People with ADHD show a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development:

​

Inattention:

​

Six or more symptoms of inattention for children up to age 16 years, or five or more for adolescents age 17 years 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.

​

​

Hyperactivity and Impulsivity:

​

Six or more symptoms of hyperactivity-impulsivity for children up to age 16 years, or five or more for adolescents age 17 years 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 their turn.

• Often interrupts or intrudes on others (e.g., butts into conversations or games)

​

​

In addition, the following conditions must be met:

​

• Several inattentive or hyperactive-impulsive symptoms were present before age 12 years.

• Several symptoms are present in two or more settings, (such as 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 are not better explained by another mental disorder (such as a mood disorder, anxiety disorder, dissociative disorder, or a personality disorder). The symptoms do not happen only during the course of schizophrenia or another psychotic disorder.

​

​

Based on the types of symptoms, three kinds (presentations) of ADHD can occur:

​

• Predominantly Inattentive Presentation: if enough symptoms of inattention, but not hyperactivity-impulsivity, were present for the past six months

• Predominantly Hyperactive-Impulsive Presentation: if enough symptoms of hyperactivity-impulsivity, but not inattention, were present for the past six months.

• Combined Presentation: if enough symptoms of both criteria inattention and hyperactivity-impulsivity were present for the past 6 months

​

Because symptoms can change over time, the presentation may change over time as well.