DSM-5 Criteria for ADHD 

1. Inattention: Six or more symptoms of inattention for children up to age 16, or five or more for adolescents 17 and older and adults; symptoms of inattention have been present for at least 6 months, and they are inappropriate for developmental level:
   • Often fails to give close attention to details or makes careless mistakes in schoolwork, at work, or with other activities.
   • Often has trouble holding attention on tasks or play activities.
   • Often does not seem to listen when spoken to directly.
   • Often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace (e.g., loses focus, side-tracked).
   • Often has trouble organizing tasks and activities.
   • Often avoids, dislikes, or is reluctant to do tasks that require mental effort over a long period of time (such as schoolwork or homework).
   • Often loses things necessary for tasks and activities (e.g. school materials, pencils, books, tools, wallets, keys, paperwork, eyeglasses, mobile telephones).
   • Is often easily distracted
   • Is often forgetful in daily activities.
2. Hyperactivity and Impulsivity: Six or more symptoms of hyperactivity-impulsivity for children up to age 16, or five or more for adolescents 17 and older and adults; symptoms of hyperactivity-impulsivity have been present for at least 6 months to an extent that is disruptive and inappropriate for the person’s developmental level:
   • Often fidgets with or taps hands or feet, or squirms in seat.
   • Often leaves seat in situations when remaining seated is expected.
   • Often runs about or climbs in situations where it is not appropriate (adolescents or adults may be limited to feeling restless).
   • Often unable to play or take part in leisure activities quietly.
   • Is often "on the go" acting as if "driven by a motor".
   • Often talks excessively.
   • Often blurts out an answer before a question has been completed.
   • Often has trouble waiting his/her turn.
   • Often interrupts or intrudes on others (e.g., butts into conversations or games)

• Several inattentive or hyperactive-impulsive symptoms were present before age 12 years.
• Several symptoms are present in two or more setting, (e.g., at home, school or work; with friends or relatives; in other activities).
• There is clear evidence that the symptoms interfere with, or reduce the quality of, social, school, or work functioning.
• The symptoms do not happen only during the course of schizophrenia or another psychotic disorder. The symptoms are not better explained by another mental disorder (e.g. Mood Disorder, Anxiety Disorder, Dissociative Disorder, or a Personality Disorder).

Reference