May 9, - Adult attention deficit/hyperactivity disorder (ADHD) is far more common that previously thought, according to a recent study published in the journal JAMA Psychiatry — though it's often undiagnosed. There's been a recent rise in the number of adults diagnosed with ADHD, which was previously considered extremely rare. Jump to What can a psychiatrist do for ADHD? - Psychiatrists are the best-placed specialists to diagnose and treat adults with ADHD. devise a management plan for ADHD. diagnose and treat any other mental health issues, including depression or alcohol and drug use. prescribe medication.Signs and symptoms of · Diagnosis of ADHD · How is ADHD managed?