Diagnosis of ADHD requires a comprehensive evaluation by a licensed clinician, such as a pediatrician, psychologist, or psychiatrist with expertise in ADHD. The symptoms of inattention and/or hyperactivity/impulsivity must be chronic and long-lasting, impair the person's functioning, and cause the person to fall behind normal development for his or her age. Most children with ADHD receive diagnosis during the elementary school years. For an adolescent or adult to receive a diagnosis of ADHD, the symptoms need to have been present prior to age 12.
ADHD symptoms can appear as early as between the ages of 3 and 6 and can continue through adolescence and adulthood. Symptoms can be mistaken for emotional or disciplinary problems or missed entirely in quiet, well-behaved children, leading to a delay in diagnosis.
Inattention and hyperactivity/impulsivity are the key behaviors of ADHD. Some people with ADHD only have problems with one of the behaviors while others have both. Most children have the combined type of ADHD. In preschool, the most common ADHD symptom is hyperactivity. While it is normal to have some inattention, unfocused motor activity and impulsivity, for people with ADHD these behaviors are more severe, occur more often, and interfere with or reduce the quality of how they function socially, at school, or in a job.
Overlook or miss details, make careless mistakes in schoolwork, at work, or during other activities
Have problems sustaining attention in tasks or play, including conversations, lectures, or lengthy reading
Not seem to listen when spoken to directly
Not follow through on instructions and fail to finish schoolwork, chores, or duties in the workplace or start tasks but quickly lose focus and get easily sidetracked
Have problems organizing tasks and activities, such as what to do in sequence, keeping materials and belongings in order, having messy work and poor time management, and failing to meet deadlines
Avoid or dislike tasks that require sustained mental effort, such as schoolwork or homework, or for teens and older adults, preparing reports, completing forms or reviewing lengthy papers
Lose things necessary for tasks for activities, such as school supplies, pencils, books, tools, wallets, keys, paperwork, eyeglasses, and cell phones
Be easily distracted by unrelated thoughts or stimuli
Be forgetful in daily activities, such as chores, errands, returning calls, and keeping appointments
Fidget and squirm in their seats
Leave their seats in situations when staying seated is expected, such as in the classroom or in the office
Run or dash around or climb in situations where it is inappropriate or, in teens and adults, often feel restless
Be unable to play or engage in hobbies quietly
Be constantly in motion or "on the go", or act as if "driven by a motor"
Blurt out an answer before a question has been completed, finish other people's sentences, or speak without waiting for a turn in conversation
Have trouble waiting his or her turn
Interrupt or intrude on others, for example in conversations, games, or activities