Title:   Drug Proofing the Family
 Authors:   Erica Wittenberg & Jim Parker

 Publication Date:

  September 2003

 Catalog No:



Marijuana has been at the front line of the clash between youth and mainstream culture for so long now -- and so much misinformation has been told and retold about it -- that it's probably useful to start from scratch in discussing it and its potential risks.

Derived from the leaves and flowering tops of the hemp plant (Cannabis sativa), marijuana is usually rolled into cigarettes or smoked in water pipes or "bongs" or hollowed-out cigars called "blunts." Marijuana is commonly known as "weed," although "grass," "pot," and "reefer" are still common terms, too.

Two other forms of cannabis, hashish and hash oil, can be made from the plant's resin, but they're less prevalent than marijuana. What all forms of the drug have in common is tetrahydrocannabinol (THC), the main psychoactive chemical in the drug.

According to the Drug Enforcement Administration, the average potency of street marijuana in 2001 was 4.1 percent THC. That may not seem like much, but it's higher than levels of 10-15 years ago, when potency averaged around 2 percent.

That extra potency could mean extra problems for users, since THC tends to stay in the body longer than other drugs. In fact, traces of THC can be detected in urine 3-5 days after use, and for up to a month in heavy users.

Subjective effects of THC include euphoria and a mild disorientation. Other short-term effects include increased appetite and heart rate, and reddening of the eyes. Effects typically last 3-4 hours.

Probably of more concern to more parents, though, is how THC affects the brain. Recent research shows the drug affects three key brain functions:

  • Memory. Pot disrupts short-term memory and increases distractibility.
  • Motor skills. Marijuana can slow reaction time and reduce "tracking ability," which could mean serious problems for inexperienced drivers.
  • Thought. Higher-order thinking is also affected, including calculation skills and the ability to follow complex instructions.

Long-term risks of marijuana are less clear-cut, but research shows that pot poses at least some degree of risk in several areas:

  • Heart/Lungs. Since marijuana raises heart rate, it could pose a risk to people with heart problems or hypertension. And since marijuana smoke irritates lung tissue and reduces respiratory capacity, which means that long-term pot smokers could be at risk for many of the same smoking-related diseases as cigarette smokers.
  • Hormones. Marijuana lowers levels of sex hormones in both sexes. In children, such changes could affect sexual maturation and physical development.
  • Brain. Research shows that marijuana can interfere with the process by which short-term memories are encoded and stored in the brain. And even though such impairment seems to be reversible, its effects on school grades definitely isn't.

While pot's long-term effects on memory, motivation, and learning may depend largely on how much is smoked, and how often, teen users face other, special risks.

That's because the teen years are the time when kids refine the personal skills they'll rely on as adults. Successfully meeting challenges, solving problems, and coping with stress are an important part of this process. As much as anything, parents should point out the risk of diluting this important aspect of growing up with pot -- or any other drug.

Other parents worry about the so-called "amotivational" effects of marijuana: the apathy and passivity sometimes seen in heavy users. It's impossible to say whether marijuana actually causes apathy, or if depressed, apathetic people are just more likely to use it in trying to cope with their feelings, it's still important to deal with apathy whenever it rears its head.

Dealing effectively with apathy -- or any other emotional problem -- is more difficult when the underlying problem is masked by a drug. Teenagers who exhibit such symptoms need help, and drug use may not be their only problem.


Marijuana Alcohol/Downers Heroin/Narcotics Stimulants
....Cocaine/Crack Hallucinogens Inhalants Other Resources


Continue with Chapter 7: Starting Points
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This is one in a series of publications on drugs, behavior, and health by Do It Now Foundation. Check us out online at www.doitnow.org.