The level of aggression being studied is equivalent to that in moderate to severe Oppositional Defiant Disorder with the severity due to the tantrums rather than passive aggression (Modified Overt Aggression Score between 15-50). For 20 years a blood pressure medication, guanfacine (Tenex), has also been used for impulse control (e.g. in Attention Deficit Disorder, in Tourette's Syndrome) and to calm the sympathetic nervous system when it is hyper-aroused (e.g. in opiate and nicotine withdrawal]. Both impulsivity and hyper arousal can also promote intermittent explosive aggression. If guanfacine treats impulsivity and hyper arousal, it is logical to ask if guanfacine can treat intermittent explosive aggression.