Direct medical and indirect absenteeism costs among working adult ADHD patients in the United States.

There is a significant economic burden of ADHD in terms of direct medical (including out-of-pocket) cost as well as indirect absenteeism cost. The per person annual costs estimated using a regression approach were approximately twice as much as the costs using the sum disease-specific approach, suggesting a potential role for 'spillover' costs among working adults with ADHD. Prescription drug costs were top-ranked contributors to the direct medical costs. As a group, working adults with ADHD are relatively understudied and more research is needed to better understand the burden of ADHD in this group.