Study finds adolescents more likely to become addicted to marijuana, prescription drugs

Adolescents and teenagers who try marijuana or misuse prescription drugs are more likely to develop a substance abuse disorder than young adults who are at least 18 years old, according to a new analysis of federal data.

The study, led by researchers at the National Institute on Drug Abuse (NIDA), underscores the vulnerability of adolescents to substance abuse disorders and the importance of screening for substance misuse among younger populations.

Researchers looked at the effects of nine different drugs on adolescents from 12 to 17 and young adults from 18 to 25: tobacco, alcohol, cannabis, cocaine, methamphetamine, heroin, and prescription opioids, stimulants and tranquilizers. 

The study found that within a year of first trying marijuana, about 11 percent of adolescents had become addicted to it, compared with 6.4 percent of young adults. After three years, 20 percent of adolescents became addicted, compared with about 11 percent of young adults. 

“Though not everyone who uses a drug will develop addiction, adolescents may develop addiction to substances faster than young adults. This study provides further evidence that delaying substance exposure until the brain is more fully developed may lower risk for developing a substance use disorder,” Nora Volkow, the director of the NIDA and lead author of the analysis, said in a statement.

The numbers were similarly high among adolescents who reported prescription opioid use disorder, prescription stimulant use disorder and prescription tranquilizer use disorder. 

About 11 percent of adolescents who took prescription opioids for recreational use went on to develop a substance use disorder within one year, compared with about 7 percent of young adults. 

About 14 percent of adolescents who took prescription stimulants developed a substance use disorder within a year, compared with about 4 percent of young adults, and about 11 percent of adolescents had a prescription tranquilizer use disorder, compared with 4.7 percent of young adults.

There was not much of a difference for alcohol and tobacco. According to the study, adolescents and young adults had similar prevalence of past-year substance use disorders within 12 months of initiation, but that was higher for young adults in later years. 

As for cocaine and heroin, the number of adolescents using them was too small for researchers to draw any meaningful conclusions.

The study is based on 2015 to 2018 data from the government’s National Survey on Drug Use and Health, an annual survey that tracks substance use and mental health issues among Americans. 

The findings could have strong implications for lawmakers as more states legalize marijuana use for adults and the movement to do so at the federal level is gaining steam. Pressure is likely to build to make sure there are strong protections in place for adolescents.