Attention deficit hyperactivity disorder (ADHD) persists into adulthood in approximately 10 to 60 percent of individuals diagnosed in childhood. Expression of symptoms changes in the adult assessed for the disorder. The symptoms of adult ADHD resemble the symptoms of childhood ADHD, but symptom intensity, especially hyperactivity, may decrease over time. A childhood history of ADHD is requisite for a diagnosis of adult ADHD, although full DSM-IV criteria for the childhood disorder need not be met as long as there exists impairment in multiple settings (i.e., academic, relationship, and occupational). There is a high probability of co-morbid disorders, as well as the likelihood that the adult with ADHD has developed coping mechanisms to compensate for his or her impairment. Pharmacologic treatments and multiple types of psychotherapy are available for adults with ADHD.