Abstract
BACKGROUND AND OBJECTIVE: Attention-deficit/hyperactivity disorder (ADHD) treatment rates in adults are low, possibly owing to discontinuation of pediatric care due to various circumstances (including inadequate health insurance coverage, poor disease insight, and patient/family resistance, as well as those who manage their ADHD independent of pharmacologic intervention) during the transition from adolescence to adulthood. To improve the understanding of treatment patterns during this transition, this study characterized pharmacotherapy use in patients with ADHD aged 16-21 years. METHODS: A retrospective claims analysis of the IBM(®) MarketScan(®) Commercial Databases, which represent all census regions of the USA, included patients aged 16-21 years with two or more ADHD diagnoses between 1/1/2008 and 12/31/2017 (one or more diagnoses during the year of age 17) who were continuously enrolled from ages 16-21 years and prescribed ADHD medication for ≥ 6 months at age 17 years. Pharmacotherapy use was assessed longitudinally. Comparisons between ages were conducted using Wilcoxon signed-rank tests and McNemar tests. Treatment discontinuation was estimated using Kaplan-Meier analyses. RESULTS: The analysis included 10,292 patients. The overall percentage of patients receiving pharmacotherapy significantly decreased (p < 0.001, regardless of treatment type and presence of co-occurring psychiatric disorders) as patients aged, with a median time to treatment discontinuation of 2.94 years. Among patients using pharmacotherapy at the age of 17 years, more than 30% were no longer using pharmacotherapy at age 21 years. As patients aged, the percentage using long-acting amphetamines or methylphenidates decreased, and the percentage receiving no treatment increased. The percentage of patients with disrupted treatment from age 18 to 21 years ranged from 17.9 to 24.1%. After transitioning to disrupted treatment or no treatment, low percentages of patients returned to pharmacotherapy use (disrupted treatment: 15.7-21.5% per year; no treatment, 2.7-3.8% per year). Across all age groups, statistically significantly greater (p < 0.05) percentages of patients with co-occurring psychiatric disorders used lisdexamfetamine, dextroamphetamine-amphetamine mix short acting, and non-stimulants compared with patients without co-occurring psychiatric disorders. Patients with co-occurring psychiatric disorders remained on ADHD pharmacotherapy longer and switched or augmented their pharmacotherapy more frequently than patients without co-occurring psychiatric comorbidities. CONCLUSIONS: Patients rarely reinitiated treatment after pharmacotherapy was disrupted or discontinued, emphasizing the need for increased focus on the management of ADHD as patients transition from adolescence to adulthood.