Since 1998, millions of parents and adults have trusted ADDitude's expert guidance and support for living better with ADHD and its related mental health conditions. Attention deficit hyperactivity disorder (ADHD) [1] is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple contexts, and developmentally inappropriate. [8] ADHD symptoms arise from executive dysfunction. [17] Children and Adults with Attention-Deficit/Hyperactivity Disorder (CHADD) is the nation's leading nonprofit organization serving people affected by ADHD. ADHD, or Attention Deficit Hyperactivity Disorder, is a neurodevelopmental disorder that affects both children and adults. It is characterized by signs such as difficulty with focus, hyperactivity, and impulsivity. Read about ADHD, its types, symptoms, possible risk factors, screening, treatment, and CDC's work. What is ADHD? Attention deficit hyperactivity disorder (ADHD), usually first diagnosed in childhood, can appear in a variety of forms and has many possible causes. NIMH researches attention-deficit/hyperactivity disorder (ADHD). Find resources on the signs and symptoms of ADHD and potential treatments and therapies. ADHD is the most commonly diagnosed mental disorder in children. Find out the symptoms in children and adults, types, causes, diagnosis, treatment, and outlook. ADHD (attention-deficit/hyperactivity disorder) is a type of brain difference that can make it hard to pay attention, finish tasks and sit still. Treatment can help. Attention-deficit/hyperactivity disorder, also called ADHD, is a long-term condition that affects millions of children. It often continues into adulthood. ADHD includes a mix of ongoing problems. These can include having a hard time paying attention, being hyperactive and being impulsive.