That's Attention Defecit Hyperactivity Disorder (ADHA) as described by Christopher Green, a psychiatrist and author of Driven to Distraction, a seminal book on the condition.

According to epidemiological data, approximately 6 per cent of people have ADHD or ADD - Attention Deficit Disorder without hyperactivity. ADHD and ADD are basically the same thing. The three main symptoms are: distractibility (poor sustained attention to tasks); impulsiveness (impaired impulse control and delay of gratification); and hyperactivity (excessive activity and physical restlessness).

In order to meet diagnostic criteria these behaviours must be excessive, long-term, and pervasive. The behaviours must appear before age seven, and continue for at least six months.

A crucial consideration is that the behaviours must create a real handicap in at least two areas of a person's life, such as school, home, work, or social settings. These criteria set ADHD apart from the "normal" distractibility and impulsive behaviour of childhood, or the effects of the hectic and over-stressed lifestyle prevalent in our society.

A child with ADHD often fails to give close attention to details or makes careless mistakes; often has difficulty sustaining attention given to tasks; often does not seem to listen when spoken to directly; often fails to follow instructions carefully and completely; loses or forgets important things; feels restless, fidgets or squirms, runs, climbs or talks excessively; often blurts out answers before hearing the whole question and often has difficulty waiting his or her turn.

The exact nature and severity of ADHD symptoms varies from person to person, however.