Rising ADHD medication use, persistent gaps in treatment

ADHD is highly prevalent, diagnosed in ∼3% of adults¹ and ∼8% of youth.² By definition, it is associated with functional impairment across academic, occupational, and social domains. The consequences are debilitating—and in some cases, disastrous—including elevated risk of homelessness and suicide³ and a 6–8 year shorter life expectancy.⁴ The financial toll is staggering, with total costs estimated at up to €18.67b in high income nations. Effective treatment is essential to ameliorate these negative outcomes and costs. Whereas the beneficial effect of behavioral interventions are limited in blinded evaluation of ADHD symptoms,⁵ medications, especially stimulants, are among the most effective treatments in child psychiatry.³ Yet, access to ADHD medications remains restricted. Many individuals do not have access to, or underutilize, services due to a convergence of obstacles. These include community-level (e.g., cultural norms, poverty), individual-level (e.g., beliefs, health status, and knowledge), and interpersonal (e.g., social support) factors,⁶ all compounded by challenges faced by health professionals, such as lack of knowledge, resources, or training, stigma, and fragmented care pathways.⁶

Available knowledge on medication use trends concerns prevalence and mainly focuses on youth, typically limited to data from a handful of nations. Li and colleagues⁷ address this gap by estimating both incidence and prevalence of ADHD medication use between 2010 and 2023 across five countries—Belgium, Germany, the Netherlands, Spain, and the UK—using electronic health records from individuals aged 3 years and older. Use was estimated for five ADHD medications, comprising three stimulants (methylphenidate, dexamphetamine, and lisdexamfetamine) and two non-stimulants (atomoxetine and guanfacine). Across countries, incidence and prevalence increased, with prevalence more than doubling in the Netherlands and tripling in the UK. Among children, patterns varied: prevalence rates increased in Belgium and the UK but rose and subsequently declined in the Netherlands and Spain. Among adolescents and adults, medication use increased consistently, and this trend was especially pronounced in adults and females with ADHD. For instance, adults aged 25 and older in the UK showed a dramatic surge: a fifteen-fold increase in males and a twenty-fold increase in females.

Although the apparent increase could be interpreted as alarming or as evidence of excessive prescribing, a contextualized interpretation suggests not only improved recognition but also that many individuals who could benefit from medication are still not treated. The pronounced increase in adult medication use indicates that clinical practice follows major research trends. ADHD was once considered a childhood-limited condition; diagnostic methods and development of treatments for adults lagged behind those of children.⁸ However, ADHD in adults is now an accepted phenomenon,⁸ supported by changes to diagnostic criteria and wording, and rapidly expanding empirical evidence.⁸ Similarly, the accelerated increase in females also signals that findings from research are taken up by practice. ADHD symptoms in females may be less disruptive and this contributes to delayed diagnosis and treatment in females who, because of such delays, bear a higher burden of comorbid psychiatric conditions and health care utilization.⁹ Although the sex gap in treatment is narrowing, Li et al. show the incidence of ADHD medication use remains three times higher among males.

Comparing ADHD prevalence with medication use highlights that treatment uptake is below the rates recommended.¹⁰ Even with increased prevalence use of 0.23–1.56%, if ADHD affects ∼8% of youth,² then 80.5% of diagnosed individuals are not on an ADHD medication in the highest treated country and 95.1% in the lowest treated country, consistent with substantial unmet needs for ADHD medication treatment.¹⁰

Continuation rates are alarmingly low. One year after initiating pharmacotherapy, across countries, 15–44% of patients were covered by treatment, when applying a 30-day grace period (33–57% applying a 90-day grace period), with coverage dropping at two years to 8–30%. Certainly, there are individual-level and ADHD-specific factors related to discontinuation, but the observed variability across countries indicates health system-level factors also play a role. Identifying these determinants is essential for improving adherence rates.

Among individuals who initiated ADHD medication use, females and older persons were more likely to exhibit a greater number of comorbidities and use other medications including antipsychotics, anxiolytics, hypnotics, and sedatives. This implies that females and older individuals who initiate treatment may present with a more complex and/or impairing clinical profile. These findings have important implications for the design of clinical trials. Given that those with comorbidities and/or concurrent medication use are usually excluded from clinical trials, knowledge of the effectiveness and safety of ADHD medications for females and older persons—precisely those who appear more clinically complex—is comparatively limited.

Contributors

NB: Conceptualization, Writing—Original Draft, Writing—Review & Editing.

NP: Conceptualization, Writing—Review & Editing.

Declaration of interests

The Authors declare no biomedical or financial conflicts of interest.