The varied relationship between hypnosis and dissociative phenomena: Implications for traumatology.

Although metanalytic evidence exists to support the long-term efficacy of hypnotic interventions in the treatment of trauma, assertions that hypnosis may induce trauma or exacerbate existing posttraumatic reactions through activating dissociative processes seem to persist in some circles. While multiple studies have established that hypnotic induction produces dissociative phenomena, what has not yet been clearly explicated is the degree to which varieties of dissociative phenomena differentially elicited by hypnotic induction tend to skew toward the pathological or nonpathological end of the continuum of dissociation. The authors of the current study explore the connection between hypnotic susceptibility and facets of dissociation, employing the Harvard Group Scale of Hypnotic Susceptibility: A (HGSHS:A) and the State Scale of Dissociation (SSD). A significantly greater change in state dissociation was observed in their hypnosis condition as compared with a novel control condition (t (82) = 3.235, p =.002, d =.70), confirming that a relationship appears to exist between hypnosis and dissociation. A discussion of the differential effect of hypnosis on SSD subscales follows, specifically indicating less activation of the more putatively pathological facets, namely identity confusion and identity alteration. This finding may serve to assuage some concerns around the potential for iatrogenesis in working with traumatized patients.

Are hypnosis and dissociation related? New evidence for a connection.

The authors revisit the question of the existence of a relationship between hypnotizability and dissociative capacity. In the present study, the State Scale of Dissociation (SSD) replaced the commonly employed Dissociative Experiences Scale (DES) as a measure of dissociation, due to the latter capturing primarily pathological aspects of dissociation. Relationships between the Harvard Scale of Hypnotic Susceptibility, Form A (HGSHS:A), the SSD, and the Phenomenology of Consciousness Inventory (PCI) were assessed in the context of hypnosis. Robust results were found when comparing pre- to post-SSD scores, suggesting heightened nonpathological forms of dissociation are indeed related to hypnotizability. The appropriateness of the DES and similar trait-based measures for evaluating hypnotic phenomena is discussed as well as the relationships between PCI and SSD subscales.