[Symptoms and Pathogenesis of ADHD].

Diagnosis of ADHD in adulthood is increasing rapidly in Japan. The ADHD symptoms occur on a continuum with those of normal development and are likely to fluctuate with the growth process and environment at the time of diagnosis. Especially in adult cases, comorbid psychiatric disorders tend to influence the characteristics of ADHD. ADHD has diverse clinical manifestations and a heterogeneous biological background. In addition to the RDoC approach to elucidate the pathogenesis and etiology of the disorder, we expect that attempts will be made to classify the disorder into relatively homogeneous biological subcategories.