Hypnosis in psychotherapy, psychosomatics and medicine. A brief overview.

Aspects of hypnosis and its application in psychotherapy, psychosomatics and medicine are examined and contextualized in the 250-year history of hypnosis. Imagination as an essential element of hypnotic treatments appeared as early as 1784 as an argument rejecting the theory of animal magnetism of Franz Anton Mesmer. In somnambulism of German romanticism, another proto-form of hypnosis after 1800, concepts of the mind-body problem were dealt with, which still characterize the understanding of unconscious mental processes today. Hypnosis was at the beginning of psychoanalysis, but was not pursued further by Sigmund Freud from 1900 onwards. Nevertheless, there were some hypnoanalytical approaches in the 20th century, as well as attempts to integrate hypnosis into behavior therapy. Techniques of imagination and relaxation combine both; in particular findings from cognitive psychology explain processes of both hypnosis and cognitive behavioral therapy. The influence of social psychology brought a new perspective to the debate about the nature of hypnosis, which continues to this day: is hypnosis to be understood as a special state of consciousness or is it a completely normal, mundane interaction? The experiments that were carried out to support one side or the other were also dependent on the hypnotizability of the subjects involved, as the more difficult hypnotic phenomena such as paralysis, hallucinations or identity delusions can only be demonstrated by highly hypnotizable subjects. The fact that these are not mere compliance reactions has now been proven by many studies using imaging techniques. But even those who are moderately hypnotizable benefit from hypnosis rituals. Variables postulated by socio-cognitive hypnosis researchers, such as motivation and expectation, are relevant, as is a good "hypnotic rapport." Practical application of hypnotherapy today is characterized by the innovative techniques and strategies developed by Milton H. Erickson. Research into the effectiveness of hypnosis in the field of psychotherapy and psychosomatics still leaves much to be done. The situation is different in the field of medical hypnosis, where there are considerably more studies with a satisfactory design and verifiable effects. However, the impact in practical application in everyday medical practice is still low. Newer developments such as virtual reality and artificial intelligence are being looked at with critical interest.

Intimate relationships and hypnosis: insecure adult attachment affects emotions and absorption during hypnosis.

Introduction: Hypnosis research indicates that subjects are not equally hypnotizable. Most studies on hypnotizability focused on the relationships with personality or cognitive variables. At the same time, only a few proposed the contribution of the attachment style, defined as the result of the childhood relationship with the caregivers and influencing the adult relations. Methods: In the present investigation, two studies were carried out to test the possible association between adult attachment and hypnotic responsivity. The adult attachment was assessed using the Experiences in Close Relationships-Revised (ECR-R) questionnaire, while hypnosis was assessed through the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A; Study 1) and the Phenomenology of Consciousness Inventory: Hypnotic Assessment Procedure (PCI-HAP; Study 2) in order to adopt a behavioral and a phenomenological approach, respectively. Results: Analyses showed that attachment factors (anxiety and avoidance) were not associated with the level of hypnotizability, whereas it was associated with variations of consciousness during hypnosis, mainly internal dialogue, absorption and negative emotions. Overall, the insecure attachment styles yielded increased mind wandering and restlessness during hypnosis when compared to the secure style. The reason probably lies in the feeling of anxiety or danger of insecurely attached individuals when involved in intimate or confidential relationships. Conclusion: These findings clarify a still poorly investigated aspect concerning the influence of attachment style on hypnotic experience and further highlight the need to consider inter-individual differences and the phenomenological perspective when assessing hypnosis and hypnotizability.

Interoception as a function of hypnotizability during rest and a heartbeat counting task.

