Experts who investigated the impact of a patient’s own beliefs about whether the treatment they are receiving for depression is real or fake have described their findings as “truly eye-opening”.
Outcomes can vary despite people receiving uniform treatment for conditions such as depression and now researchers have said this may be explained in part by a person’s own beliefs about the treatment they’re receiving.
A better understanding around this issue could help to improve treatments in the future, the research team says.
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Led by Professor Roi Cohen Kadosh from the University of Surrey, a team of psychologists analysed five studies to investigate the impact of patients’ subjective beliefs when it comes to neurostimulation treatments.
The conditions covered by the studies included ADHD and depression. Healthy adults were also participants in the studies.
The researchers’ key finding was that in four out of the five studies, patients’ beliefs around whether their treatment was real or placebo explained the outcomes.
There were several examples of when participants’ beliefs explained the results of the treatment better than the actual treatment.
In addition, beliefs around how intense the treatment was also had a meaningful role to play.
Professor Kadosh said: “The common wisdom is that the same medical treatment would produce similar results across patients, but our latest study suggests a fascinating twist. While you’d expect uniform improvements in a group of people with depression undergoing the same neurostimulation treatment, outcomes can vary widely.
“What’s truly eye-opening is that this variability could be largely influenced by the participants’ own beliefs about the treatment they’re receiving. In essence, if an individual believes they’re receiving an effective treatment – even when given a placebo – that belief alone might contribute to significant improvements in their condition.”
Across the five studies, researchers found that the effect of patients’ beliefs can differ, from having no impact at all right through to explaining results beyond the treatment itself.
In one study, in which 121 people with depression were treated with different types of Transcranial Magnetic Stimulation (rTMS), the research team found that the participants’ perceptions about whether their treatment was real or fake made a bigger difference than the type of rTMS they received.
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Another study looked at the effect of transcranial random noise stimulation on working memory, but in this case, participants’ beliefs didn’t have any impact on the results.
Co-author Dr Shachar Hochman said: “The concept that a placebo or sham treatment can mimic genuine treatment effects is well-established in science.
“While researchers have closely monitored this phenomenon, it has been typically catalogued separately from the in-depth analyses of the actual treatment outcomes.
“What sets our study apart is that we have brought together these two datasets – subjective beliefs and objective treatment measures. This has the potential to reveal new insights into treatment efficacy.”
Professor Roi Cohen Kadosh added: “Our findings show that there could be real value in recording participants’ subjective beliefs at multiple points in the experiment to better understand their impact and put forward the importance of sharing this data and incorporating it within the research process.
“Recording beliefs might be useful beyond the realms of neurostimulation – we may find similar results in pharmacological studies and more state-of-the-art interventions such as virtual reality, and I would encourage other scientists to use our analytical approach to re-examine results in past interventions and to incorporate it in future ones.”
The study has been published in eLife.