This paper reviews the research on dissociation and the development of psychopathology in children and adolescents. Definitions and dimensions of dissociation are addressed, noting its range from normative daydreaming to the extremes found in individuals with multiple personality disorder. Memory dysfunctions, disturbances of identity, passive influence experiences, auditory hallucinations, and spontaneous trance states are among the manifestations of dissociative disorders. Measurement of dissociation may involve use of a self-report scale called the "Dissociative Experiences Scale," structured psychiatric interviews, and other psychological tests. Diagnosis is, however, very difficult especially in children and adolescents. Research with dissociation scales and structured interviews has found close linkage of high levels of dissociation with traumatic experiences. Research on the influence of dissociation on symptoms and behavior problems in traumatized and nontraumatized child samples has found that dissociation is diffusely related to psychopathology. Research findings also suggest that the frequency of dissociation normally declines over the life span. Research on the impact of dissociation on developmental processes has examined dissociative alterations in the development of self, dissociative disruptions of self-agency, dissociative disturbances of self-coherence, disturbances of self-affectivity, and dissociative interruptions in self-continuity. (Contains 60 references.) (DB)