The characteristic marijuana "high" generally consists of several phases. When smoked, the initial psychological effects of this drug take between five and 10 minutes to emerge. These effects can be described as stimulating while being relaxing at the same time. Users then describe the overcoming feeling of being calm and worry-free. The later effects tend to make the user thoughtful and serene. Marijuana can also cause rapid mood changes. A period of uncontrollable laughter followed by thoughtful silence is not uncommon. These effects -- which actually attract people to marijuana -- can last anywhere from 30 minutes to more than four hours depending on factors such as frequency of use, tolerance of the user, potency of the marijuana itself and the amount smoked.
Many students believe that marijuana is a "soft" drug or not a drug at all. People always say, "It's only weed," or "Nobody ever died from smoking weed." Marijuana smokers assume that if people cannot die directly from smoking weed, "it can't be bad for you." True, the direct effects of marijuana make it nearly impossible to overdose from, but there are various properties that point to it being far from harmless.
Let me describe how marijuana works in the body and then explain how it affects common activities like driving and taking an exam. There are more than 400 substances in marijuana, with 61 unique chemicals called cannabinoids. One chemical in particular, delta-9-tetrahydrocannabinol (THC), is the most active ingredient. When smoked, THC is rapidly absorbed into the blood and distributed to the brain. The remaining THC is absorbed and stored by the fatty tissues in the body. It slowly trickles out of these tissues, back into the bloodstream, thus consequently still affecting the brain.
Since about 35 percent of the brain consists of fat, THC gets absorbed and stays here as well. THC has a half-life of 19 hours, meaning that in 19 hours, half the amount of THC will remain in the blood. Metabolites from THC are also formed in the liver and have a half-life of 50 hours.
In the brain, THC binds to specific sites (cannabinoid receptors) which directly inhibit memory, thought, concentration, time and depth perception, and coordinated movement. What's the big deal, right? Well, many fellow students have said to me, "I never drink and drive but I smoke weed and drive because I drive slower and I am safer." Statistics speak strongly against this, however.
In a telephone survey of nearly 6,000 students, respondents who reported driving six or more times per month after smoking marijuana were 2.4 times more likely to be involved in traffic accidents than those who did not smoke marijuana before driving. Marijuana sharply affects many skills required for safe driving: alertness, concentration, coordination and reaction time. Marijuana use can also make it difficult to judge distances and react to signals and sounds on the road. Alarmingly, these side effects persist long after the user has experienced the "high."
The effects of marijuana on thought, concentration, and memory are detrimental to one's academic performance as well. These effects can last more than 24 hours after smoking marijuana, so it is not surprising when students say to me: "I feel much slower for days after I get high." More importantly, it may take several weeks for a chronic smoker to get truly sober. Since marijuana affects memory and is in the system for so long after smoking, it can impair your test-taking ability or reduce your analytical reasoning skills when writing a paper even when you do not realize it. A recent survey of college students indicates that non-smokers had statistically significant higher grade point averages than frequent smokers.
A number of studies have been conducted about marijuana as a gateway drug. I'm not suggesting that just because you smoke marijuana, you're definitely going to use different drugs. This would be quite misleading. Smoking marijuana puts one in contact with people who use other drugs, thus increasing your contact and access to other drugs.
Long-term studies of students and their patterns of drug use show that very few young people use other illegal drugs without first trying marijuana. For example, the risk of using cocaine is 104 times greater for those who have tried marijuana than for those who have never tried it. Scientists are also studying the possibility that long-term marijuana use may create chemical changes in the brain that make a person more at risk for becoming addicted to other drugs, such as alcohol or cocaine.
I want to urge you to think about what you do when smoking marijuana as well as the way it affects the body. In addition to these risk-factors, there is also a possibility that marijuana can be laced with other drugs like PCP or cocaine. No one checks to see if marijuana meets some kind of health standard. In the words of a fellow student: "This one time I got high, I was high for hours and I felt really speedy. I got nothing done the entire day because I was so paranoid." It is likely that this student's marijuana was mixed with some other drug. Given this added risk, it is not surprising that the National Institute of Drug Abuse (http://www.nida.nih.gov) reports an increase in marijuana-related emergency room visits over the last six years. If you are not concerned about what you put in your body, then who else is going to care? I doubt that a drug dealer will ever say, "You might not want this -- it's bad for you."
