Are hypnosis and dissociation related? New evidence for a connection

Inducing dissociative states: A (re)view from the laboratory

Laboratory-based inductions of dissociative states promise to facilitate understanding of the etiology, maintenance, and treatment of dissociation and dissociative disorders. In the present scoping review, we identified articles via a systematic search of PsycINFO, PsycARTICLES, PubMed, and Google Scholar, resulting in 59 articles that met a priori inclusion criteria. Of the 19 techniques described, numerous elicited changes in dissociative symptoms. However, studies were highly heterogeneous regarding their definition and measurement of dissociation. We call attention to relevant validity concerns presented by laboratory-based inductions and offer directions and recommendations for future research.

Assessing malingering and personality styles in dissociative identity disorder: a case study

Dissociative Identity Disorder (DID), formerly Multiple Personality Disorder, involves two or more distinct identities controlling behaviour, stemming from trauma-related dissociation. Understanding DID's cognitive, neural, and psychometric aspects remains a challenge, especially in distinguishing genuine cases from malingering. We present a case of a DID patient with nine identities, evaluated to rule out malingering. Using the Millon Index of Personality Styles, we assessed the primary and two alternate identities, revealing marked differences. High consistency scores support validity. We suggest employing personality inventories beyond symptomatology to characterise dissociative identities' consistency and adaptation styles, aiding in malingering assessments in future studies.

Beyond imagination: Hypnotic visual hallucination induces greater lateralised brain activity than visual mental imagery

Hypnotic suggestions can produce a broad range of perceptual experiences, including hallucinations. Visual hypnotic hallucinations differ in many ways from regular mental images. For example, they are usually experienced as automatic, vivid, and real images, typically compromising the sense of reality. While both hypnotic hallucination and mental imagery are believed to mainly rely on the activation of the visual cortex via top-down mechanisms, it is unknown how they differ in the neural processes they engage. Here we used an adaptation paradigm to test and compare top-down processing between hypnotic hallucination, mental imagery, and visual perception in very highly hypnotisable individuals whose ability to hallucinate was assessed. By measuring the N170/VPP event-related complex and using multivariate decoding analysis, we found that hypnotic hallucination of faces involves greater top-down activation of sensory processing through lateralised neural mechanisms in the right hemisphere compared to mental imagery. Our findings suggest that the neural signatures that distinguish hypnotically hallucinated faces from imagined faces lie in the right brain hemisphere.

Making EGMs Accountable: Can an Informative and Dynamic Interface Help Players Self-regulate?

Electronic gaming machines (EGMs) are recognised as one of the most harmful gambling forms, because they promote high-speed repetitive gambling and automatically reinvest winnings. These features, amongst others, make it difficult for EGM gamblers to keep track of their play. Tools to assist gamblers exist, but have limited effectiveness because they require user registration and manual activation, leading to low uptake. The present study aimed to evaluate the effect of a more informative interface (including removal of automatic reinvestment of winnings) and pop-up messages on gambling behaviour, and on player experience. A total of 213 Australian participants, recruited through social media, played a simulated online EGM. The experiment was a two (standard vs. informative interface) × two (pop-ups absent vs. present) between-subjects design. The informative interface: promoted keeping track of spins played; increased accurate estimation of amount spent (as did pop-up messages) and time played; and provided game usage figures which acted as cues to quit play. Once the initial deposit (but not winnings) was expended, informative interface users could opt to reinvest their winnings, although many opted to exit at that point. No difference in total spending or dissociation was observed between experimental groups. Informative interface users reported no reduction in enjoyment. Pop-up messages reduced enjoyment with the standard interface, but increased enjoyment when paired with an informative interface. These findings indicate that a more informative interface and pop-up messages may be useful in reducing the harmful nature of EGMs.

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.

Applicability of hypnosis to the treatment of Complex PTSD and dissociation

In considering the applicability of hypnosis to treating Complex PTSD (C-PTSD) we examine the relationship between trauma, hypnosis, and dissociation, the latter being a common response to traumatization that is particularly salient in C-PTSD. We then provide an overview of the nature of C-PTSD, which research is beginning to demonstrate is considerably more prevalent than the more circumscribed PTSD syndrome depicted in the DSM. Building on this foundation, we discuss the reasons why hypnotically structured treatment is particularly well suited for C-PTSD, explaining how each of the major aspects of this syndrome can be addressed within a hypnotic framework.

Characteristics of Adolescents Affected by Mass Psychogenic Illness Outbreaks in Schools in Nepal: A Case-Control Study

This paper presents the first systematic case-control study of correlates of mass psychogenic illness (MPI) in an adolescent school population. MPI is generally construed as a dissociative phenomenon spread by social contagion to individuals who are prone to dissociation. We sought to test if the correlates of dissociative experiences most commonly proposed in the literature could predict caseness among students affected by episodes of mass psychogenic illness occurring in schools in Nepal. We assessed 194 cases and 190 controls (N = 384) of ages 11-18 years from 12 public schools. Cases and controls were comparable on all demographic variables, except for family configuration, with nuclear families more common among those affected. In bivariate comparisons, caseness was associated with childhood physical neglect and abuse, as well as living in nuclear families, peritraumatic dissociation, dissociative tendencies, and depressive and post-traumatic stress symptoms. Hypnotizability emerged as the strongest correlate of psychogenic illness among the cognitive and personality trait variables. However, in multivariable logistic regression, the correlates of dissociation did not predict caseness, suggesting that they do not adequately account for the phenomenon of mass psychogenic illness. An ad-hoc Classification and Regression Trees analysis showed that if an adolescent was highly hypnotizable and reported high rates of peritraumatic dissociative experiences, then there was a 73% probability of being a case in a mass psychogenic illness episode. Future studies involving other psychological, social and cultural factors, as well as school- and family-related factors are needed to understand the correlates of mass psychogenic illness and guide prevention and intervention.

Factor structure and reliability of the Spanish version of the Dissociative Ability Scale

Everybody has dissociative ability to some extent, though this may vary from one individual to another. Several tests have been designed to measure dissociative ability, such as the Dissociative Ability Scale (Fisher, Johnson, & Elkins, 2013). Thus, the aim of this study was to assess the reliability and validity of the Spanish version of this test in a sample of 204 undergraduates seeking a fine arts degree at the University of Vigo (Spain). The reliability and validity of the Dissociative Ability Scale was found to be satisfactory for measuring dissociative ability. The results are discussed and innovative lines of research are proposed.

Patterns of hypnotic response, revisited

It has long been speculated that there are discrete patterns of responsiveness to hypnotic suggestions, perhaps paralleling the factor structure of hypnotizability. An earlier study by Brenneman and Kihlstrom (1986), employing cluster analysis, found evidence for 12 such profiles. A new study by Terhune (2015), employing latent profile analysis, found evidence for three such patterns among highly hypnotizable subjects, and a fourth comprising subjects of medium hypnotizability. Some differences between the two studies are described. Convincing identification of discrete "types" of high hypnotizability, such as dissociative and nondissociative, may require a larger dataset than is currently available, but also data pertaining directly to divisions in conscious awareness and experienced involuntariness.