Inattention Six or more of the following symptoms in children, and five or more in adults, excluding situations where these symptoms are better explained by another psychiatric or medical condition:
  • Frequently overlooks details or makes careless mistakes
  • Often has difficulty maintaining focus on one task or play activity
  • Often appears not to be listening when spoken to, including when there is no obvious distraction
  • Frequently does not finish following instructions, failing to complete tasks
  • Often struggles to organise tasks and activities, to meet deadlines, and to keep belongings in order
  • Is frequently reluctant to engage in tasks which require sustained attention
  • Frequently loses items required for tasks and activities
  • Is frequently easily distracted by extraneous stimuli, including thoughts in adults and older teenagers
  • Often forgets daily activities, or is forgetful while completing them.
 Multiple symptoms of inattention that directly negatively impact occupational, academic or social functioning. Symptoms may not be present when engaged in highly stimulating tasks with frequent rewards. Symptoms are generally from the following clusters:
  • Struggles to maintain focus on tasks that aren't highly stimulating/rewarding or that require continuous effort; details are often missed, and careless mistakes are frequent in school and work tasks; tasks are often abandoned before they are completed.
  • Easily distracted (including by own thoughts); may not listen when spoken to; frequently appears to be lost in thought
  • Often loses things; is forgetful and disorganised in daily activities.

The individual may also meet the criteria for hyperactivity-impulsivity, but the ina
Hyperactivity-Impulsivity Six or more of the following symptoms in children, and five or more in adults, excluding situations where these symptoms are better explained by another psychiatric or medical condition:
  • Is often fidgeting or squirming in seat
  • Frequently has trouble sitting still during dinner, class, in meetings, etc.
  • Frequently runs around or climbs in inappropriate situations. In adults and teenagers, this may be present only as restlessness.
  • Often cannot quietly engage in leisure activities or play
  • Frequently seems to be "on the go" or appears uncomfortable when not in motion
  • Often talks excessively
  • Often answers a question before it is finished, or finishes people's sentences
  • Often struggles to wait their turn, including waiting in lines
  • Frequently interrupts or intrudes, including into others' conversations or activities, or by using people's things without asking.
 Multiple symptoms of hyperactivity/impulsivity that directly negatively impact occupational, academic or social functioning. Typically, these tend to be most apparent in environments with structure or which require self-control. Symptoms are generally from the following clusters:
  • Excessive motor activity; struggles to sit still, often leaving their seat; prefers to run about; in younger children, will fidget when attempting to sit still; in adolescents and adults, a sense of physical restlessness or discomfort with being quiet and still.
  • Talks too much; struggles to quietly engage in activities.
  • Blurts out answers or comments; struggles to wait their turn in conversation, games, or activities; will interrupt or intrude on conversations or games.
  • A lack of forethought or consideration of consequences when making decisions or taking action, instead tending to act immediately (e.g., physically dangerous behaviours including reckless driving; impulsive decisions).

The individual may also meet the criteria for inattention, but the hyperactive-impulsive symptoms are predominant.
Combined Meet the criteria for both inattentive and hyperactive-impulsive ADHD. Criteria are met for both inattentive and hyperactive-impulsive ADHD, with neither clearly predominating.