Scientists at Stanford University have discovered a method to temporarily enhance a person’s ability to be hypnotized using a non-invasive brain stimulation technique. This study, published in Nature Mental Health, predominantly women, shows significant potential for advancing treatments for pain management, particularly in individuals with fibromyalgia syndrome, a condition known for its chronic pain.
Hypnosis can play an important role in managing various psychiatric and neurological symptoms. Notably, hypnosis has been particularly effective in reducing pain. However, a key challenge has been the varying degrees of hypnotizability among individuals – essentially, how responsive they are to hypnosis. This variability is a stable trait influenced by cognitive, neural, and behavioral components.
Around two-thirds of adults show some level of hypnotizability, with about 15% being highly responsive. These high responders can achieve remarkable feats like undergoing surgeries without anesthesia solely under hypnosis. This variation in hypnotizability prompted the researchers to investigate if they could enhance a person’s responsiveness to hypnosis.
Previous attempts to modify this trait, using methods like psychoactive drugs or behavioral training, achieved limited success. The research team, therefore, turned to a novel approach: using targeted brain stimulation to influence the areas of the brain involved in hypnotizability.
“Evidence shows that clinical hypnosis is an effective drug-free approach to treat a variety of psychophysiological symptoms, particularly pain,” explained study author Afik Faerman (@AfikFaerman), an NIMH T32 Postdoctoral Fellow at Stanford University in the department of Psychiatry and Behavioral Sciences.
“Unfortunately, not everyone responds equally to hypnosis, and some people do not benefit as much from it as others. We wanted to test if we could make the brains of people who were not highly responsive to hypnosis act and function as if they were, hoping such a possibility would open the door for improving therapy.”
The study focused on individuals with fibromyalgia syndrome, a disorder characterized by widespread pain that is often resistant to traditional pain medications. The researchers chose this group because of the potential benefits they could reap from enhanced hypnotizability in pain management.
To conduct the study, the researchers first screened individuals for their baseline level of hypnotizability using the Hypnotic Induction Profile (HIP), a standardized assessment. They enrolled 80 participants who scored low to moderate on this scale, excluding those who were naturally highly hypnotizable. Alongside HIP, the researchers also employed the Hypnotic Intensity Scale (HIS) to gauge the depth of the hypnotic experience as perceived by the participants.
The core of the study involved a technique known as Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation (SHIFT). This method involves applying repetitive transcranial magnetic stimulation (rTMS) to specific areas of the brain associated with hypnotizability, particularly the left dorsolateral prefrontal cortex, a region linked to higher-order cognitive processes. TMS is a non-invasive procedure that uses magnetic fields to stimulate nerve cells in the brain.
“We tested SHIFT in people with fibromyalgia, a chronic pain disorder, because hypnosis has been shown to be effective in reducing pain, and higher hypnotizability is typically associated with better outcomes,” Faerman told PsyPost.
The participants were randomly assigned to receive either active or sham (placebo) stimulation. The active group underwent a brief, targeted SHIFT session, while the sham group received a simulation of the treatment without the actual brain stimulation. The sessions were designed to be short, lasting only around a minute and a half.
After the stimulation, the researchers reassessed the participants’ hypnotizability using the HIP. They found that those who received the active SHIFT treatment showed a significant increase in their hypnotizability scores immediately after the session. This change, however, appeared to be short-lived. When reassessed approximately an hour later, the increase in hypnotizability in the active group, though still present, was reduced and not significantly different from the sham group.
“We developed an individualized neuroimaging-based noninvasive brain stimulation, termed SHIFT,” Faerman explained. “We found that active SHIFT was associated with increased hypnotizability (responsiveness to hypnosis), while sham stimulation did not. We were excited to learn that it could actually be done, even though we hypothesized that SHIFT would work!”
Furthermore, there were no notable changes in the subjective experience of hypnotic depth as measured by the HIS, suggesting that while the participants’ responsiveness to hypnosis increased, their perception of being hypnotized did not change significantly.
“I found it interesting that participants’ guesses of whether they received active or sham stimulation was not significantly associated with the actual change in their hypnotizability,” Faerman told PsyPost.
But the study, like all research, includes some limitations. First, the effects of the SHIFT stimulation on hypnotizability were transient, indicating that any clinical applications would need to be closely timed with the stimulation. Secondly, the study did not explore the impact of this increased hypnotizability on actual symptoms of Fibromyalgia Syndrome, as it was primarily focused on the mechanism of enhancing hypnotizability.
Looking ahead, the research team emphasizes the need for further studies to explore the long-term effects and potential clinical applications of this technique. They suggest investigating whether different durations or intensities of stimulation could produce more sustained increases in hypnotizability. Also, future research could examine whether similar brain stimulation techniques could be effective in other conditions, potentially broadening the therapeutic applications of hypnosis.
“We designed the study using a strong tool in clinical research – a double-blind randomized controlled trial, to answer a mechanistic question – ‘could it be done?’ Because of that, the stimulation protocol we used was very brief – only 92 seconds,” Faerman explained.
“For reference, our TMS treatment for depression (SNT/SAINT), which was recently cleared by the FDA, takes about 500 minutes (over 5 days) to complete. Now that our study has answered the question, and we know it can be done, we are working on designing and testing a clinical adaptation to SHIFT to achieve the most clinically applicable intervention.”
“My vision, as a clinical psychologist, is that patients will have a brief stimulation session to increase the effectiveness of treatment before their therapy appointment,” Faerman said. “This will allow us to offer effective drug-free treatments and improve our patients’ well-being, and also to save time and money for our patients and the healthcare system.”
The study, “Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation (SHIFT): a preregistered randomized controlled trial“, was authored by Afik Faerman, James H. Bishop, Katy H. Stimpson, Angela Phillips, Merve Gülser, Heer Amin, Romina Nejad, Danielle D. DeSouza, Andrew D. Geoly, Elisa Kallioniemi, Booil Jo, Nolan R. Williams, and David Spiegel.