Reward-Based Biotypes in ADHD

Investigators have theorized ADHD symptoms can arise in patients who have demonstrably different types of neurobiological dysfunction. This redirects a longstanding search for common disorder pathophysiology to efforts seeking to identify ADHD “biotypes.” Successful prior examples of this approach have examined cognitive tests reliably linked to the ADHD diagnosis itself but are inconsistently expressed in individual patients. Although reward dysfunction is strongly implicated in ADHD, it is not yet known if patients can be biotyped into subgroups with distinct reward function and reinforcement learning characteristics.