The hypnotizability-related differences in morpho-functional characteristics of the insula could at least partially account for the differences in interoceptive accuracy (IA) observed between high and low hypnotizable individuals (highs, lows). Our aim was to investigate interoceptive processing in highs, lows, and medium hypnotizable individuals (mediums), who represent most of the population, during a 10-minute open eyes relaxation condition (Part 1) and three repetitions of consecutive 2-minute open eyes, closed eyes, and heartbeat counting conditions, followed by a 2-minute post-counting condition (Part 2). Electrocardiogram and electroencephalogram were recorded in 14 highs, 14 mediums, and 18 lows, classified according to the Stanford Hypnotic Susceptibility Scale: Form A. Heartbeat-evoked cortical potentials (HEP) were extracted throughout the entire session, and IA index was obtained for the heartbeat counting task (HCT). In Part 1, significant hypnotizability-related differences were observed in the right central region in both early and late HEP components, with lows showing positive amplitudes and highs/mediums showing negative amplitudes. In Part 2, the same group differences were limited to the early component. Moreover, in the left frontal regions, only mediums modified their HEP during the counting task with respect to the open/closed eyes conditions, whereas highs displayed HEP differences between counting and post-counting rest. HCT did not show significant group differences. In conclusion, highs and mediums seem to be more similar than mediums and lows regarding HEP, despite the absence of significant differences in HCT. Nonetheless, a negative correlation between hypnotizability scores and HEP amplitudes was observed in the regions showing group differences.

Brain Functional Correlates of Resting Hypnosis and Hypnotizability: A Review.

This comprehensive review delves into the cognitive neuroscience of hypnosis and variations in hypnotizability by examining research employing functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and electroencephalography (EEG) methods. Key focus areas include functional brain imaging correlations in hypnosis, EEG band oscillations as indicators of hypnotic states, alterations in EEG functional connectivity during hypnosis and wakefulness, drawing critical conclusions, and suggesting future research directions. The reviewed functional connectivity findings support the notion that disruptions in the available integration between different components of the executive control network during hypnosis may correspond to altered subjective appraisals of the agency during the hypnotic response, as per dissociated and cold control theories of hypnosis. A promising exploration avenue involves investigating how frontal lobes' neurochemical and aperiodic components of the EEG activity at waking-rest are linked to individual differences in hypnotizability. Future studies investigating the effects of hypnosis on brain function should prioritize examining distinctive activation patterns across various neural networks.

Hypnotizability-related risky experience and behavior.

Risk is the probability of an adverse event. The proneness to take a risk and the risk taking behavior differ among the general population. Hypnotizability is a stable psychophysiological trait expressing the individual proneness to modify perception, memory and behavior following specific suggestions also in the ordinary state of consciousness. Some hypnotizability-related neurophysiological and behavioral correlates suggest that hypnotizability level, measured by standard scales classifying individuals as low (lows), medium (mediums) and high hypnotizable (highs) subjects, can be related to risk propensity and risk-taking. To study whether hypnotizability modulates risk propensity and behavior, we recruited healthy participants, classified through the Standford Hypnotic Susceptibility scale, form A, and compared lows' (n = 33), mediums' (n = 19) and highs'(n = 15) experiential and behavioral risk perception and propensity variables through the Domain-specific risk-taking scale and the Balloon Analogue Risk Task. MANOVA results indicated that different hypnotizability levels are not associated with different risky behavior and experience, except for higher expected financial benefits from risky behavior in lows. However, hypnotizability-related risk profiles were identified through correlational analyses. In fact, highs exhibited a negative association between risk perception and propensity to risk-taking, whereas mediums and lows displayed a positive association between risk propensity and expected benefit. In conclusion, the highs' profile indicates a more automatic behavior with respect to mediums and lows.

Treating Hot Flashes with Hypnosis: Does Hypnotizability Modulate Reductions?

Hypnosis is an effective treatment option for a variety of concerns. Past research has suggested that those who score in the high range of hypnotizability initially show greater improvement than those in the low range. A post hoc analysis was conducted to examine the extent to which hypnotizability modulates the reduction of hot flash frequency. Average number of hot flashes reported during hypnosis treatment and a 12-week follow-up were grouped according to participants' level of hypnotizability. Using baseline data, the reduction percentage of hot flash frequency was plotted and visually examined to determine when a clinically significant reduction (50%) in hot flashes was reached. Our results suggested that, regardless of hypnotizability, participants ultimately obtained a 50% reduction in hot flash frequency. Interestingly, participants who were rated as either moderately or highly hypnotizable achieved a 50% reduction by Week 3 while those of low hypnotizability did not cross the 50% reduction threshold until the 12-week follow-up. Implications from these findings include the importance of assessing hypnotizability in clinical settings to better tailor treatment dose and expectations.

