Attention deficit hyperactivity disorder (ADHD) is the most commonly studied and diagnosed psychiatric disorder in children and adolescents. ADHD is characterized by inattentiveness, hyperactivity or restlessness, disruptive behavior, and poor impulse control. Children with ADHD have an inability to focus and are easily distracted. They also tend to be very physically active and have trouble sitting still. Without treatment, ADHD can affect a child's social development and school performance. With treatment, most children with ADHD improve. Seeing a mental health professional can provide children with ADHD critical help in handling frustrations and building self-esteem. Parents of children suffering from ADHD can also benefit from therapy to help them develop healthy and supportive ways of coping.