Misuse of medications approved to treat attention-deficit/hyperactivity disorder declined in several recent national surveys, particularly among younger adults, although millions of people continued to report misuse and a subgroup with high-frequency use had higher rates of polysubstance use, according to a rapid review published in the Journal of Clinical Psychopharmacology.
The US Food and Drug Administration requested the review to assess the prevalence, patterns, acquisition, administration routes, and health consequences of attention-deficit/hyperactivity disorder (ADHD) stimulant medication misuse among US adults. Researchers searched PubMed and PsycINFO for US-based studies published from 2004 through September 2024. Cross-sectional and longitudinal studies were eligible, and findings were summarized narratively.
The review included 64 studies described across 71 publications, including 54 cross-sectional and 10 longitudinal studies. Researchers assessed risk of bias in cross-sectional studies using the Joanna Briggs Institute Checklist for Prevalence Studies and in longitudinal studies using the Quality in Prognosis Studies tool. Nearly half of the included studies focused on university populations.
Monitoring the Future data showed that past-year misuse of Adderall, a mixed amphetamine salts product, among adults aged 19 to 30 years declined from 7.8% in 2022 to 3.7% in 2023. Past-year misuse of Ritalin, a methylphenidate product, was 1.2% in 2023, with no statistically significant change during the preceding 10 years. The National Survey on Drug Use and Health estimated that 1.4% of Americans aged 12 years and older, or 3.9 million people, misused ADHD stimulant medications during the prior year in 2023. Among adults aged 18 to 25 years, estimated past-year misuse declined from 3.7% in 2021 to 3.1% in 2023. Because of methodological changes, including the introduction of web-based interviews, estimates from 2021 onward were not directly comparable with estimates from 2019 or earlier.
Misuse was primarily oral and generally infrequent. Adults reporting past-month misuse did so for an average of 4.5 days, and 4.3% reported misuse on 20 or more days. The most frequently reported reasons for the most recent misuse episode were improving concentration and remaining alert or awake. Other reported reasons included getting high, countering the effects of other drugs or experimenting, studying, and weight loss.
Adults reporting high-frequency misuse, defined in one National Survey on Drug Use and Health analysis as misuse on at least 7 days during the previous month, were more likely than adults reporting low-frequency misuse to obtain stimulants from physicians or dealers and less likely to receive them free from friends or relatives.
Poison center data showed higher critical care and psychiatric admission rates among intentional oral, nasal, and intravenous exposures than among unintentional oral exposures. Other-substance exposure was also more common in the intentional exposure groups, and suspected suicide attempts accounted for many intentional oral exposures.
Cross-sectional national surveys showed that stimulant misuse frequently co-occurred with alcohol, cannabis, cocaine, opioids, sedatives, and other substances. Because these studies did not report the age at which each substance was first used, they could not determine whether one substance preceded another.
Longitudinal studies did not find evidence that prescribed stimulant treatment during adolescence increased the risk of later substance use disorder. Adolescent stimulant misuse was associated with later illicit stimulant use and substance use disorder symptoms.
The researchers noted that many university studies used convenience samples, had low response rates, or recruited participants from single institutions. They also noted that the reviewed literature relied exclusively on self-reported data without toxicologic confirmation. Additionally, the available longitudinal studies did not assess potential long-term neurologic or cardiovascular health effects of stimulant misuse.
“ADHD stimulant medication misuse among adults, although declining, remains a public health concern, particularly among high-frequency users. Research gaps remain, especially regarding long-term health outcomes,” wrote lead author Margaret A. Maglione of the Southern California Evidence Review Center and colleagues.
The researchers reported no conflicts of interest. The work was funded through an Agency for Healthcare Research and Quality contract with the University of Southern California. The findings and conclusions do not represent the official positions of the agency or the US Department of Health and Human Services.