What is the Source of Hypnotic Responses?

The author proposes that hypnosis is a culture-bound concept that has misattributed - to suggestion and hypnosis - the functioning of a natural, freestanding, human ability to alter personal experience. The 18th-century attribution of these phenomena (to the suggestions of a magnetizer) continues today because science and Western culture still do not explicitly acknowledge that humans possess a natural capacity to intentionally alter their own experiences. Like every other human ability (e.g. athletic, artistic, musical, mathematical, etc.), utilization of the natural human ability to intentionally alter one's personal experience does not require suggestion, trance, or hypnotic induction. This ability has been studied for over 200 years under the conceptual aegis of suggestibility and hypnosis. As a consequence, the phenomena of this freestanding ability have been veiled and conflated with hypnosis, suggestion, suggestibility, and hypnotizability. One serious consequence of this conflation is an underdeveloped, nomological network of hypnosis-centric concepts that has impeded the integration of hypnosis with the rest of science.

Confirmatory Factor Analysis of the Elkins Hypnotizability Scale in a Clinical Population.

The objective of this study was to determine the best-fit factor structure of a standardized hypnotizability measure in a clinical population. The Elkins Hypnotizability Scale (EHS) was administered to 173 post-menopausal women, age from 39 to 75 years, with a mean age of 54.61 years. Confirmatory factor analysis was conducted, and comparative fit index (CFI) and root mean square error of approximation (RMSEA) were used to determine goodness of fit. Results indicated that the single-factor structure modeled with six indicators based on the individual items on the EHS provides the best description of fit. Results of the present study demonstrate that the EHS has a single-factor structure. Further research is required with other populations and measures.

Immediate hypnosis effects and outcome predictors in chronic nociplastic pain.

This study used data from a randomized controlled trial on the efficacy of hypnosis with analgesic suggestions relative to hypnosis with nonspecific suggestions to explore two areas. The first was the immediate effects of each hypnosis session and their relevance to the treatment induced change in pain intensity. The second was the identification of variables associated with the beneficial effects of hypnosis treatment in the form of reducing pain intensity and pain quality. The predictive value of the initial treatment response, hypnotizability, and the dichotomous variable of pain medication use were examined. Both interventions resulted in similar significant reductions in pain intensity after each session, but without a cumulative effect. The initial response correlated positively and moderately with pain intensity decreases induced by the complete hypnosis treatment. There was only a weak association between hypnotizability and pain quality improvement. Only participants not taking pain medications achieved a meaningful reduction in pain outcomes. Each hypnosis session results in an immediate reduction in chronic nociplastic pain intensity, and a fruitful first session may be a positive signal to continue therapy. Even patients with low hypnotizability can obtain beneficial outcomes. Pain medication use may become a new predictor in hypnosis research, as significant decreases in pain intensity and pain quality occurred only in the absence of pharmacotherapy. However, the results of this study require confirmation in further research with longer treatment periods.

Reliability and Validity of the Elkins Hypnotizability Scale within a Clinical Sample.

Hypnotherapy is used in clinical settings to treat mental and physical health-related conditions. Hypnotic response can be measured through hypnotizability scales to help interventionists personalize treatment plans to suit the patients' individualized hypnotic abilities. Examples of these scales are the Elkins Hypnotizability Scale (EHS) and the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C). According to the previous literature, these scales have good discriminating ability and internal consistency (α = 0.85) in collegiate samples, but the psychometric properties of the EHS for a targeted clinical population have not been determined yet. This study assessed said properties, and results showed adequate reliability of the EHS in a targeted clinical sample and strong convergent validity of the EHS to the SHSS:C. The authors conclude that the EHS is a strong and useful measure of hypnotizability that is pleasant, safe, brief, and sensible to individualities in hypnotic ability found in diverse clinical samples.

