(Reuters Health) - Teens on Native American reservations continue to be more likely to report using alcohol, marijuana and other illicit drugs than peers elsewhere in the U.S. and to start using at younger ages, a recent study suggests.

Researchers examined survey data on alcohol and drug use for 1,660 students in grades 8, 10 and 12 who self-identified as Native American and attended schools on or near reservations during the 2016 to 2017 academic year, and compared their responses to results for U.S. youth in general on similar surveys.

When researchers looked at what proportion of the participants reported using various substances within the past month, the disparity between Native and other youths was greatest in the eighth grade.

Native American eighth graders were more than four times as likely to use alcohol and more than twice as likely to use marijuana or other illicit drugs in the previous month. Native American eighth graders also had more than triple the risk of binge drinking and more than quadruple the risk of smoking cigarettes.

“Given the much higher Native American 8th grade rates, compared to national rates, these data underscore that Native American youth begin using substances at much earlier ages than the general population,” said study co-author Randall Swaim, a psychology researcher at Colorado State University in Fort Collins.

“Other research we are conducting indicates an increased likelihood for risky patterns of later substance use when initiation of alcohol or marijuana begins at age 12 or under,” Swaim said by email.

The harms associated with high rates of use and early initiation of drinking, smoking, and using drugs for Native American youth include increasing rates of use in adulthood, higher risk of developing addiction, more alcohol-related problems and higher odds of dying from alcohol use, Swaim and co-author Linda Stanley, also of Colorado State University, write in JAMA Network Open.

In eighth grade, 23 percent of Native American teens reported using marijuana within the past 30 days, while 16 percent reported alcohol use, 12 percent admitted binge drinking and 11 percent smoked cigarettes.

Usage was even higher when researchers looked at lifetime prevalence of substance use for eighth graders. By this measure, 44 percent had ever used marijuana, 40 percent had consumed alcohol, 23 percent had gotten drunk and 30 percent had smoked cigarettes.

Compared with other U.S. youth, these Native American eighth graders were more than three times as likely to use marijuana, 70 percent more likely to drink alcohol, more than twice as likely to get drunk and three times more likely to smoke cigarettes.

By high school, even though substance use became more common among Native American adolescents, their risk of smoking, drinking and doing drugs relative to other U.S. teens no longer looked quite as huge. That’s because more teens nationwide experiment with alcohol and drugs in high school than earlier in adolescence.

Still, the researchers note, the significantly higher rates of drug and alcohol use among Native American teens have not changed much since a similar comparison in 2009-2012, with the exception of use of drugs other than marijuana, where the disparity between Native American and other teens has widened since the earlier study.

“The risk of higher drug and alcohol use among teens on reservations is related to a host of factors, many experienced in common with their non-reservation and non-Native counterparts,” said Spero Manson, author of an accompanying commentary and director of the Centers for Native American and Alaska Native Health and a researcher at the University of Colorado, Anschutz Medical Campus in Aurora.

Like teens across the U.S., Native American youth may experience peer pressure, uncertainty about their futures due to limited educational, social and employment opportunities and family instability, Manson said by email.

“Factors that appear to contribute to greater risk of substance use among Native American youths than their non-Native peers include racism which conveys messages of inferiority and failure which are often internalized, disruptions in the social fabric of the communities within which they live, and the widespread trauma that diminishes individual, familial, and community ability to cope with the stresses that plague these young peoples’ lives,” Manson added. “As a consequence, many Native American youth are unable to form deep, lasting attachment bonds to the key social institutions within their communities, specifically family, school, and other social elements of their communities.”

SOURCE: bit.ly/2kSA4at and bit.ly/2Hry4yZ JAMA Network Open, online May 31, 2018.