http://teens.drugabuse.gov/facts/facts_mj2.aspTHC Attaches to Specific Receptors in the Brain
THC is up to no good in the brain. THC finds brain cells, or neurons, with specific kinds of receptors called cannabinoid receptors. Then, it binds to these receptors. [4]
When it attaches to a neuron, THC interferes with normal communication between neurons. Think of it as a disruption in the phone service, caused perhaps by too many users all at once. Let's say Neuron #1 needs to tell Neuron #2 to create a new memory. If THC is in the mix, this communication is likely to fail.
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. [4]
THC Creates Learning and Memory ProblemsThe hippocampus is a part of the brain with a funny name and a big job. It's in charge of certain types of learning and memory.
Disrupting the normal functioning of the hippocampus can lead to trouble studying and learning and problems recalling recent events. The difficulty can be a lot more serious than "Did I take out the trash this morning?"
Interference with the hippocampus may also lead to lasting memory loss. Studies in rats show that taking in a lot of THC over a long period of time can damage neurons in the hippocampus. Chances are, if it happens to rats, it's happening to people who smoke marijuana. [4]
Smoking Marijuana Can Make Driving DangerousThe cerebellum is the section of our brain that does most of the work on balance and coordination. When THC finds its way into the cerebellum, it makes scoring a goal in soccer or hitting a home run pretty tough.
THC also does a number on the basal ganglia, another part of the brain that's involved in movement control.
These THC effects can spell disaster on the highway. Research shows that drivers on marijuana have slow reaction times, impaired judgment, and problems responding to signals and sounds on the road. In one study of 150 reckless drivers, 33 tested positive for marijuana. [1] [4]
Smoking Marijuana May Lead to Lung CancerThe list of negative effects goes on and on. Smoking marijuana may increase the risk of heart attack. Smoking marijuana may cause lung cancer because it has some of the same cancer-causing substances as tobacco. Plus, marijuana smokers tend to inhale more deeply and hold their breath longer than cigarette smokers do. So more smoke enters the lungs. Puff for puff, smoking marijuana may increase the risk of cancer even more than smoking cigarettes does. [4]
What About Medical Marijuana?THC, the main active ingredient in marijuana, produces effects that potentially can be useful for treating a variety of medical conditions. It is the main ingredient in a pill that is currently used to treat nausea in cancer chemotherapy patients and to stimulate appetite in patients with wasting due to AIDS. Scientists are continuing to investigate other potential medical uses for cannabinoids.
However, smoking marijuana is difficult to justify medically because the amount of THC in marijuana is not always consistent. It would be difficult-if not impossible-to come up with a safe and effective use of the drug because you could never be sure how much THC you were getting. Moreover, the negative effects of marijuana smoke on the lungs will offset the helpfulness of smoked marijuana for some patients.
Finally, little is known about the many chemicals besides THC that are in marijuana, or their possible negative impact on patients with medical conditions. [4]
