Researchers at Stanford University say they’ve made the sort of discovery that you’d expect to see in a piece of science fiction. In a controlled and randomized trial published this week, they found evidence that people can be made more susceptible to hypnosis with just two short sessions of non-invasive brain stimulation. The findings suggest that brain stimulation could make hypnosis a more effective treatment for various health conditions like chronic pain, though more extensive research will be needed to know for sure.
While hypnosis may often be portrayed as either a preternatural feat of persuasion or a cheap parlor trick, the practice has a long history in medicine, particularly psychotherapy. It’s intended to help people reach a more focused and relaxed state of awareness—one in which people are more able to incorporate suggestions about changing certain behaviors or thought patterns. Hypnosis has been used to help people manage a variety of mental and physical conditions, though the evidence for its effectiveness is weaker for some health problems (for instance, quitting smoking) compared to others (irritable bowel syndrome).
One reason why the observed success rate of hypnosis might vary so wildly is that only some people truly respond well to it. Studies over the years have found that people’s susceptibility to hypnosis runs along a spectrum and remains fairly stable throughout adulthood, much like a personality trait. But lead study author Afik Faerman, a postdoctoral scholar in psychiatry at Stanford Medicine, and his colleagues wondered if this trait really is so immutable.
“The ability to experience suggestions in hypnosis (hypnotizability) is distributed in a bell-shaped curve across the population, with only about 20% considered highly hypnotizable,” Faerman told Gizmodo in an email. “We wanted to test if we could make the brains of people who were not highly hypnotizable act and function as if they were, hoping such a possibility would open the door for improving therapy.”
Based on some of the authors’ past research, they decided to focus on two areas of the brain associated with high hypnotizability: the dorsolateral prefrontal cortex, which helps us make decisions, and the anterior cingulate cortex, which is linked to our perception of stimuli. In more susceptible people, these areas seem to have greater functional connectivity, or communication, going on between them. The team used transcranial magnetic stimulation (TMS), which non-invasively sends electrical pulses to the brain through the scalp, to try amplifying this connection in their test subjects and hopefully boost their hypnotizability along with it.
The trial involved 80 patients with fibromyalgia, a chronic pain condition that hypnosis has shown some promise in helping to alleviate, who did not appear to be highly hypnotizable. The volunteers all underwent brain scans to find the best customized targets for TMS. Then they were randomly assigned into two groups, with one group receiving two 46-second bursts of TMS and the other a sham treatment (the same procedure was carried out, but no actual stimulation happened). Before and after these sessions, the volunteers were tested on their hypnotizability on a scale from one to ten.
Overall, the treatment group on average showed a clear improvement in their ability to be hypnotized, with a roughly one point increase in their scores afterward, while the placebo group showed no significant change. The change was temporary however; an hour later, the difference between groups had faded away.
The team’s findings, published Thursday in Nature Mental Health, are only intended to show a proof of concept for their method, which they’ve coined SHIFT (Stanford Hypnosis Integrated with Functional Connectivity-targeted Transcranial Stimulation).
“This study was designed to answer a mechanistic question—’Could it be done?’. Because of that, the stimulation protocol we used was very short. For reference, the shortest FDA-approved treatment for depression with TMS is 50 stimulation sessions of about 10 minutes each (overall ~500 minutes) across 5 consecutive days,” Faerman said. And now that they’ve shown that people’s hypnotic tendencies can be swayed, there’s plenty more work ahead.
The team is already developing an improved protocol in hopes of inducing big enough changes to people’s hypnotizability that would affect their response to it for conditions like fibromyalgia. And should this research continue to bear out, Faerman sees a wide open potential for hypnosis as a medical treatment.
“My vision, as a clinical psychologist, is that in the near future, patients will have a brief stimulation session before their therapy appointment to increase the effectiveness of treatment,” he said. “This will allow us to, first and foremost, offer effective, drug-free treatments and improve the well-being of our patients, but it will also save time and money for the patients and our healthcare system.”
