Attention-Deficit Hyperactivity Disorder (ADHD), is a neurobehavioural developmental disorder affecting about 3-5% of the world's population under the age of 19 . It typically presents itself during childhood, and is characterized by a persistent pattern of inattention and/or hyperactivity, as well as forgetfulness, poor impulse control or impulsivity, and distractibility. Diagnostic and Statistical Manual of [American Psychiatric Association, 2000. ADHD is currently considered to be a persistent and chronic condition for which no medical cure is available. ADHD is most commonly diagnosed in children and, over the past decade, has been increasingly diagnosed in adults. About 60% of children diagnosed with ADHD retain the condition as adults. It appears to be highly heritable, although one-fifth of all cases are estimated to be caused from trauma or toxic exposure. Methods of treatment usually involve some combination of medications, behaviour modifications, life style changes, and counseling.

The scientific consensus in the field, and the consensus of the national health institutes of the world, is that ADHD is a disorder which impairs functioning, and that many adverse life outcomes are associated with ADHD. It has been frequently said by a minority of news sources, social critics, certain religions, and individual medical professionals, to be a controversial disorder. These critics question its classification as a single syndrome, its causes, its treatment, and even the existence of ADHD. See Controversy about ADHD.