Transcranial electrical stimulation of the prefrontal cortex to boost the hypnosis experience: who benefits most?

Many attempts have been made to enhance hypnotizability. The most recent studies adopted the non-invasive brain stimulation to deactivate the dorsolateral prefrontal cortex (DLPFC) during hypnosis, indicating this as a promising approach. However, it is still no clear whether individual factors can predict the effects of stimulation on hypnotizability. In the present study we adopted the phenomenological consciousness inventory (PCI) to retrospectively assess the mental processes during hypnosis and to predict hypnotizability, here defined as "hypnoidal state." The aim was to investigate the possible role of the hypnotic susceptibility on the efficacy of a validated approach of hypnosis enhancement through cathodal transcranial electrical stimulation (tDCS) of the left DLPFC. Results indicated that the lower hypnoidal state at baseline predicted the greater enhancement after the active tDCS. These findings suggest the subjects with lower hypnotic responsiveness as the best candidates for the tDCS interventions of hypnosis enhancement, at least for the montage targeting the left DLPFC. Neurocognitive underpinnings and clinical implications of the results are discussed.

Association of Hypnotizability, Interoception, and Emotion.

The present scoping review reports the reciprocal relations between hypnotizability, interoception, and emotion. Brain morpho-functional differences may account for the lower interoceptive accuracy, higher interoceptive sensitivity, and different emotional strategies observed in highly hypnotizable participants with respect to medium-to-low hypnotizables. Since interoception is relevant to both physical and mental health and hypnotizability can predict both interoceptive abilities and the efficacy of interoception-based mental training, this allows for the development of new forms of treatment and rehabilitation.

Is Hypnotic Induction Necessary to Experience Hypnosis and Responsible for Changes in Brain Activity?

The relevance of formal hypnotic induction to the experience of trance and its neural correlates is not clear, in that hypnotizability, beliefs and expectation of hypnosis may play a major role. The aim of the study was assessing the EEG brain activity of participants with high (highs) or low hypnotizability scores (lows), aware of their hypnotizability level and informed that the session will include simple relaxation, formal hypnotic induction and neutral hypnosis. A total of 16 highs and 15 lows (according to the Stanford Hypnotic Susceptibility Scale, form A) were enrolled. Their EEGs were recorded during consecutive conditions of open/closed-eyes relaxation, hypnotic induction, neutral hypnosis and post hypnosis not interrupted by interviews. The studied variables were theta, alpha and gamma power spectral density (PSD), and the Determinism (DET) and Entropy (ENT) of the EEG signal Multidimensional Recurrence Plot (mRP). Highs reported significantly greater changes in their state of consciousness than lows across the session. The theta, alpha and gamma PSD did not exhibit condition-related changes in both groups. The Alpha PSD was larger in highs than in lows on midline sites, and the different sides/regions' theta and gamma PSD were observed in the two groups independently from conditions. ENT showed no correlation with hypnotizability, while DET positively correlated with hypnotizability during hypnosis. In conclusion, the relevance of formal hypnotic induction to the experience of trance may be scarce in highs, as they are aware of their hypnotizability scores and expecting hypnosis. Cognitive processing varies throughout the session depending on the hypnotizability level.

Modulation of the heartbeat evoked cortical potential by hypnotizability and hypnosis.

Hypnotizability is a psychophysiological trait measured by scales and associated with several differences, including interoceptive accuracy and the morpho-functional characteristics of interoception-related brain regions. The aim of the study was to assess whether the amplitude of the heartbeat evoked cortical potential (HEP), a correlate of interoceptive accuracy, differs in participants with low (lows) and high (highs) hypnotizability scores (assessed by the Stanford Hypnotic Susceptibility Scale, Form A) before and after the induction of hypnosis. ECG and EEG were monitored in 16 highs and 15 lows during an experimental session, including open eyes baseline (B), closed eyes relaxation (R), hypnotic induction (IND), neutral hypnosis (NH), and post session baseline (Post). No significant difference was observed between groups and conditions in autonomic variables. The HEP amplitude was lower in highs than in lows at the right parietal site, likely due to hypnotizability related differences in the functional connection between the right insula and parietal cortex. It increased in highs and decreased in lows across the session, possibly due to the highs' preeminently internally directed attention and to the lows' possible disengagement from the task. Since interoception is involved in several cognitive-emotional functions, its hypnotizability related differences may contribute to the variability of experience and behavior in daily life.

