As marijuana becomes more accepted in modern United States society and culture, a regular marijuana might be tempted to ignore the short- and long-term effects of marijuana on his or her health. THC, or “cannabis” is the active ingredient in marijuana. This ingredient affects everyone differently and generalizations about its effects are difficult to make, but observations and research have confirmed certain broader effects.

Short Term Effects of Marijuana

Marijuana’s short-term effects are apparent and range from euphoria and a sense of calmness to anxiety. These effects are easier to predict and control with medical and other marijuana strains that are purchased in controlled dispensaries. Marijuana that is purchased from street dealers and other illicit sources is often adulterated with other drugs and substances, which likely accounts for the diversity of marijuana’s reported short-term effects.

Long Term Effects of Marijuana

Researchers are slowly gaining a greater understanding of marijuana’s long-term effects. Like tobacco smoke, marijuana smoke irritates lung and bronchial tissue, and even light marijuana users report coughing, congestion and excessive phlegm production. Marijuana smoke does not contain the same carcinogens as tobacco smoke, but researchers suspect that it comprises other carcinogens.

As marijuana is absorbed into a user’s bloodstream, he can experience increased heart rate and dilation of blood vessels, which accounts for the smoker’s common red-eyed appearance that can last for up to three hours after marijuana use. Some research into marijuana use has also suggested that marijuana can suppress a user’s immune system and cause digestion problems.

Perhaps the most significant short- and long-term effect of marijuana use is on a user’s brain and nervous system. At a minimum, marijuana has been shown to create short-term memory loss. More significantly, a 2013 Northwestern University study that users who started smoking marijuana in their teens develop structural abnormalities in the parts of their brain that control memory formation, hunger and time perception. Those abnormalities will remain for several years after a user stops smoking marijuana. This research is supported by studies showing that a person who develops a marijuana habit while he or she is young is less likely to recover cognitive brain function over time. In other words, marijuana’s adverse effects are greater on a young person’s brain that is still developing and forming neural connections that are required to make intelligent decisions as that person gets older.

Young People and Marijuana

Further, a younger person who is experiencing symptoms of depression or anxiety might experience heightened symptoms when a marijuana high wears off. Many marijuana users report feeling tired and depressed following a bout of marijuana use. There is no definitive evidence of chemical dependency on marijuana, but a behavioral addiction to marijuana is not unusual among people suffering from depression.

Marijuana users should not equate trends toward marijuana decriminalization with a conclusion that marijuana use is safe. Like all substances that affect a person’s body and brain, marijuana can be dangerous and can expose users to unknown or unanticipated risks and dangers.


If you are concerned over your or a friend’s use of marijuana and have questions about the effects of that use, please call the staff and counselors at Hired Power at 800-910-9299 for answers to your questions and concerns. We can provide the information you need to make intelligent decisions about marijuana use and its effects on your body and brain.