We report a case study of an 18-year-old female who presented with symptoms associated with several discrete diagnostic syndromes: obsessive-compulsive disorder, trichotillomania, major depression, and anorexia nervosa. Improvement in each occurred after treatment with the serotonin selective reuptake inhibitor, fluoxetine, suggesting that such syndromes share a common serotonin neurotransmitter disturbance. Furthermore, the combined effects of medication and psychotherapy resulted in improvement in assertiveness, sense of security, self-worth, flexibility, and self-regulation. We discuss the pharmacological and psychotherapeutic implications of possible psychophysiologic similarities among the previously mentioned syndromes. (C) 1995 by John Wiley & Sons, Inc.