Dear Dr. Jeff: I like to smoke a little pot now and then. Is that a problem? W.N.
Dear W.N.: An increasing body of research suggests that marijuana is neither the deadly toxin its foes portray, nor the benign herb its advocates promote. What has become clearer is this?heavy, regular use of marijuana may be more harmful and habit-forming than previously suspected.
The principal active ingredient in marijuana is delta-9-tetrahydrocannabinol, THC. Researchers have discovered THC-binding receptors throughout the body and brain, and naturally occurring THC-like endogenous cannabinoids, or endocannabinoids, which bind to these receptors.
Endocannabinoids appear to play an important role in regulating mood, appetite, pain, memory, and a variety of other sensations and functions.
Current research into these mechanisms is in part driven by the debate over medical marijuana use. For many people with AIDS, cancer, and other debilitating diseases, marijuana offers substantial relief from pain, nausea, and loss of appetite. Chronic marijuana use, however, may have harmful effects as well.
THC seems to change the way in which sensory information is processed by the hippocampus, the part of our brains' limbic system which integrates sensory inputs with emotions and motivations, all components of memory formation, and learning.
Longitudinal studies of high school students who smoke marijuana regularly do show a trend of lower academic achievement and greater behavioral problems. Of course, it may be a little tricky here to sort out cause and effect!
A much-touted study of college students is reported to show that critical skills relating to attention, memory, and learning are all impaired in people who use marijuana heavily. This study likely has several important flaws, especially around issues of matching and THC "washout."
Whatever the shortcomings of the research, however, it seems clear enough to me, for pretty obvious reasons, that getting stoned every day is likely to have a deleterious impact on one's academic performance.
There may also be other health consequences to consider. Regular marijuana use is definitely associated with depressed libido, lower sperm counts, and occasional breast enlargement in men, as well as with irregular menstrual cycles in women. Marijuana smoke contains more tar than tobacco smoke, and may be even more damaging to lung tissues. Daily users have more respiratory problems and injuries from accidents than those who smoke less often or not at all.
Smoking pot elevates your blood pressure, raises your heart rate (as much as 50 percent in the first hour), and has been shown to increase some people's risk of heart attack up to five-fold.
The question of marijuana's addictive potential remains somewhat contentious. On the one hand, more than 75 million Americans have smoked marijuana at least once and it remains the most commonly?and casually?used illicit substance across the nation. On the other hand, more than 120,000 people enter treatment each year for their marijuana dependence. More young adults enter drug treatment with a primary diagnosis of marijuana dependency than for all other drugs combined. Many commentators point out that currently available marijuana is very much more potent than it used to be, so is more likely to become abused. The THC concentration of pot today is at least eight to nine times greater than in the '70s.
Some researchers believe that some ten to fifteen percent of the population are in some manner vulnerable to the dependence-causing characteristics of marijuana and can therefore become addicted to it.
These individuals might develop cravings for the drug, and develop tolerance to its effects, needing to smoke more and more of it to reach the same high. When they stop using marijuana regularly, these individuals might develop withdrawal symptoms that could last for weeks, including reactive depressions, anxiety, anger, insomnia, or nausea.
If you have questions or concerns about marijuana use, you can always contact the Health Center or the Counseling Service. The Addictions Resource Center in Bath would be an excellent off-campus alternative. And there are many web-based sources of information, including the National Institute on Drug Abuse (www.nida.nih.gov/NIDAHome.htm, Facts on Tap (www.factsontap.org and www.drughelp.org), and Go Ask Alice (www.goaskalice.columbia.edu).
Stay informed, and take good care of yourselves!
Jeff Benson, M.D.
Dudley Coe Health Center