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Self-Reporting Adolescent Drug Use is Either Hide or Hair

Self-reporting of substance use among adolescents can be problematic. Combining with hair analyses, researchers say, provided a fuller, truer picture. Courtesy image by U.S. Preventive Services

At the end of last year, the National Institute on Drug Abuse said substance use (illicit drugs, nicotine, cannabis, alcohol, etc.) among adolescents had held steady after significantly declining in 2021.

That was modestly good news, but still worrisome, given that 11% of eighth graders, 21.5% of 10th graders and 32.6% of 12th graders said they had used some form of substance in the past year.

For researchers at UC San Diego School of Medicine, with colleagues elsewhere, there was an additional underlying concern and question: Just how accurate are these numbers, given that they are self-reported by adolescents?

In a new study, published February 22, 2023 in The American Journal of Drug and Alcohol Abuse, the answer was not so much. Or at least not by those self-reported numbers alone.

The researchers, led by first author Natasha E. Wade, PhD, assistant professor, and senior author Frank Haist, PhD, both in the UC San Diego and SDSU Joint Doctoral program in Clinical Psychology, looked at hair samples from 1,390 children, ages nine to 13, who are part of the ongoing Adolescent Brain Cognitive Development Study, a long-term assessment of brain development and child health involving nearly 12,000 children across the country.

Researchers asked the sampled children whether they had taken drugs in the last year, and then analyzed hair samples to confirm whether recent drug-taking had occurred.

Of the children who were asked if they had taken drugs, 10% agreed that they had. Hair analyses confirmed that 10% of adolescents overall tested positive for at least one drug, with 6.1% specifically testing positive for cannabinoids, 1.9% for alcohol, 1.9% for amphetamines and 1.7% for  cocaine.

However, the children who self-reported drug-taking were not the same as those who tested positive through hair samples. In fact, of the 136 cases who self-reported any substance use and 145 whose hair samples were positive for any drug, there were only 23 matched cases.

Most importantly, hair-drug analysis revealed an additional 9% of substance use cases over and above self-reporting alone, nearly doubling the number of identified substance users to 19%.

“A long-standing issue in substance use research, particularly relating to children and adolescents, is a reliance on self-reporting, despite the known limitations to the methodology, said Wade. “When asked, children may mis-report (unintentionally or intentionally) and say they take drugs when they don’t, or conversely deny taking drugs when they actually do.

“But rather than scrap self-reporting of drug use altogether, a more accurate picture of teenage substance use can be gained by measuring both (self-reporting and hair analyses). Self-reporting has its own strengths: For instance young people may be more willing to disclose substance use at a low level, but are less likely when frequent drug-taking patterns emerge.

“Conversely, hair assays are not sensitive enough to detect only one standard drink of alcohol or smoking one cannabis joint. The method is better at detecting frequent and moderate to heavy drug use. Combining both methodologies is vital to accurately determine the levels of substance use in the teenage population.”

Scott LaFee