Abstract
The mechanisms driving disparities in mental health care are not well understood. This paper develops a structural model of diagnosis for attention deficit hyperactivity disorder (ADHD), highlighting how patient and physician factors can result in disparities. Using electronic health record data, I estimate model parameters and decompose the observed male∶female ADHD diagnostic difference of 2.3∶1. Simulations show that only 20%–25% of this diagnostic difference can be explained by underlying symptom prevalence, with the majority driven by differences in diagnostic thresholds. I find that physicians view missed diagnosis to be costlier for their male patients, which I argue may have economic justifications.