Why Are Adult ADHD Cases Climbing?

The prevalence of adult-onset ADHD may be surprisingly high—and seemingly rising—but this may only be due to how the condition was previously underdiagnosed. In fact, one expert believes the recent jump in adult ADHD diagnoses is underwhelming relative to the true rate of cases.

In an interview with HCPLive during the American Academy of Physician Associates (AAPA) 2024 Conference & Expo in Houston, TX, last week, Julie Thomas, MS, DMSc, PA-C, Julie Thomas, MS, DMSc, PA-C, director of curriculum and associate professor at the University of Nevada Reno School of Medicine PA Studies Program, explained how adult ADHD is a persistent condition in the US despite limited diagnostics. The discrepancy, Thomas said, can be explained on trends of adults self-medicating to manage their longtime condition, or other comorbidities shielding its prevalence from diagnosing clinicians.

What’s more, adult patients are limited by lacking diagnostic tools including a disease severity scale—such as that available for pediatric ADHD—as well as US guidelines for the treatment of adult ADHD.

“However, the US guidelines are hopefully going to come out in the next year or so, and I think that will really help clinicians and primary care clinicians specifically to diagnose and treat ADHD,” Thomas said. “I do know that the recommendations are going to be discuss how to treat these patients—because we do know if they're not treated, they're at risk for developing comorbid psychiatric conditions.”

Because of a high prevalence of depression, anxiety and other psychiatric conditions in adults with previously untreated ADHD, the treatment initiation strategy can be nuanced. Thomas said data primarily supporting starting “low and slow” with standard stimulant therapy while trying to identify the right regimen for the patient.

“We have 2 drug compounds that we use: amphetamines and methylphenidate,” Thomas explained. “From those compounds, there are 30 medications that we can choose from. And there's different formulations, there's different release formulations, and there's different delivery methods. So, the treatment for ADHD can actually be a little nuanced. And you have to understand what your patient needs as you're treating them.”

Though the management of adult ADHD may not significantly differ from pediatric-based strategies, the former cohort comes with more intricacies in care. Thomas said adult patients are often living with symptoms of ADHD for so long that their perception of adequate treatment of it may be skewed.

“They may not notice a difference right away, or they may notice really bad side effects that alter the way that they think about treatment, and then they don't want to do treatment anymore,” Thomas said. “So, sometimes those preconceived conceived notions about treatment can affect how well we're able to treat adults.”

References

1. ^{Song P, Zha M, Yang Q, Zhang Y, Li X, Rudan I. The prevalence of adult attention-deficit hyperactivity disorder: A global systematic review and meta-analysis. J Glob Health. 2021;11:04009. Published 2021 Feb 11. doi:10.7189/jogh.11.04009}
2. ^{Riglin L, Todd A, Blakey R, et al. Young-Adult Social Outcomes of Attention-Deficit/Hyperactivity Disorder. J Clin Psychiatry. 2023;84(2):22m14379. Published 2023 Jan 25. doi:10.4088/JCP.22m14379}