Alteration of hypnotic experience following transcranial electrical stimulation of the left prefrontal cortex

Background: Recent studies of neurostimulation reported alteration of hypnotizability and hypnotic phenomena after inhibition of the dorsolateral prefrontal cortex (DLPFC), but the different assessments of hypnosis and the stimulation parameters still left open many questions about the role of this brain region in hypnotizability. We aimed to administer inhibitory transcranial direct current stimulation (tDCS) over the left DLPFC to observe effects of stimulation on the hypnotic experience and the feeling of agency. Methods: a procedure of hypnotic induction with suggestions was repeated twice: before and after the unilateral cathodal tDCS over the left DLPFC. The experience was assessed through a phenomenological assessment of hypnosis and sense of agency in thirty-three participants randomly assigned to the sham or the active group. Results: active (inhibitory) tDCS enhanced the hypnotizability by 15.4% and altered a few dimensions of consciousness such as self-awareness and absorption. No changes emerged on the feeling of agency and pass rates for suggestions. Conclusions: tDCS reflects a promising tool to alter the hypnotic phenomena and the responsiveness to hypnotic procedures. Neurocognitive implications are discussed for the construct of hypnotizability as well as for the role of the left DLPFC in the dimensions of consciousness such as self-awareness. (AU)

Hypnotizability and Disordered Personality Styles in Cluster A Personality Disorders.

AIM: Interpersonal sensitivity and mistrust are the main characteristics of cluster A personality disorders (CAPD) which might be due to the high accessibility to negative suggestions from environments. Yet the exact associations between hypnotic suggestibility and their personality disorder functioning styles remain unclear. METHODS: We invited 36 patients with CAPD and 115 healthy volunteers to undergo the Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C) and Parker Personality Measure (PERM). RESULTS: Compared to controls; patients scored higher on PERM paranoid; schizoid; schizotypal; borderline; avoidant; and dependent styles; on the SHSS:C total and "challenge suggestions", and the passing rates of "hand lowering", "arm rigidity", "dream", and "arm immobilization". In patients, "dream" negatively predicted the schizoid; "hallucinated voice" negatively the schizotypal; "mosquito hallucination" positively the histrionic and dependent; and "arm immobilization" negatively the avoidant style. CONCLUSIONS: Our results suggested that the insusceptibility to perceptual suggestions from others and the high control over body contribute to the paranoid attitude and interpersonal avoidance in CAPD. These findings help to understand the cause of interpersonal problems in these patients and suggest the trial of hypnotherapy for them.

Alteration of hypnotic experience following transcranial electrical stimulation of the left prefrontal cortex.

Background: Recent studies of neurostimulation reported alteration of hypnotizability and hypnotic phenomena after inhibition of the dorsolateral prefrontal cortex (DLPFC), but the different assessments of hypnosis and the stimulation parameters still left open many questions about the role of this brain region in hypnotizability. We aimed to administer inhibitory transcranial direct current stimulation (tDCS) over the left DLPFC to observe effects of stimulation on the hypnotic experience and the feeling of agency. Methods: a procedure of hypnotic induction with suggestions was repeated twice: before and after the unilateral cathodal tDCS over the left DLPFC. The experience was assessed through a phenomenological assessment of hypnosis and sense of agency in thirty-three participants randomly assigned to the sham or the active group. Results: active (inhibitory) tDCS enhanced the hypnotizability by 15.4% and altered a few dimensions of consciousness such as self-awareness and absorption. No changes emerged on the feeling of agency and pass rates for suggestions. Conclusions: tDCS reflects a promising tool to alter the hypnotic phenomena and the responsiveness to hypnotic procedures. Neurocognitive implications are discussed for the construct of hypnotizability as well as for the role of the left DLPFC in the dimensions of consciousness such as self-awareness.

