Comorbidities and medical costs of Attention-Deficit/Hyperactivity Disorder: Analyses based on real-world evidence

Attention-Deficit Hyperactivity Disorder (ADHD) has an onset in childhood and often persists into adulthood. This thesis investigated the costs of ADHD within the healthcare system and the burden of ADHD, including conditions that often co-occur with ADHD. The research shows that ADHD is a costly disease from the perspective of the health insurances. Surplus costs of ADHD in the healthcare costs are substantial at €1,500 per person per year. Conditions co-occurring with ADHD further substantially increase healthcare costs, up to maximal €2.720 (substance abuse). In adults with ADHD, co-occurring conditions often develop before the initial (and thus late) ADHD diagnosis, leading to peak healthcare costs of €4,000 in the first year. Moreover, the research shows that across the full lifespan, psychiatric conditions like depression, anxiety, and substance abuse but also somatic conditions like cardiometabolic, sleep-related, neurological, and autoimmune diseases are much more prevalent in individuals with ADHD compared to the prevalence of these conditions in the general population. Also, we showed that ADHD is associated with an earlier onset of, for example, cardiometabolic diseases compared to their onset in individuals without ADHD. Individuals with ADHD also have more accidents and unintentional injuries across the lifespan, which especially applies to women with ADHD. Thorough assessment of the current care pathways, starting with disseminating the broad psychiatric and somatic manifestations of ADHD across the lifespan may ameliorate the burden of ADHD. Further, preventive measures may avert onset of co-occurring conditions, thereby reducing suffering of persons with ADHD and healthcare costs.