Prevention Works!

Telling the Truth About Marijuana

Recently reported findings from SAMHSA’s National Household Survey on Drug Abuse show a marked increase of drug use among 12- to 17-year-olds, mostly due to higher rates of marijuana use. This annual survey provides estimates of the prevalence of illicit drug, alcohol, and tobacco use and monitors trends over time.

The survey’s principal findings involving marijuana include:

• Current use of marijuana increased from 7.1 percent in 1996 to 9.4 percent in 1997. Marijuana use among youth has almost tripled from 1992 to 1997.
• The percentage of youth reporting that they perceived a risk from smoking marijuana once or twice a week decreased from 57.1 to 54 percent.
• In 1997, more than half of 12- to 17-year-olds reported that marijuana was easy to obtain.
• Fifteen percent of youth reported being approached by someone selling drugs during the 30 days prior to the interview.

As these findings show, marijuana use is on the rise. Prevention can counter this increase. One important prevention approach is to teach children the truth about marijuana and its effects on their health. The National Institute on Drug Abuse (NIDA) has published a tool kit that details the health effects of marijuana and includes teaching tools and activities to explain those effects to children.

The reality of marijuana use:

• THC, the main ingredient in marijuana, binds to and activates receptors in the brain, known as cannabinoid receptors. Many of these control memory, thought, concentration, time and depth perception, and coordinated movement.
• By activating these receptors, THC interferes with the normal functioning of the part of the brain most responsible for balance, posture, and coordination of movement.
• The hippocampus, which is involved with memory formation, also contains many cannabinoid receptors. Marijuana affects memory by activating cannabinoid receptors in the hippocampus and decreasing the activity of neurons in this area.
• The effect of marijuana on long-term memory is less certain. Research studies have shown that THC can permanently damage the hippocampus of rats, suggesting that marijuana use can lead to permanent memory impairment.
• Marijuana interferes with the receipt of sensory messages--for example, touch, sight, hearing, taste, and smell--in the cerebral cortex. Marijuana activates cannabinoid receptors in these areas of the cerebrum and results in the brain misinterpreting nerve impulses from the different sense organs.

For more information on the dangers of marijuana use, contact the National Clearinghouse for Alcohol and Drug Information, PO Box 2345, Rockville, MD 20847-2345; 800/729-6686; TDD 800/487-4889; http://ncadi.samhsa.gov.

Source: NIDA Goes to School Tool Kit, NIH Pub. No. 98-3592. Reprinted 1998.

To receive a complimentary copy of this PreventionAlert, call SAMSHA's National Clearinghouse for Alcohol and Drug Information (NCADI) @ 1-800-729-6686, TDD 1-800-487-4889 (for the hearing impaired.) PREVENTIONAlert is supported by the Center for Substance Abuse Prevention of the Substance Abuse and Mental Health Services Administration, and may be copied without permission with appropriate citation. For information about PREVENTIONAlert, please contact CSAP by phone (301) 443-0581 or e-mail gensley@samhsa.gov