ABSTRACT
The cardinal features of attention deficit hyperactivity disorder (ADHD) are extreme and persistent restlessness, sustained and prolonged motor overactivity, and difficulty in maintaining attention. These behaviours begin in childhood and are relatively chronic. They are not explained by gross neurological, sensory, language or motor impairment or by learning disabilities or severe emotional disturbance. These difficulties are typically associated with deficits in rule-governed behaviour or in maintaining a consistent pattern of work performance over time. Rule-governed behaviour refers to the capacity for language such as commands, directions, instructions or descriptions to direct an individual’s course of action.
