In addition to its effects on the body, marijuana also has distinct neurological actions. The primary psychoactive chemical in marijuana is delta-9 tetrahydrocannibinol, or THC. THC content in marijuana varies greatly, which is one of the reasons why it is difficult to generalize about marijuana effects. However, THC does have certain specific actions on brain chemicals and structures. According to Alexander, "THC has been proven to affect the transferring of pain in the brain and that it "interacts with the brain's endogenous opioid system, an important system for the medical treatment of pain." For this reason, marijuana is frequently recommended as a pain relief medication ("Medical Marijuana").
Marijuana affects neurons as well as neurological receptors. The specific brain receptors sensitive to THC include CB1, CB2 and anandamide. Anandamide is "a substance naturally produced by the body that acts at the cannabinoid receptor and has effects similar to those of THC," (Alexander). Alexander also notes, "The CB1 receptor is found primarily in the brain and mediates the psychological effects of THC. The CB2 receptor is associated with the immune system; its role remains unclear." Chronic long-term use of marijuana may cause brain impairment (Alexander).
The short-term psychological effects of smoking marijuana can be extremely pleasant, which is why the drug is used recreationally. However, long-term use can lead to deleterious psychological effects and therefore the drug should be taken cautiously. Initial effects include "giddiness and euphoria, followed by sedation and pleasant tranquility," (Alexander). A "distorted sense of time" and "magical or random thinking" are other short-term effects that can potentially be experienced as pleasurable ("Marijuana Use and Its Effects). Short-term psychological effects also include "heightened sensory awareness," (Hanson, Venturelli and Fleckenstein). Because of the wide variation in types of marijuana and the doses used, the specific psychological effects differ radically and from person to person and "can vary according to the expectations of the user, the social setting, the route of administration, and previous experiences," (Hanson, Venturelli, and Fleckenstein). Some of the negative short-term effects associated with smoking marijuana include short-term memory loss, paranoia, anxiety, and self-consciousness. High doses of the drug can even lead to hallucinations and delusions (Hanson, Venturelli, and Fleckenstein).
Long-term effects from chronic use of marijuana can include anxiety, depression and other mood disorders, "decreased interest in personal appearance," and lack of motivation (Hanson, Venturelli, and Fleckenstein). Both the short-term and long-term psychological effects are highly variable, depending on the quality, type, and amount of marijuana that is used. Psychological addiction to marijuana is possible with chronic use but marijuana has not been proven to be physically addictive (Alexander).
The social psychological and sociological effects of using marijuana also depend on the local culture. Marijuana is an illegal substance, and use is sometimes stigmatized. In areas where marijuana use is common, fewer stigmas will be associated with the drug. Regardless, marijuana remains an illegal substance even in states that allow medical marijuana. Therefore, persons who use marijuana recreationally run the risk of being labeled a deviant or a criminal. Jail time for marijuana possession can create a wave of problems including financial trouble.
Although marijuana is still classified as a Schedule I substance, scientific evidence shows that the effects of marijuana are not universally negative. The potential medical benefits of marijuana have led to a revolution in how the drug is used in the United States. Polls show that as many as three quarters of all American support legalizing marijuana for medical use ("Medical Marijuana"). Approving medical marijuana nationwide would entail rescheduling the drug, as Schedule I substances have no federally recognized medicinal benefits. Regardless of its legal status, marijuana has distinct effects on the human brain, mind, and body. The effects are both short-term and long-term and vary according to user, frequency of use, and type of marijuana. Marijuana should be used with care, as its effects can be extreme for some individuals.
Alexander, Alissa. "Neurobiological Effects of Medicinal Marijuana." Retrieved Dec 9, 2009 from http://serendip.brynmawr.edu/bb/neuro/neuro02/web3/aalexander.html
Hall, Wayne. "The Health and Psychological Effects of Cannabis Use." Current Issues in Criminal Justice 6(208). 1994-1995.
Hanson, Glen R., Venturelli, Peter J., and Fleckenstein, Annette E. Drugs and Society. New York: Jones and Bartlett, 2006.
"Marijuana Use and Its Effects." WebMD. 2008. Retrieved Dec 9, 2009 from http://www.webmd.com/mental-health/marijuana-use-and-its-effects
"Medical Marijuana." Drug Policy Alliance Network. Retrieved Dec 9, 2009 from http://www.drugpolicy.org/marijuana/medical/