Impulsivity can be broadly defined as actions that are poorly conceived, prematurely expressed, unduly risky, or inappropriate to a situation and that often result in undesirable outcomes [6]. With regard to aggression, impulsivity is related to an emotionally charged uncontrolled type of aggressive display rather than planned, unemotional behaviour [7]. Impulsive aggression is common among ADHD youth. It is unpremeditated, resulting in serious damage to either people or property and is grossly out of proportion to any real or perceived provocation [8] [9]. Impulsive aggression may also contain both motor (failure to inhibit behaviour resulting in fast inaccurate responses) and cognitive (distorted judgement of possible outcomes) components [10].