Use of Marijuana: Effect on Brain Health: A Scientific Statement From the American Heart Association
Fernando D. Testai, Philip B. Gorelick, Hugo J. Aparicio, Francesca Filbey, Raul Gonzalez, Rebecca F. Gottesman, Miriam Melis, Mariann R. Piano, Tiziana Rubino, Sarah Y. Song
Stroke February 10, 2022 DOI: 10.1161/str.0000000000000396 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Review Peer reviewed |
|---|---|
| Topics | Cannabis |
| Citations | 50 |
| Key findings | The authors argue that cannabis may adversely affect brain health and cognition, citing preclinical evidence that cannabinoids disrupt neurodevelopment, neurotransmitter release, and synaptic plasticity, plus observational links to cognitive impairment and increased stroke risk. Whether cognitive effects reverse after abstinence remains unclear. |
Abstract
Marijuana is perceived as a harmless drug, and its recreational use has gained popularity among young individuals. The concentration of active ingredients in recreational formulations has gradually increased over time, and high-potency illicit cannabinomimetics have become available. Thus, the consumption of cannabis in the general population is rising. Data from preclinical models demonstrate that cannabinoid receptors are expressed in high density in areas involved in cognition and behavior, particularly during periods of active neurodevelopment and maturation. In addition, growing evidence highlights the role of endogenous cannabinoid pathways in the regulation of neurotransmitter release, synaptic plasticity, and neurodevelopment. In animal models, exogenous cannabinoids disrupt these important processes and lead to cognitive and behavioral abnormalities. These data correlate with the higher risk of cognitive impairment reported in some observational studies done in humans. It is unclear whether the effect of cannabis on cognition reverts after abstinence. However, this evidence, along with the increased risk of stroke reported in marijuana users, raises concerns about its potential long-term effects on cognitive function. This scientific statement reviews the safety of cannabis use from the perspective of brain health, describes mechanistically how cannabis may cause cognitive dysfunction, and advocates for a more informed health care worker and consumer about the potential for cannabis to adversely affect the brain.
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 4
- Shrinking the know-do gap in psychedelic-assisted therapy. Nature Human Behaviour February 24, 2025
- Ophthalmic Effects of Recreational (“Party”) Drugs: Clinical and Translational Perspectives Journal of Clinical & Translational Ophthalmology May 12, 2026
- Self-administered complementary and alternative methods of treating mental disorders among students in Wrocław: a cross-sectional study. Frontiers in Public Health 2025
- Cannabis use by people with HIV is associated with an anti-inflammatory immunometabolic phenotype in monocyte-derived macrophages. Journal of Neuroinflammation April 17, 2026
Cites 5
- Cognitive outcomes associated with long-term, regular, recreational cannabis use in adults: A meta-analysis. Experimental and Clinical Psychopharmacology August 1, 2020
- Regular cannabis use is associated with altered activation of central executive and default mode networks even after prolonged abstinence in adolescent users: Results from a complementary meta-analysis Neuroscience & Biobehavioral Reviews 2019
- Association of Cannabis With Cognitive Functioning in Adolescents and Young Adults: A Systematic Review and Meta-analysis JAMA Psychiatry June 1, 2018
- Meta-analysis of neurocognition in young psychosis patients with current cannabis use. Journal of Psychiatric Research April 1, 2018
- Cortical neuroinflammation contributes to long-term cognitive dysfunctions following adolescent delta-9-tetrahydrocannabinol treatment in female rats. European Neuropsychopharmacology December 2015