BACKGROUNDThe attention deficit hyperactivity disorders (ADHD) have long been recognized in children. During the past several years, there is growing evidence that these disorders persist into adulthood. Many adult patients seek treatment for these problems from neurologists.REVIEW SUMMARYThis article reviews the historical evidence for ADHD, plus recent studies that support the contention that the disorder persists into adulthood. Critical articles are reviewed. The concept of coexistent conditions (disorders that are concurrent with ADHD in the same patient) is explained. A clinical approach is described, and effective treatment modalities are discussed.CONCLUSIONADHD is a complicated disorder that persists into adulthood. ADHD can be part of a spectrum of disorders that affect adults. The clinician can make the diagnosis during a standard office visit using an interview technique. Medical and behavioral therapies can produce gratifying results.