ADHD
Attention Deficit Hyperactivity Disorder (ADHD) is a brain disorder marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development.

Inattention
People with symptoms of inattention may often:
- 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 or 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
Hyperactivity-Impulsivity
People with symptoms of hyperactivity-impulsivity may often:
- 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”
- Talk nonstop
- 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

Diagnosis of ADHD requires a comprehensive evaluation by a licensed clinician, such as a psychologist or psychiatrist with expertise in ADHD. For a person to receive a diagnosis of ADHD, the symptoms of inattention and/or hyperactivity-impulsivity must be chronic or 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 a 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 of ADHD can be mistaken for emotional or disciplinary problems or missed entirely in quiet, well-behaved children, leading to a delay in diagnosis. Adults with undiagnosed ADHD may have a history of poor academic performance, problems at work, or difficult or failed relationships.