Pediatric patients with neurotic and hyperkinetic reaction patterns have been treated experimentally on one of 3 schedules: (a) brief psychotherapy, (b) brief psychotherapy plus placebo, (c) brief psychotherapy plus perphenazine. Analysis of the clinical response rates has led us to the following conclusions:1. Children with neurotic symptomatology show a prompt and enduring response to a brief program of psychotherapy at a level of improvement (60-70%) that is significantly greater than that attained by children with hyperkinetic syndromes (15-40%).2. No evidence was obtained for any enhancement of the response to brief psychotherapy from the addition of placebo medication.3. We were unable to demonstrate a significant difference between response to placebo and to perphenazine when administered concomitantly with psychotherapy.The implications of these findings have been discussed.