Mind Over Marijuana: What Pot Really Does to Your Brain

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Sorry, folks, pot is still an illegal substance in America. The U.S. Drug Enforcement Administration (DEA) recently doubled down on keeping it that way for the foreseeable future. But Uncle Sam's announcement wasn't entirely a buzzkill. The DEA did agree to lift restrictions on pot growing for research purposes, allowing sanctioned scientists to grow weed in their labs. Prior to this, the University of Mississippi was the only federally sanctioned distributor for cannabis for research.

What does this mean for you weed-toting residents of Colorado, Washington, or card-carrying smokers in California? Well, researchers will finally be able to get a real grasp on how impactful marijuana is for pain; why we get the munchies; how different strains work on the body; and what, exactly it is doing to our brains. But good research takes time (think, years). For now, here's what we know about pot and its impact.

Short-Term Changes

The major player in marijuana is tetrahydrocannabinol (THC). When a person smokes, THC gets into the bloodstream quickly, where it activates receptors that are part of our natural endocannabinoid system. THC basically floods this system, which can lead to hallucinations and reduced anxiety. In some people, it can also lead to negative feelings, such as distress, anxiety, and depression.

Then there are the cannabidiols (CBD), which can also help to reduce anxiety. Dr. Joe McSherry, neurologist at the University of Vermont and expert on medical cannabis research says that CBD with THC is the best medical combination for treating neuropathic pain through cannabis. He says this duo is basically enhancing what the endocannabinoid system already does, which is to encourage the body to "kick back and heal."

McSherry says researchers haven't quite unlocked why marijuana can result in time sense distortions or the munchies. Given the time at which people report the munchies, it's possible that the drop of THC blood levels somehow creates these cravings.

A central point of marijuana's short-term impact, emphasizes McSherry, is that there is no physical harm done to the brain.

Long-Term Use

There has been a lot of research put out over the years warning us that using cannabis can harm intelligence, particularly if it's used during adolescence. One major study, published in Proceedings of the National Academy of Sciences in 2012 found that, among a group of 1,037 people born in 1972 and 1973, persistent cannabis use was linked to declines in intelligence. Specifically, they found that frequent use of pot that began in adolescence was associated with a loss of 8 IQ points. People who used marijuana heavily beginning in adulthood did not experience these same losses. McSherry takes issue with this study because he says there are many other factors that could influence this relationship, including socioeconomic standing and mental health.

A better set of studies, according to McSherry, are two that looked at groups of over 6,000 people from England, born in 1958 and 1970. Both studies showed that people who have higher IQs were more likely to use drugs and that people who use drugs generally do better later in life. These findings looked at many drugs in addition to cannabis, including cocaine, ecstasy, and amphetamines. McSherry points out that the conclusion here is not that drugs make a person smarter or more successful. It is likely, instead, that people who have higher levels of education are more likely to have high IQs, be successful, and use drugs, whether because of expendable money or access to drugs at college.

In the long term, McSherry says that research backed by a highly motivated war on drugs has yet to show marijuana use is dangerous. "Minimizing drug use is a noble goal and I would not encourage anyone to use drugs. Certainly alcohol kills kids who drive," says McSherry. "[But] I have seen no credible data to suggest cannabis adversely affects the brain." Adolescent use of pot is not something to ignore, but McSherry believes that, instead of focusing on drug use as the issue, people should be more focused on why young people are using the drug in the first place.

The Promise of Medical Pot

Medical marijuana has already generated a lot of buzz as a treatment for chronic pain and cancer. Specifically, research over the decades has shown that pot may target brain tumors, called gliomas. Other areas for use that researchers are investigating include rabies, tetanus, and epilepsy. The most positive effects, says McSherry, may come from older people trying out cannabis, particularly to treat sleep, anxiety, and inflammation. But most of these are theoretical. In the world of pot research today, there are still more questions than answers.