Attention-Deficit/Hyperactivity Disorder is characterized by hyperactive behaviors that are extreme for a particular developmental period, persistent across different impairment situations, and linking to significant impairments in functioning. There may be particularly difficulty controlling their activity in situations that call for sitting still such as classrooms. They may also experience difficulty getting along with peers caused. By aggressive and intrusive behaviors, difficulty noticing subtle social cues, and being singled out very quickly and rejected or neglected by peers. The symptoms are ADHD present before age 12 and present in two or more setting such as at home, school, or work. ADHD may cause significant impairment in social, academic, or occupational functioning and may be frequently rejected by peers. For children 6 symptoms of inattention and/or hyperactivity-impulsivity are required, but only 5 for ages 17 and above. Three specifiers to indicate which symptoms predominate or predominately inattentive presentation, predominantly hyperactive-impulsive presentation, and combined presentation which is seen in most children. ADHD often occurs with conduct disorder where ADHD is associated more with off-task behavior in school, cognitive and achievement deficits, and better long-term prognosis. It also co-occurs with anxiety and depression where there is a 30% likelihood of having a comorbid internalizing disorder, learning disorders, and substance use disorders. Prevalence estimates 8 to 11% and has risen dramatically in the past decade. Public policy can affect diagnosis rates through access to comprehensive diagnostic testing and education policies. ADHD is 3 times more common in boys than girls which may be because boys’ behavior is more likely to be aggressive. Symptoms are persistent beyond childhood with 60-74% still exhibiting symptoms into at least early adulthood. By early adulthood, young women who continued to meet diagnostic criteria for ADHD were more likely to have internalizing and externalizing psychopathology and more likely to have unplanned pregnancies, lower academic achievement, and greater substance use due to risky decisions.