A groundbreaking University of Surrey study has unveiled a critical factor that significantly influences the effectiveness of treatments for depression and ADHD: the patient’s beliefs about their treatment.
This revelation challenges traditional assumptions about the impact of medical interventions for depression and ADHD and highlights the pivotal role of subjective perceptions in treatment outcomes.
The research, encompassing a comprehensive analysis of five distinct studies on neurostimulation treatments, focused on understanding the profound influence of patients’ subjective beliefs.
Covering a spectrum of neurostimulation therapies, including Transcranial Magnetic Stimulation (rTMS) and Transcranial Direct Current Stimulation (tDCS), the studies involved clinical patients undergoing treatment for depression and ADHD, as well as healthy adults.
In four out of five studies, the study demonstrated that patients’ beliefs regarding whether they were receiving real treatment or a placebo explained treatment outcomes.
Astonishingly, in some instances, these subjective beliefs held more sway over treatment results than the actual treatment itself. Moreover, assumptions about the treatment’s intensity emerged as a significant contributor to its efficacy.
Professor Roi Cohen Kadosh of the University of Surrey remarked on the implications of these findings for future research: “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.”
Impacts of subjective beliefs on treatment outcomes
The first study examined 121 participants treated with various forms of rTMS for depression. Surprisingly, participants’ perceptions regarding real or placebo treatment wielded more impact on reducing depression than the actual type of rTMS administered.
In another study involving 52 older adults with late-life depression receiving deep rTMS, the interplay between participants’ beliefs about their treatment and the actual treatment received significantly affected the reduction in depression scores.
Furthermore, a study on 64 adults diagnosed with ADHD using home-based tDCS treatment showcased a dual effect of both participants’ beliefs and the actual treatment in reducing inattention scores.
Dr Shachar Hochman, a co-author on this work from the University of Surrey, 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.”
However, the impact of beliefs was not universal across all studies. In one instance, where varying doses of tDCS were administered to 150 healthy participants for mind wandering, the belief in receiving a more potent dose influenced reported outcomes despite the actual treatment being unrelated.
Interestingly, while beliefs significantly shaped outcomes in most cases, there were exceptions. A study on the impact of transcranial random noise stimulation on working memory revealed that participants’ beliefs did not influence the results.
Advancing treatment for depression and ADHD
The study’s groundbreaking insights shed light on the diverse ways subjective beliefs can interact with neurostimulation treatments, ranging from surpassing the treatment’s effect and interacting with it to exerting no influence at all.
These findings pose critical implications for depression and ADHD treatment strategies, emphasising the necessity of considering patients’ subjective perceptions and beliefs in optimising interventions revolutionising the landscape of medical research and treatment paradigms.
