Summary: A groundbreaking study has brought to light the significant impact of patients’ beliefs on the effectiveness of neurostimulation treatments for conditions like depression and ADHD. The research team found that patients’ perceptions of receiving either real or placebo treatments often had more of an impact on outcomes than the treatments themselves.
Results showed that this effect varied across studies, where patient beliefs sometimes wholly explained the results, interacted with the treatment, or had no influence at all.
These findings emphasize the importance of considering and documenting patients’ beliefs in clinical research, indicating it could be a critical element in the efficacy of treatments across various medical fields.
Key Facts:
- Patients’ beliefs about their treatment played a crucial role in the outcomes of four out of five neurostimulation studies.
- The impact of belief sometimes outweighed the actual treatment itself.
- The study proposes that incorporating patient beliefs into the research process could uncover fresh insights into treatment effectiveness.
Source: University of Surrey
Valuing the power of patients’ beliefs in their treatment experience
A group of psychologists, led by Professor Roi Cohen Kadosh from the University of Surrey, meticulously analyzed five independent studies covering various types of neurostimulation treatments in order to comprehend the role of patients’ subjective beliefs. These studies included clinical patients receiving treatment for ADHD and depression, alongside healthy adults.
The study revealed that in four out of five studies, patients’ beliefs about whether they were undergoing real or placebo treatments explained the outcomes. On some occasions, the participants’ beliefs actually accounted for treatment outcomes better than the actual treatment itself. Furthermore, assumptions about the efficacy of the treatment also played a substantial role.
Professor Roi Cohen Kadosh from the University of Surrey commented on the results: “Conventionally, it’s believed that the same medical treatment would yield similar results across patients, but our latest study suggests an intriguing twist. While uniform improvements are anticipated in a group of individuals with depression undergoing the same neurostimulation treatment, the outcomes can actually fluctuate significantly.
“What’s particularly eye-opening is that this variability could be heavily influenced by the participants’ own beliefs about the treatment they’re receiving. Essentially, if an individual believes they’re receiving an effective treatment—regardless of whether they are receiving a placebo—this belief alone could contribute to notable improvements in their condition.”
The first study analyzed involved 121 participants being treated with various forms of Transcranial Magnetic Stimulation (rTMS) for depression. The findings showed that the perceptions of receiving real or placebo treatment by participants were more influential than the type of rTMS in reducing depression.
The second study included 52 older individuals with late-life depression who received either a genuine or placebo of deep rTMS. Researchers at Surrey discovered that the effect of treating depression depended on the combination of participants’ perceptions about receiving real or placebo treatment and the actual treatment received.
In the third dataset, scientists explored the impact of home-based Transcranial Direct Current Stimulation (tDCS) treatment on 64 adults diagnosed with ADHD. Towards the end of the study, the participants’ beliefs about the treatment they thought they had received were also documented. Unlike the first two studies, both the participants’ beliefs and the actual treatment had a dual effect on reducing inattention scores.
In the fourth study, 150 healthy participants received varying doses of tDCS for mind wandering. Interestingly, those who believed they received a more potent dose reported increased mind wandering, even if the actual treatment didn’t play a role. Furthermore, the fifth study examined the influence of transcranial random noise stimulation on working memory, showing that participants’ beliefs did not affect the results, highlighting the varying influence of beliefs in brain stimulation research.
Thus, Roi Cohen Kadosh and his team demonstrate how subjective beliefs can differ in their effect on research, from fully explaining results beyond the actual treatment, to interacting with the treatment, to not having any influence at all.
Dr Shachar Hochman, co-author from the University of Surrey, remarked: “The notion that a placebo or sham treatment can mimic genuine treatment effects is well-established in science. Although researchers have closely followed this phenomenon, it has typically been cataloged independently from detailed analyses of actual treatment outcomes.
“What sets our study apart is that we have combined these two datasets—subjective beliefs and objective treatment measures. This could potentially unveil new insights into treatment effectiveness.”
Professor Roi Cohen Kadosh added: “Our findings suggest that there could be significant value in recording participants’ subjective beliefs at multiple points during the experiment to better understand their impact. This highlights the importance of sharing this data and incorporating it within the research process.
“Recording beliefs might be insightful beyond neurostimulation. We could observe similar outcomes in pharmacological studies and state-of-the-art interventions such as virtual reality, and I urge other scientists to apply our approach to review past intervention results and integrate it in future studies.”
About this psychology research news
Author: Dalitso Njolinjo
Source: University of Surrey
Contact: Dalitso Njolinjo – University of Surrey
Image: The image is credited to Neuroscience News
Original Research: Open access.
“The Importance of Individual Beliefs in Assessing Treatment Efficacy: Insights from Neurostimulation Studies” by Roi Cohen Kadosh et al. eLife
Abstract
The Importance of Individual Beliefs in Assessing Treatment Efficacy: Insights from Neurostimulation Studies
In recent years, there has been debate about the effectiveness of treatments from different fields, such as neurostimulation, neurofeedback, brain training, and pharmacotherapy.
This debate has been fueled by contradictory and nuanced experimental findings. Notably, the effectiveness of a given treatment is commonly evaluated by comparing the effect of the active treatment versus the placebo on human health and/or behavior. However, this approach neglects the individual’s subjective experience of the type of treatment s/he received in establishing treatment efficacy.
Here, we show that individual differences in subjective treatment—the thought of receiving the active or placebo condition during an experiment—can explain variability in outcomes better than the actual treatment.
We analyzed four independent datasets (N=387 participants), including clinical patients and healthy adults from different age groups who were exposed to different neurostimulation treatments (transcranial magnetic stimulation: Study 1 & 2; transcranial direct current stimulation: Study 3 & 4).
Our findings consistently show that the inclusion of subjective treatment provides a better model fit than objective treatment alone—the condition to which participants are assigned in the experiment. These results demonstrate the significant contribution of subjective experience in explaining the variability of clinical, cognitive, and behavioral outcomes.
Based on these findings, we advocate for existing and future studies in clinical and non-clinical research to start accounting for participants’ subjective beliefs when assessing the efficacy of treatments. This approach will be crucial in providing a more accurate estimation of the treatment effect and its source, allowing the development of effective and reproducible interventions.
