Such loss of coordination can be caused by smoking marijuana. And that's just one of its many negative effects. Marijuana affects memory, judgment, and perception. Under the influence of marijuana, you could fail to remember things you just learned, watch your grade point average drop, or crash a car.
Also, since marijuana can affect judgment and decision making, using it can cause you to do things you might not do when you are thinking straight—such as engaging in risky sexual behavior, which can result in exposure to sexually transmitted diseases, like HIV, the virus that causes AIDS, or getting in a car with someone who’s been drinking or is high on marijuana.
It’s also difficult to know how marijuana will affect a specific person at any given time, because its effects vary based on individual factors: a person’s genetics, whether they’ve used marijuana or any other drugs before, and how much marijuana is taken. Effects can also be unpredictable when marijuana is used in combination with other drugs.
THC is up to no good in the brain. THC finds brain cells, or neurons, with specific kinds of receptors called cannabinoid receptors and binds to them.
Certain parts of the brain have high concentrations of cannabinoid receptors. These areas are the hippocampus, the cerebellum, the basal ganglia, and the cerebral cortex. The functions that these brain areas control are the ones most affected by marijuana.
For example, THC interferes with learning and memory—that is because the hippocampus—a part of the brain with a funny name and a big job—plays a critical role in certain types of learning. Disrupting its normal functioning can lead to problems studying, learning new things, and recalling recent events. The difficulty can be a lot more serious than forgetting if you took out the trash this morning, which happens to everyone once in a while. A recent study followed people from age 13 to 38 and found