Attention deficit hyperactivity disorder (ADHD) begins in childhood and may continue into adulthood, affecting an individual's activities professionally, socially, and within their family. ADHD is characterized by symptoms of inattention, hyperactivity, and impulsiveness. While it is a widely recognized disorder, some professionals still question its validity. ADHD has been linked to changes in the brain regions involved in behavioral inhibition, attention, and neurotransmitter systems. Treatment may include therapy, support at home and school, and stimulant medications which help the functioning of affected brain areas without causing addiction.