Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder, often diagnosed in childhood or adolescence, that causes problems in sustaining attention, concentration, and memory and in some cases, causes hyperactivity and impulsivity. The disorder is typically identified when a child is in school and is required to remain seated, pay attention to teachers, complete schoolwork, and follow rules. Children with ADHD often struggle in one or more of these areas due to the symptoms of the disorder. Although ADHD is a disorder diagnosed in childhood, adults can also struggle with ADHD. However, in order to meet criteria for the diagnosis, symptoms must have been present before age 12.