Marijuana Use

Marijuana is the most commonly used illicit drug among adolescents.  It is most often smoked in rolled cigarettes (“joints”) or in pipes, but it can also be ingested with food.   Although some youth think marijuana is not as harmful as other illicit drugs, it has both short- and long-term negative health effects.  The former include memory problems, loss of coordination, anxiety attacks, and increased heart rate (National Institute on Drug Abuse, 2009).   Possible long-term effects include respiratory problems, a weakened immune system, testicular cancer, and cognitive deficits (Hubbard, Franco, & Onaivi, 1999).   Teenagers who use marijuana are also more likely to have lower academic achievement, more delinquent behavior and aggression, and weaker relationships with parents, compared to non-users. It should be noted that determining which comes first is complicated the frequent co-occurrence of risk factors (National Institute on Drug Abuse, 2009).   

One may refer to YRBS data to identify aggregate-level benchmarks for different grade-levels, genders, and racial/ethnic groups. For example, 2009 YRBS data suggest that, among 9th graders, the prevalence of 30-day marijuana use is 15.5 percent.  

It is reasonable to expect that the percent of youth reporting marijuana use in the past 30 days will increase over time, since older youth are more likely to use it. The best way to gauge your program’s success is therefore to compare with data for the same age group from a source like the YRBS. If you find that the percent of youth who report recent marijuana use increases significantly while in your program, however, you may want to assess program design, implementation and quality of service delivery. 

By ChildTrends


Sources Cited

National Institute on Drug Abuse. (2009, July). NIDA infofax, science based facts on drug abuse and addiction: Marijuana.   Retrieved February 4, 2010, from 

Hubbard, J. R., Franco, S. E., & Onaivi, E. S. (1999). Marijuana: Medical implications [Electronic Version]. American Family Physician, 60, 2583-2593. Retrieved February 4, 2010 from