) | 2018 | Review | |
| Psychiatric effects of cannabis | 2001 | Review | |
| Beyond THC: The New Generation of Cannabinoid Designer Drugs | 2011 | Review | |
| Cannabidiol, a Cannabis sativa constituent, as an antipsychotic drug | 2006 | Review |
Citations in the library
Cited by 9
- Latent inhibition, aberrant salience, and schizotypy traits in cannabis users Schizophrenia Research: Cognition January 5, 2022
- Cannabis, Cigarettes, and Their Co-Occurring Use: Disentangling Differences in Gray Matter Volume. The International Journal of Neuropsychopharmacology June 4, 2015
- New synthetic drugs in addictovigilance. The´rapie 2015
- Acute intoxication caused by a synthetic cannabinoid in two adolescents. The journal of pediatric pharmacology and therapeutics : JPPT : the official journal of PPAG April 2012
- Nabilone produces marked impairments to cognitive function and changes in subjective state in healthy volunteers. Journal of Psychopharmacology November 2010
and 4 more in the library
Cites 6
- Psychiatric effects of cannabis The British Journal of Psychiatry February 1, 2001
- Cannabis‐induced Koro in Americans Addiction November 1, 2001
- Cannabis-induced psychosis: a cross-sectional comparison with acute schizophrenia. Acta Psychiatrica Scandinavica March 1, 2002
- Cannabis use and psychosis: a review of clinical and epidemiological evidence. Australian & New Zealand Journal of Psychiatry February 1, 2000
- Cannabis psychosis and acute schizophrenia. a case-control study from India. European Addiction Research June 1, 1999
and 1 more in the library