Teenage brains may be especially vulnerable to marijuana and other drugs

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Adolescents and teenagers who experiment with marijuana and prescription drugs are more likely to get hooked on them than young people who try these drugs for the first time when they are college-aged or older, according to a new analysis of United States federal data, writes Anahad O’Connor for The New York Times.

The research suggests that young people may be particularly vulnerable to the intoxicating effects of certain drugs, and that early exposure might prime their brains to desire them.

The findings have implications for public health policymakers, who in recent years have called for increased screening and preventive measures to reverse a sharp rise in marijuana vaping among teenagers.

The study, published in JAMA Pediatrics and led by a team of scientists at the National Institute on Drug Abuse, sought to gain a better understanding of how adolescent brains respond to a variety of recreational drugs.

According to The New York Times article published on 29 March 2021, previous research suggested that early exposure to marijuana, nicotine and alcohol might lead to faster development of substance use disorders.

But the new analysis cast a wider net, looking at the effects of nine different drugs, including opioid painkillers, stimulants, marijuana, alcohol, cigarettes, cocaine, heroin, methamphetamine and tranquilisers. The research focused on two age groups: adolescents between the ages of 12 and 17, and young adults aged 18 to 25.

Alcohol was by far the most commonly used substance in both groups: a quarter of adolescents and 80% of young adults said they had used it. About half of young adults said they had tried cannabis or tobacco. But among adolescents, that number was smaller: Roughly 15% said they had experimented with cannabis, and 13% said they had tried tobacco.

Most troubling was how many people went on to develop a substance use disorder, indicating that their experimentation had spiralled into an addiction.

The researchers found that within a year of first trying marijuana, 11% of adolescents had become addicted to it, compared to 6.4% of young adults. Even more striking was that within three years of first trying the drug, 20% of adolescents became dependent on it, almost double the number of young adults, The New York Times continues.

Adolescents who tried prescription drugs were also more likely to become addicted. About 14% of adolescents who took prescription stimulants for recreational use went on to develop a substance use disorder within one year, compared to just 4% of young adults.

And while 7% of young adults who tried opioid painkillers became addicted soon after taking them, that figure rose to 11.2% among younger users.

One possible explanation is that young people who have a greater predisposition to developing an addiction may be more likely to seek out illicit drugs at an earlier age.

Younger brains exhibit greater plasticity, or ability to change, than the relatively static brains of older individuals. As a result, drugs like cannabis are more likely to alter synaptic connections in younger brains, leading to stronger memories of pleasure and reward.

Link to the full The New York Times story below

 

National Institutes of Health material

Younger age of first cannabis use or prescription drug misuse is associated with faster development of substance use disorders

Published on 29 March 2021

A new study shows that in the time after first trying cannabis or first misusing prescription drugs, the percentages of young people who develop the corresponding substance use disorder are higher among adolescents (ages 12-17) than young adults (ages 18-25).

In addition, 30% of young adults develop a heroin use disorder and 25% develop a methamphetamine use disorder a year after first using heroin or methamphetamine.

These findings, published in JAMA Pediatrics, emphasise the vulnerability of young people to developing substance use disorders. The study was led by researchers at the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health.

“We know that young people are more vulnerable to developing substance use disorders, but knowledge is limited on how the prevalence of specific substance use disorders varies by time since first substance use or misuse among adolescents and young adults in the United States,” said Dr Nora Volkow, NIDA Director and a lead author of the analysis.

“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.”

To conduct this study, NIDA researchers analysed data from the nationally representative 2015 to 2018 National Surveys on Drug Use and Health conducted by the Substance Abuse and Mental Health Services Administration.

The researchers examined the proportion, or prevalence, of adolescents (ages 12-17) and young adults (ages 18-25) who had a substance use disorder in the past year (that is, past-year substance use disorder) at various intervals since the first time they used or misused one of nine different drugs: tobacco, alcohol, cannabis, cocaine, methamphetamine, heroin, and prescription drugs (opioids, stimulants, and tranquilisers used non-medically).

The researchers evaluated past-year substance use disorders at four timepoints since first drug use: fewer than or equal to 12 months, more than 12 through 24 months, more than 24 through 36 months, and more than 36 months.

The researchers found that the prevalence of past-year cannabis use disorder was higher for adolescents than young adults at all examined time frames since first use of the drug. For example, within 12 months since first cannabis use, 10.7% of adolescents had cannabis use disorder versus 6.4% of young adults.

Similarly, for the non-medical use of prescription drugs (opioids, stimulants, and tranquilisers), the researchers found a greater prevalence of past-year substance use disorders among adolescents than young adults at all examined time frames since first use. For example, within 12 months since first misuse of prescription drugs:

  • 2% of adolescents had prescription opioid use disorder versus 6.9% of young adults.
  • 9% of adolescents had prescription stimulant use disorder versus 3.9% of young adults.
  • 2% of adolescents had prescription tranquilizer use disorder versus 4.7% of young adults.

For alcohol and tobacco, adolescents and young adults had similar prevalence of past-year substance use disorders within 12 months of initiation, but that prevalence was higher for young adults in the subsequent time periods examined.

Estimates of cocaine, methamphetamine, and heroin use among adolescents were too small to report. However, approximately one-third of young adults developed a heroin use disorder (30.9%) and one-quarter of young adults developed a methamphetamine use disorder (24.8%) within one year after trying that drug for the first time.

The data excluded individuals who were incarcerated and individuals experiencing homelessness who are not living in shelters, possibly underestimating the prevalence of substance use disorders across the findings, authors noted.

“Research has shown that brain development continues into a person’s 20s, and that age of drug initiation is a very important risk factor for developing addiction,” said Dr Emily B Einstein, chief of NIDA’s Science Policy Branch and a co-author of the study.

“This underscores the importance of drug use prevention and screening for substance use or misuse among adolescents and young adults. Offering timely treatment and support to young people who need it must be a public health priority.”

 

Study details

Research Letter 

Prevalence of Substance Use Disorders by Time Since First Substance Use Among Young People in the US

Nora D Volkow, Beth Han, Emily B Einstein et al, and Wilson MCompton

Affiliations: National Institute on Drug Abuse, National Institutes of Health in Bethesda, United States.

JAMA Pediatrics journal article published online on 29 March 2021.

 

Abstract

Earlier age at drug initiation has been shown to be associated with faster transition to substance use disorder (SUD). However, prevalence of specific SUDs as a function of time since first substance use among young people has not, to our knowledge, been investigated.

We examined the prevalence of specific SUDs since first drug use (including tobacco, alcohol, cannabis, cocaine, methamphetamine, and heroin) or prescription misuse (including opioids, stimulants, and tranquilizers) in adolescents aged 12 to 17 years and young adults aged 18 to 25 years.

 

The New York Times story – Teenage Brains May Be Especially Vulnerable to Marijuana and Other Drugs (Limited access)

National Institutes of Health material – Younger age of first cannabis use or prescription drug misuse is associated with faster development of substance use disorders (Open access)

JAMA Pediatrics article – Prevalence of Substance Use Disorders by Time Since First Substance Use Among Young People in the US (Restricted access)

 

SEE ALSO FROM MEDICALBRIEF’S ARCHIVES

 

Prescription drug poses new threat to South African youths

Teen use of marijuana ‘concentrates’ raise addiction concerns

Young people at risk of addiction show differences in key brain region

Dental painkillers may put young people at risk of opioid addiction

 

 


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