The response set theory of hypnosis reconsidered: toward an integrative model

How hypnotic suggestions work - A systematic review of prominent theories of hypnosis

In recent decades, hypnosis has increasingly moved into the mainstream of scientific inquiry. Hypnotic suggestions are frequently implemented in behavioral, neurocognitive, and clinical investigations and interventions. Despite abundant reports about the effectiveness of suggestions in altering behavior, perception, cognition, and agency, no consensus exists regarding the mechanisms driving these changes. This article reviews competing theoretical accounts that address the genesis of subjective, behavioral, and neurophysiological responses to hypnotic suggestions. We systematically analyze the broad landscape of hypnosis theories that best represent our estimation of the current status and future avenues of scientific thinking. We start with procedural descriptions of hypnosis, suggestions, and hypnotizability, followed by a comparative analysis of systematically selected theories. Considering that prominent theoretical perspectives emphasize different aspects of hypnosis, our review reveals that each perspective possesses salient strengths, limitations, and heuristic values. We highlight the necessity of revisiting extant theories and formulating novel evidence-based accounts of hypnosis.

Cognitive Behavioral Therapy and Hypnosis in the Treatment of Major Depressive Disorder: A Randomized Control Trial

We investigated whether adding hypnosis to CBT (CBTH) improved treatment outcomes for MDD with a two-armed, parallel-treated, randomized-controlled trial using anonymous self-report and clinician-blinded assessments. Expectancy, credibility, and attitude to hypnosis were also examined. Participants (n = 66) were randomly allocated to 10-weekly sessions of group-based CBT or CBTH. LMM analyses of ITT and Completer data at post-treatment, six-month and 12-month follow-up showed that both treatments were probably efficacious but we did not find significant differences between them. Analyses of remission and response to treatment data revealed that the CBTH Completer group significantly outperformed CBT at 12-month follow-up (p = .011). CBTH also displayed significantly higher associations between credibility, expectancy and mood outcomes up to 12-month follow-up (all p < .05 or better), while attitude to hypnosis showed one significant association (r = -0.57, p < .05). These results suggest that hypnosis shows promise as an adjunct in the treatment of MDD but a larger sample size is required to fully test its merits.

Redefining hypnosis: A narrative review of theories to move towards an integrative model

Hypnosis is an ancient mind-body intervention that has regained interest with the surge of research in the last decade documenting its clinical validity. Yet, theoretical controversies and misconceptions prevail among theorists, clinicians, and the general public, impeding the understanding, acceptance, replication, and use of hypnosis. Providing adequate information, which dispels misconceptions and promotes more balanced views, is warranted to facilitate the implementation and adoption of hypnosis in clinical and research settings. This review re-examines the conceptualisation of hypnosis throughout history and the theoretical controversies surrounding it while highlighting their meeting points and clinical implications. Despite dichotomies, a broad agreement appears across theoretical approaches regarding hypnotic analgesia effects, key components, and vocabulary. Further, theories highlight key factors of hypnotic responding. For instance, social theories highlight social and contextual variables, whereas state theories highlight biopsychosocial mechanisms and individual factors. Based on theories, the terms hypnotherapy or clinical hypnosis are recommended to refer to the therapeutic use of hypnosis in psychotherapeutic and medical contexts, respectively. This review concludes with a model that integrates various theories and evidence and presents hypnosis as a complex multifaceted intervention encompassing multiple procedures, phenomena, and influencing factors. This review intends to deepen our understanding of hypnosis, and promote its more rapid adoption and adequate implementation in research and clinical contexts, in addition to steering research towards evidence-based hypnotic practice. The review can have important research and clinical implications by contributing to advancing knowledge regarding hypnotic procedures, phenomena, and influencing factors.

Demystifying hypnosis: Unravelling facts, exploring the historical roots of myths, and discerning what is hypnosis

BACKGROUND AND PURPOSE

Hypnosis, a mind-body treatment dating back to early human history, has regained attention in the last decade, with research suggesting its effectiveness for varied physiological and psychological ailments such as distress, pain, and psychosomatic disorders. However, myths and misconceptions have prevailed among the general public and clinicians, hindering the adoption and acceptance of hypnosis. It is important to distinguish myths from facts and discern what is hypnosis and what is not to enhance the understanding, acceptance, and adoption of hypnotic interventions.

METHODS

This narrative review traces the history of myths surrounding hypnosis in contrast to the evolution of hypnosis as a treatment modality. In addition to comparing hypnosis to other interventions with similar procedures and features, the review unravels misconceptions that have impeded the adoption and acceptance of hypnosis in clinical and research settings and presents evidence to demystify this intervention.

RESULTS

This review examines the roots of myths while presenting historical facts and evidence that support hypnosis as a treatment modality and alleviate misconceptions depicting it as mystical. Further, the review distinguishes hypnotic and non-hypnotic interventions with overlapping procedures and phenomenological features to enhance our understanding of hypnotic techniques and phenomena.

CONCLUSION

This review enhances the understanding of hypnosis in historical, clinical, and research contexts by disproving related myths and misconceptions to promote the adoption of hypnosis in clinical and research contexts. Further, this review highlights knowledge gaps requiring further investigations to steer research toward an evidence-based practice of hypnosis and optimise multimodal therapies embedding hypnosis.

The nature and persistence of the effects of posthypnotic suggestions on food preferences: The final report of an online study

The persistence of food preferences, which are crucial for diet-related decisions, is a significant obstacle to changing unhealthy eating behavior. To overcome this obstacle, the current study investigates whether posthypnotic suggestions (PHSs) can enhance food-related decisions by measuring food choices and subjective ratings. After assessing hypnotic susceptibility in Session 1, at the beginning of Session 2, a PHS was delivered aiming to increase the desirability of healthy food items (e.g., vegetables and fruit). After the termination of hypnosis, a set of two tasks was administrated twice, once when the PHS was activated and once deactivated in counterbalanced order. The task set consisted of rating 170 pictures of food items, followed by an online supermarket where participants were instructed to select enough food from the same item pool for a fictitious week of quarantine. After 1 week, Session 3 mimicked Session 2 without renewed hypnosis induction to assess the persistence of the PHS effects. The Bayesian hierarchical modeling results indicate that the PHS increased preferences and choices of healthy food items without altering the influence of preferences in choices. In contrast, for unhealthy food items, not only both preferences and choices were decreased due to the PHS, but also their relationship was modified. That is, although choices became negatively biased against unhealthy items, preferences played a more dominant role in unhealthy choices when the PHS was activated. Importantly, all effects persisted over 1 week, qualitatively and quantitatively. Our results indicate that although the PHS affected healthy choices through resolve, i.e., preferred more and chosen more, unhealthy items were probably chosen less impulsively through effortful suppression. Together, besides the translational importance of the current results for helping the obesity epidemic in modern societies, our results contribute theoretically to the understanding of hypnosis and food choices.