Making Sense of New Research: Some of the Short-Term and Long-Term Effects of Cannabis

In January 2017, the National Academies of Sciences, Engineering and Medicine published new research entitled “The Health Effects of Cannabis and Cannabinoids.” It presents nearly 100 conclusions related to the effects of smoking marijuana, from potential benefits to negative consequences, and ultimately recommends that more research be done on the topic.

The use of marijuana may actually be appropriate for some medical conditions, especially when used in a limited amount or frequency. This idea is gaining some traction among future physicians in the United States. Cannabis as Medicine Interest Group (CANMIG), a medical student organization at The George Washington University School of Medicine, is the first of its kind in the United States. The formation of this group in 2016  represents a tremendous shift in the way Western medicine regards marijuana. Abraham Benavides, founder and President of CANMIG, offered the following statement: "Today, there are many doctors and medical students who wish to learn more about medical cannabis because their patients are now bringing up the subject, but they may not know what to say. The District of Columbia and Maryland have now implemented medical marijuana programs, with DC residents even going so far as to decriminalize recreational possession via Initiative 71 in 2014. However, physician education in this taboo matter is lagging behind such abrupt changes in the law – and our patients may either be curious or self-medicating whether doctors learn about cannabinoids or not.”

Alternatively, the report finds that the use of marijuana for recreational purposes is a likely contributor to adverse outcomes for users, specifically when the potency or amount are increased. But what does this actually mean about the short term and long term effects of smoking marijuana?

THC, the active chemical in marijuana, is a natural chemical that plays a role in development and function. In excessive amounts, it causes the “high” often reported by marijuana users. Some of the short term effects include changes in mood, temporary hallucinations, increased heart rate, breathing problems, difficulty thinking and problem-solving, and impaired memory. And because marijuana has effects on attention and coordination, using this drug is also associated with an increased risk of being in a car accident.

The research also finds that some of the long term effects of marijuana use may include a reduction in thought, memory, and learning functions. It's even linked to lower birth weight during pregnancy.

According to Dr. Susan Weiss, Director of the Division of Extramural Research at the National Institute on Drug Abuse: “Marijuana is particularly risky for young people whose brains are still developing. Repeated use during adolescence increases the risk for poorer educational outcomes, addiction, impaired cognition (lower IQ) and attention, decreased motivation, and psychosis in those with a genetic vulnerability. Not everyone who uses marijuana will have problems with it—as is the case with most substances (alcohol, tobacco, and others). However, some will, and the data suggest that those who use it a lot, especially when they are young are most at risk.”

As we learn more about marijuana's potential medical benefits, we're also learning about its dangerous qualities for young recreational users. When it comes to this seemingly contradictory research, Dr. Weiss says, “I think you need to have an open mind, learn everything you can from the science, and make decisions with caution in mind."