Abstract
BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) has been shown to pose considerable clinical and economic burden; however, research quantifying the excess burden attributable to common psychiatric comorbidities of ADHD among pediatric patients is scarce. This study assessed the impact of anxiety and depression on healthcare resource utilization (HRU) and healthcare costs in pediatric patients with ADHD in the United States. METHODS: Patients with ADHD aged 6-17 years were identified in the IQVIA PharMetrics Plus database (10/01/2015-09/30/2021). The index date was the date of initiation of a randomly selected ADHD treatment. Patients with ≥ 1 diagnosis for anxiety and/or depression during both the baseline (6 months pre-index) and study period (12 months post-index) were classified in the ADHD+anxiety/depression cohort; those without diagnoses for anxiety nor depression during both periods were classified in the ADHD-only cohort. Entropy balancing was used to create reweighted cohorts. All-cause HRU and healthcare costs during the study period were compared using regression analyses. Cost analyses were also performed in subgroups by comorbid conditions. RESULTS: The reweighted ADHD-only cohort (N = 204,723) and ADHD+anxiety/depression cohort (N = 66,231) had similar characteristics (mean age: 11.9 years; 72.8% male; 56.2% had combined inattentive and hyperactive ADHD type). The ADHD+anxiety/depression cohort had higher HRU than the ADHD-only cohort (incidence rate ratios for inpatient admissions: 10.3; emergency room visits: 1.6; outpatient visits: 2.3; specialist visits: 5.3; and psychotherapy visits: 6.1; all p < 0.001). The higher HRU translated to greater all-cause healthcare costs; the mean per-patient-per-year (PPPY) costs in the ADHD-only cohort vs. ADHD+anxiety/depression cohort was $3,988 vs. $8,682 (p < 0.001). All-cause healthcare costs were highest when both comorbidities were present; among patients with ADHD who had only anxiety, only depression, and both anxiety and depression, the mean all-cause healthcare costs were $7,309, $9,901, and $13,785 PPPY, respectively (all p < 0.001). CONCLUSIONS: Comorbid anxiety and depression was associated with significantly increased risk of HRU and higher healthcare costs among pediatric patients with ADHD; the presence of both comorbid conditions resulted in 3.5 times higher costs relative to ADHD alone. These findings underscore the need to co-manage ADHD and psychiatric comorbidities to help mitigate the substantial burden borne by patients and the healthcare system.