FRESH WEED WORRIES

Some THC Side-Effects Less Pleasant Than Others

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