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The Health Impacts of Marijuana Use: Risks and Concerns
Introduction to Marijuana Use and Legalization
Marijuana, also known as cannabis, has seen a significant shift in its legal status and public perception over recent years. It is now legal for medicinal purposes in 30 states and for recreational use in 8 states in the U.S.1. This change has led to increased daily use and dependence among adults1. Despite its growing acceptance, the health impacts of marijuana use remain a topic of concern and debate.
Mental Health Risks Associated with Marijuana Use
Psychosis and Cognitive Impairment
Research indicates that heavy cannabis use can increase the risk of psychotic outcomes. A meta-analysis concluded that there is sufficient evidence to justify harm reduction programs due to the increased risk of psychosis associated with heavy cannabis use1. Regular use during adolescence is particularly concerning, as it doubles the risks of cognitive impairment and psychoses in adulthood3 4. Additionally, cannabis use has been linked to structural and functional changes in brain pathways involved in reward, learning, and addiction5.
Anxiety, Depression, and Dependence
Emerging data suggest that marijuana use may adversely affect the treatment of depression and anxiety. Regular use is associated with increased emergency department visits and fatal vehicle crashes1. Furthermore, around one in ten regular cannabis users develop dependence, highlighting the addictive potential of the substance3.
Physical Health Risks
Respiratory and Cardiovascular Effects
Marijuana smoking is associated with respiratory symptoms such as cough, sputum production, wheezing, and dyspnea9. The high particulate content and toxins in marijuana smoke suggest that long-term use may lead to chronic respiratory issues and obstructive lung disease9. Additionally, cannabis smoking probably increases cardiovascular disease risk in middle-aged adults, although its effects on respiratory cancer remain unclear due to the confounding factor of tobacco use3.
Pregnancy and Developmental Concerns
Marijuana use during pregnancy is a significant concern. Despite some claims of safety, there is insufficient evidence to support these assertions, and the potential risks to fetal development warrant caution1. Chronic use among young individuals may also stunt emotional growth and psychosocial maturation8.
Societal and Behavioral Impacts
Driving and Accidents
Driving while cannabis-impaired approximately doubles the risk of car crashes3. This increased risk is a significant public health concern, especially with the rising prevalence of marijuana use and its legalization.
Public Perception and Education
Public perception of the risks associated with marijuana use has decreased over the years. National surveys indicate that the perception of great risk from weekly marijuana use dropped from 50.4% in 2002 to 33.3% in 20141. This shift in perception underscores the need for better public health education regarding the potential risks of marijuana use.
Conclusion
While marijuana use is becoming more socially and legally accepted, the evidence points to several significant health risks. These include mental health issues such as psychosis and cognitive impairment, respiratory and cardiovascular problems, and increased risk of dependence and accidents. Public health education and harm reduction strategies are essential to mitigate these risks and ensure that the public is well-informed about the potential adverse effects of marijuana use.
Sources and full results
Most relevant research papers on this topic
Risks and Benefits of Marijuana Use
Marijuana use has increased in the U.S., with limited evidence on its benefits and risks, and its marketing has influenced public perception of its safety and potential harms.
Rigorous Journal
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Marijuana use is associated with harm in most health outcomes, highlighting the need for physicians and policy-makers to consider its potential harm in the context of legalization.
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Cannabis use increases the risk of accidents, can lead to dependence, and is associated with poor psychosocial outcomes and mental health in adulthood.
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Regular use of cannabis during adolescence and into adulthood can lead to dependence, increased risk of motor vehicle crashes, impaired respiratory function, cardiovascular disease, and adverse effects on adolescent psychosocial development and mental health.
Rigorous JournalHighly CitedCannabis use and mental health: risks and benefits
Cannabis use can contribute to dependence, psychoses, and cognitive impairment, while some cannabinoids may have neuroprotective properties and treat various mental health disorders.
Rigorous JournalCan we make cannabis safer?
Cannabidiol, a non-intoxicating component of cannabis, can reduce the negative effects of cannabis use, while high concentrations of THC increase the risks of addiction, psychosis, and cognitive impairment.
Literature ReviewRigorous JournalHighly CitedHealth aspects of cannabis.
Chronic marijuana use may stunt emotional growth in young people, but its long-term health effects are unclear.
Highly CitedMarijuana Use, Respiratory Symptoms, and Pulmonary Function
Long-term marijuana use is associated with chronic respiratory symptoms and adverse health effects, such as obstructive lung disease.
Systematic ReviewRigorous JournalHighly CitedCannabis Use and the Risk for Psychosis and Affective Disorders
Heavy use of high-THC/low-CBD types of cannabis increases the risk of psychosis, while evidence for mania and suicide is growing but less convincing for depression and anxiety.
Systematic ReviewHighly CitedAssociations Between Marijuana Use and Cardiovascular Risk Factors and Outcomes
Regular marijuana use may increase cardiovascular risk factors and outcomes, with THC potentially causing inflammation, lipid metabolism changes, and ischemia.
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