The influence of experience and modality of presentation (online vs. offline) on hypnotizability.

Introduction: Hypnotizability is conceptualized as a stable personality trait describing the ability to respond to suggestions given under hypnosis. Hypnotizability is a key factor in explaining variance in the effects of hypnotic suggestions on behavior and neural correlates, revealing robust changes mostly in high hypnotizable participants. However, repeated experience and training have been discussed as possible ways to increase willingness, motivation, and ability to follow hypnotic suggestions, although their direct influence on hypnotizability are still unclear. Additionally, it is important whether hypnotizability can be assessed reliably online. Methods: We investigated the influence of the degree of experience with hypnosis and the presentation mode (online versus live) on the stability of hypnotizability in two groups of 77 and 102 young, healthy students, respectively. The first group was tested twice with the Harvard Group Scale of Hypnotic Susceptibility (HGSHS) after two weeks. During this period, participants either repeatedly listened to a hypnosis or trained on a progressive muscle relaxation or served as waitlist control group. In the secondgroup, participants performed both an online or offline version of the HGSHS, with varying time intervals (1-6 weeks). Results: Contrary to our expectations, hypnotizability declined from the first to second assessment in the first group. The reductionwas most prominent in initially highly hypnotizable subjects and independent of the experience intervention. We observed a similar reduction of hypnotizability in the second group, independent of presentation modality. The reduction was again driven by initially highly hypnotizable subjects, while the scores of low hypnotizable subjects remained stable. The presentation modality (online vs. offline) did not influence HGSHS scores, but the test-retest reliability was low to moderate (rtt = 0.44). Discussion: Our results favor the conclusion that generally, hypnotizability is a relatively stable personality trait which shows no major influence of preexperience or modality of assessment. However, particularly highly hypnotizable subjects are likely to experience a decline in hypnotizability in a retest. The role of the concrete assessment tool, psychological factors, and interval length are discussed. Future studies should replicate the experiments in a clinical sample which might have higher intrinsic motivation of increasing responsiveness toward hypnotic interventions or be more sensitive to presentation mode.

Feasibility of the Elkins Hypnotizability Scale-Spanish Translation.

The absence of a Spanish translation of the Elkins Hypnotizability Scale (EHS) suggests access to clinical research and hypnotic interventions may be limited for those in predominantly Spanish-speaking populations. The present study aims to mitigate this disparity by providing a translation of the EHS to facilitate participation in experimental research and clinical care in Spanish-speaking communities. The EHS was translated and administered to 9 participants. No major modifications were done to the characteristics or structure of the EHS after translation. To assess feasibility, mean hypnotizability levels and self-reported levels of pleasantness and comprehension were observed and compared to the English EHS. The results provide a Spanish translation of the EHS. This study demonstrates the Spanish translation of the EHS is feasible for further research.

Hypnotizability May Relate to Interoceptive Ability to Accurately Perceive Sleep Depth: An Exploratory Study.

When individuals score high on hypnotizability, they usually report experiencing an altered state of consciousness, physiological changes, and attentional shifts during hypnotic induction procedures as well. We hypothesize that a better interoception of such internal changes is also relevant for accurate sleep perception. We compared subjects scoring high versus low on hypnotizability to the accuracy of their estimations of Sleep Onset Latency (SOL) time awake, and sleep depth and explored their objective sleep. We sampled seven studies performed in our sleep labs across a midday nap or a night resulting in n = 231 subjects (aged 30.11 (SD = 17.02) years, range 18-82 with 15.2% males). Hypnotizability did not influence the accuracy of the perception of time needed to fall asleep or time spent awake. However, the reported sleep depth correlated significantly with the measured amount of slow-wave sleep in high hypnotizables. This pattern appeared across a nap as well as a whole night's sleep studies. We did not find any significant differences in objective sleep patterns depending on hypnotizability. Probably, high hypnotizables benefit from a better interoceptive ability for their perception of their sleep depth.