It is the most common neurobehavioral disorder of childhood with symptoms of hyperactivity, impulsivity,?and/or?inattention. It often persists in adulthood5

Population surveys suggest that ADHD occurs in most cultures in about 5% of children and about 2.5% of adults.


ADHD is a syndrome with core symptoms of hyperactivity, impulsivity?and inattention.

For each core symptom, six (or more) of the mentioned symptoms have persisted for at least 6 months to a degree that is inconsistent with developmental level, be present before the age of 12 years and that result in impairment of activities in two or more settings (e.g., at home, school, or work; with friends or relatives; in other activities).

Symptoms of hyperactivity and impulsivity may include:

  • Excessive fidgetiness (eg, tapping the hands or feet, squirming in seat)
  • Difficulty remaining seated when sitting is required (eg, at school, work, etc)
  • Restlessness (in adolescents) or inappropriate running around or climbing in younger children
  • Difficulty playing quietly
  • Difficult to keep up with, seeming to always be “on the go”
  • Excessive talking
  • Difficulty waiting turns
  • Blurting out answers too quickly
  • Interruption or intrusion of others


Symptoms of inattention may include:

  • Failure to provide close attention to detail, careless mistakes
  • Difficulty maintaining attention in play, school, or home activities
  • Seems not to listen, even when directly addressed
  • Fails to follow through (eg, homework, chores, etc)
  • Difficulty organizing tasks, activities, and belongings
  • Avoids tasks that require consistent mental effort
  • Loses objects required for tasks or activities (eg, school books, sports equipment, etc)
  • Easily distracted by irrelevant stimuli
  • Forgetfulness in routine activities (eg, homework, chores, etc)


Genetics: there?s a familial tendency.

Environmental risk factors: Prenatal cannabis and nicotine exposure, pre and perinatal obstetric complications and very low birth weight (<1500 gms), exposure to lead and other toxins.


Depending upon the predominant symptoms, ADHD can be categorized into one of the three subtypes listed below:

  • Predominantly inattentive
  • Predominantly hyperactive-impulsive
  • Combined


  • Parent training and education programmes
  • Cognitive therapy
  • Pharmacotherapy: includes psychostimulants (methylfenidate, dexamfetamine) and nonstimulants (atomoxetine)



  1. Oxford handbook of clinical specialties 9th ed.
  2. Oxford handbook of pediatrics 2nd ed.
  3. Uptodate
  4. American Psychiatric Association. Attention-deficit/hyperactivity disorder. In: Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, American Psychiatric Association, Arlington,
  5. Fayyad J, De Graaf R, Kessler R, et al. Cross-national prevalence and correlates of adult attention-deficit hyperactivity disorder. Br J Psychiatry 2007; 190:402