Unlocking hypnotizability: Transcranial brain stimulation for enhanced impact in chronic pain
Authors: Serge Marchand
Journal: Cell Reports Medicine (2024)

Hypnosis provides a therapeutic option for health issues like chronic pain, but individual responsiveness, termed hypnotizability, varies. Faerman et al.'s1Faerman A. Bishop J.H. Stimpson K.H. Phillips A. Gülser M. Amin H. Nejad R. DeSouza D.D. Geoly A.D. Kallioniemi E. et al.Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation (SHIFT): a preregistered randomized controlled trial.Nat. Ment. Health. 2024; 2: 96-103https://doi.org/10.1038/s44220-023-00184-zGoogle Scholar study showed that transcranial magnetic stimulation (TMS) can significantly improve hypnotizability, offering potential for patients with limited response to hypnosis in pain management. Hypnosis provides a therapeutic option for health issues like chronic pain, but individual responsiveness, termed hypnotizability, varies. Faerman et al.'s1Faerman A. Bishop J.H. Stimpson K.H. Phillips A. Gülser M. Amin H. Nejad R. DeSouza D.D. Geoly A.D. Kallioniemi E. et al.Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation (SHIFT): a preregistered randomized controlled trial.Nat. Ment. Health. 2024; 2: 96-103https://doi.org/10.1038/s44220-023-00184-zGoogle Scholar study showed that transcranial magnetic stimulation (TMS) can significantly improve hypnotizability, offering potential for patients with limited response to hypnosis in pain management. Hypnotherapy has been a long-standing practice in psychiatry and diverse health contexts, notably as an early intervention for functional neurological disorder (FND), which is characterized by unexplained neurological symptoms.2Connors M.H. Quinto L. Deeley Q. Halligan P.W. Oakley D.A. Kanaan R.A. Hypnosis and suggestion as interventions for functional neurological disorder: A systematic review.Gen. Hosp. Psychiatry. 2024; 86: 92-102https://doi.org/10.1016/j.genhosppsych.2023.12.006Google Scholar Extensive research has underscored hypnosis's efficacy across various psychological and somatic conditions, reporting high satisfaction levels, particularly in addressing stress, anxiety, and pain.3Rosendahl J. Alldredge C.T. Haddenhorst A. Meta-analytic evidence on the efficacy of hypnosis for mental and somatic health issues: a 20 year perspective.Front. Psychol. 2023; 141330238https://doi.org/10.3389/fpsyg.2023.1330238Google Scholar Studies have also delved into its effectiveness in managing acute procedural pain4Geagea D. Tyack Z. Kimble R. Polito V. Ayoub B. Terhune D.B. Griffin B. Clinical Hypnosis for Procedural Pain and Distress in Children: A Scoping Review.Pain Med. 2023; 24: 661-702https://doi.org/10.1093/pm/pnac186Google Scholar and chronic musculoskeletal and neuropathic pain,5Langlois P. Perrochon A. David R. Rainville P. Wood C. Vanhaudenhuyse A. Pageaux B. Ounajim A. Lavallière M. Debarnot U. et al.Hypnosis to manage musculoskeletal and neuropathic chronic pain: A systematic review and meta-analysis.Neurosci. Biobehav. Rev. 2022; 135104591https://doi.org/10.1016/j.neubiorev.2022.104591Google Scholar reflecting its broad applicability and therapeutic potential. Understanding the mechanisms of hypnosis remains an ongoing challenge, as hypnotizability varies among individuals, with approximately 10%–15% exhibiting high hypnotizability and 15%–20% falling into the low hypnotizability range.6Surman O.S. Baer L. Hypnosis.in: Stern T.A. Rosenbaum J.F. Fava M. Biederman J. Rauch S.L. Massachusetts General Hospital Comprehensive Clinical Psychiatry. Mosby, 2008: 183-188https://doi.org/10.1016/B978-0-323-04743-2.50017-2Google Scholar Given hypnotizability's stable nature, altering it presents a challenge due to its inherent characteristics. Recent studies have investigated the neural correlates of hypnosis, with the dorsolateral prefrontal cortex (DLPFC) emerging as a key region of interest. Using transcranial direct cortical stimulation (tDCS), Perri and colleagues successfully enhanced hypnotizability, as measured by the phenomenology of consciousness inventory—hypnotic assessment procedure (PCI-HAP), in a cohort of healthy subjects.7Perri R.L. Perrotta D. Rossani F. Pekala R.J. Boosting the hypnotic experience. Inhibition of the dorsolateral prefrontal cortex alters hypnotizability and sense of agency. A randomized, double-blind and sham-controlled tDCS study.Behav. Brain Res. 2022; 425113833https://doi.org/10.1016/j.bbr.2022.113833Google Scholar Complex chronic pain conditions like fibromyalgia, which often exhibit limited response to pharmacological or conventional medical treatments, present favorable opportunities for non-pharmacological interventions like hypnotherapy.8Schein B. Beltran G. França B.R. Sanches P.R.S. Silva Jr., D.P. Torres I.L. Fegni F. Caumo W. Effects of Hypnotic Analgesia and Transcranial Direct Current Stimulation on Pain Tolerance and Corticospinal Excitability in Individuals with Fibromyalgia: A Cross-Over Randomized Clinical Trial.J. Pain Res. 2023; 16: 187-203https://doi.org/10.2147/JPR.S384373Google Scholar While hypnosis can yield significant effects, variability in individual response, akin to other treatment modalities, remains a challenge. The Elkins hypnotizability scale (EHS) is commonly used to gauge one's susceptibility to hypnosis: patients who score low on this index are potentially less suitable candidates for hypnotherapy. Faerman and colleagues conducted a study utilizing transcranial brain stimulation to modulate hypnotizability, employing a paradigm called Stanford hypnosis integrated with functional connectivity-targeted transcranial stimulation (SHIFT).1Faerman A. Bishop J.H. Stimpson K.H. Phillips A. Gülser M. Amin H. Nejad R. DeSouza D.D. Geoly A.D. Kallioniemi E. et al.Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation (SHIFT): a preregistered randomized controlled trial.Nat. Ment. Health. 2024; 2: 96-103https://doi.org/10.1038/s44220-023-00184-zGoogle Scholar This individualized transcranial magnetic stimulation (TMS) targeted brain regions previously implicated in hypnotizability. Transcranial brain stimulation, utilized across various paradigms, serves both as a research tool for investigating brain regions and as a therapeutic approach, particularly in psychiatric conditions like depression, by modulating neuronal activity based on stimulation parameters. Drawing from previous research on brain regions involved in hypnosis, they targeted the left DLPFC to enhance connectivity with the dorsal part of the anterior cingulate cortex (dACC), known for its role in various functions, including responsiveness to hypnosis.8Schein B. Beltran G. França B.R. Sanches P.R.S. Silva Jr., D.P. Torres I.L. Fegni F. Caumo W. Effects of Hypnotic Analgesia and Transcranial Direct Current Stimulation on Pain Tolerance and Corticospinal Excitability in Individuals with Fibromyalgia: A Cross-Over Randomized Clinical Trial.J. Pain Res. 2023; 16: 187-203https://doi.org/10.2147/JPR.S384373Google Scholar,9Perri R.L. Di Filippo G. Transcranial electrical stimulation of the prefrontal cortex to boost the hypnosis experience: who benefits most?.Front. Psychol. 2023; 141217396https://doi.org/10.3389/fpsyg.2023.1217396Google Scholar The results were conclusive: compared to sham stimulation, patients receiving TMS exhibited a significant increase in their hypnotizability as measured by the EHS. These findings hold significant implications, particularly given the common lack of responsiveness of fibromyalgia to pharmacological interventions alongside its demonstrated positive response to hypnosis.8Schein B. Beltran G. França B.R. Sanches P.R.S. Silva Jr., D.P. Torres I.L. Fegni F. Caumo W. Effects of Hypnotic Analgesia and Transcranial Direct Current Stimulation on Pain Tolerance and Corticospinal Excitability in Individuals with Fibromyalgia: A Cross-Over Randomized Clinical Trial.J. Pain Res. 2023; 16: 187-203https://doi.org/10.2147/JPR.S384373Google Scholar,10Haanen H.C. Hoenderdos H.T. van Romunde L.K. Hop W.C. Mallee C. Terwiel J.P. Hekster G.B. Controlled trial of hypnotherapy in the treatment of refractory fibromyalgia.J. Rheumatol. 1991; 18: 72-75Google Scholar Replication studies within the same population and across other chronic pain conditions are warranted. Furthermore, investigations measuring both hypnotizability and clinical responses are crucial, offering insight into whether the observed increase in perceived hypnotizability correlates with enhanced therapeutic effects. After decades of research aimed at elucidating the neurophysiology of pain and extensive investment in developing new pharmacological approaches for various pain conditions, it has become evident that there is no singular pharmacological treatment for complex conditions like fibromyalgia and other chronic pain disorders. Given the significant role of the affective component of chronic pain experiences, pain therapeutics necessitate a multidimensional approach. Hypnosis, as a versatile therapeutic modality, has the potential to address diverse pain components and can be tailored to individual patient characteristics. Therefore, identifying methods for enhancing responsiveness to hypnosis in patients who are poor or non-responders holds profound clinical implications. Faerman and colleagues' study, utilizing TMS to augment hypnotizability, represents a promising advancement and opens avenues for future clinical research across various chronic pain conditions. In conclusion, Faerman et al.'s study illuminates the potential of TMS targeting the left DLPFC to enhance the effectiveness of hypnosis in individuals with fibromyalgia syndrome. Further research is imperative for exploring the relationship between heightened hypnotizability and therapeutic outcomes across fibromyalgia and other chronic pain conditions, thereby confirming the synergistic potential of hypnosis and TMS in clinical applications. The author received no financial benefits and has no contact with the authors of the article reviewed in this spotlight.