To the Editor: Dr Volkow and colleagues1 studied the biological basis of attention-deficit/hyperactivity disorder (ADHD), using positron emission tomography (PET) to assess dopamine transporters and D2/D3 receptors. This was a study of adult ADHD, which can be overdiagnosed because of symptom overlap with mood and anxiety disorders, and I am concerned that the methods used in this study to evaluate the participants for true ADHD may have been inadequate.
Zametkin AJ. Dopamine Reward Pathway in Adult ADHD. JAMA. 2010;303(3):232-234. doi:10.1001/jama.2009.1998