Each patient with Attention Deficit Disorder (ADD), with or without hyperactivity, is unique in the variety and severity of the handicapping conditions associated with ADD. The use of a well- designed teacher rating scale can provide the clinician with a behavioral prafile of each patient. The importance of knowing the child's specific problems is emphasized by the results of this research, which show that methylphenidate has a major effect in improving attention, is helpful in decreasing activity level, but often has only a minor effect on deficient social skills and oppositional (aggressive) behavior.