We studied 83 children between the ages of 12 and 16 who had been diagnosed as having the hyperactive syndrome 2 to 5 years earlier. About half of the children were markedly improved, one-quarter remained unchanged, and the remaining quarter lay in between. The symptoms of restlessness, distractibility, impulsiveness, excitability, and aggressiveness seemed to persist in most of the children, and were associated with poor performance in school and low self-esteem. A number of the children were involved in delinquent behavior.