Research highlights changing trends in ADHD diagnoses among adolescents and adults

New research identifies differing trends in attention-deficit/hyperactivity disorder (ADHD) diagnoses among adolescents and adults, including an increase among adults from 2020 to 2023. The study, published in the American Psychiatric Association Journal Psychiatric Research and Clinical Practice, found a significant downward trends in ADHD incidence among adults from 2016 to 2020 and adolescents from 2016 to 2018. The ADHD incidence rate remained stable for adolescents in subsequent years.

ADHD is a neurodevelopmental disorder involving inattention and/or hyperactivity and impulsivity that interferes with a person's functioning and ability to perform daily activities, including at school or work. ADHD is often viewed as a condition primarily impacting childhood and adolescence; however, it can also affect adults. Research on the prevalence of ADHD in adults remains limited, with findings varying considerably.

The large retrospective cohort study, conducted by researchers at Saint Louis University and SSM Health, involved more than 140,000 adolescents and adult patients who used services with a large healthcare system located in four states. New ADHD diagnoses were identified using patient charts. Regression analysis was used to determine incidence rates and trends in ADHD diagnoses by age group.

They found a significant downward trend in ADHD incidence among adults from 2016 to 2020 and an upward trend from 2020 to 2023. Among adolescents, a significant downward trend was observed between 2016 and 2018, and the incidence rate remained stable between 2018 and 2023. 

"Fluctuations in incidence rates are likely due to a complex interplay of various factors," the authors write. For example, increased awareness and destigmatization of ADHD can lead to more diagnoses. Changes in diagnostic criteria, such as the expansion of ADHD criteria in the DSM-5 compared to previous editions, may have contributed to an increase in diagnoses. Variations in diagnostic practices and assessment methods can contribute to differences in incidence rates. In addition, there are some indications, the authors note, that the COVID-19 pandemic may have contributed to new ADHD diagnoses and worsening symptoms.

The authors suggest that this research can support future efforts to identify modifiable risk factors, ensure sufficient treatment resources, develop targeted interventions, and address diagnostic disparities. The study authors include Margaret L. Paul, M.S., Poorva Sheth, B.S., Regan Davis, B.S., Timothy Chrusciel, M.P.H., Erick Messias, M.D., M.P.H., Ph.D.