Context matters: the psychoneurobiological determinants of placebo, nocebo and context-related effects in physiotherapy

Abstract

Background: Placebo and nocebo effects embody psychoneurobiological phenomena where behavioural, neurophysiological, perceptive and cognitive changes occur during the therapeutic encounter in the healthcare context. Placebo effects are produced by a positive healthcare context; while nocebo effects are consequences of negative healthcare context. Historically, placebo, nocebo and context-related effects were considered as confounding elements for clinicians and researchers. In the last two decades this attitude started to change, and the understanding of the value of these effects has increased. Despite the growing interest, the knowledge and the awareness of using the healthcare context to trigger placebo and nocebo effects is currently limited and heterogeneous among physiotherapists, reducing their translational value in the physiotherapy field. Objectives: To introduce the placebo, nocebo and context-related effects by: (1) presenting their psychological models; (2) describing their neurophysiological mechanisms; (3) underlining their impact for the physiotherapy profession; and (4) tracing lines for future researches. Conclusion: Several psychological mechanisms are involved in placebo, nocebo and context-related effects; including expectation, learning processes (classical conditioning and observational learning), reinforced expectations, mindset and personality traits. The neurophysiological mechanisms mainly include the endogenous opioid, the endocannabinoid and the dopaminergic systems. Neuroimaging studies have identified different brain regions involved such as the dorsolateral prefrontal cortex, the rostral anterior cingulate cortex, the periaqueductal gray and the dorsal horn of spine. From a clinical perspective, the manipulation of the healthcare context with the best evidence-based therapy represents an opportunity to trigger placebo effects and to avoid nocebo effects respecting the ethical code of conduct. From a managerial perspective, stakeholders, organizations and governments should encourage the assessment of the healthcare context aimed to improve the quality of physiotherapy services. From an educational perspective, placebo and nocebo effects are professional topics that should be integrated in the university program of health and medical professions. From a research perspective, the control of placebo, nocebo and context-related effects offers to the scientific community the chance to better measure the impact of physiotherapy on different outcomes and in different conditions through primary studies.

Understanding Contextual Factors Effects and Their Implications for Italian Physiotherapists: Findings from a National Cross-Sectional Study

“…Few considered them to be a specific therapeutic tool capable of influencing patients' clinical outcomes [5,9,11]. This point of view may be related to limited knowledge regarding the neurophysiological mechanisms behind the therapeutic effects of CFs [1,21,22]. Several participants stated having learned about CFs during a 2nd cycle degree class.…”

Pain and the field of affordances: an enactive approach to acute and chronic pain

“…Concerned subjects might withdraw more and more while this social isolation in turn prevents any positive effects of safety signaling in socio-cultural contexts. Further, various physiological factors shape the direction and magnitude of placebo or nocebo effects (Rossettini et al, 2020). There is evidence that this involves various endocrine systems and brain networks that partly determine the effects of socio-cultural factors while being in turn continuously shaped by individual experiences and learning processes.…”

‘Don't focus on the finger, look at the moon’ - The importance of contextual factors for clinical practice and research

“…Although the importance of CFs have been recognised by various healthcare professions (e.g. physiotherapy, nursing) [10,11] and how they represent a valuable and desired element of the therapeutic encounter [12], they are still largely unexplored within osteopathy. Research and theoretical work could help provide opportunities for osteopaths to recognise and optimise CFs in the context of their evidence-informed person-centred approaches.…”

“…In osteopathy education, students are taught the specific/biological factors that are believed to influence and be responsible for the effects of their specific therapeutic interventions, and these are emphasised in their learning (e. g. soft tissue stretching or spinal manipulation leading to changes in blood flow, neural pathways activation). Given this focus, there is likely underdevelopment of theory and evidence pertinent to osteopathic care on the management of CFs, and how they may enhance placebo and avoid nocebo effects [10]. Therefore, osteopaths may not be fully aware of the role tha CFs have in creating a therapeutic environment for their patient, and it is not known how CFs feature in their clinical reasoning or education.…”

“…Secondly, controlling CFs in research. For many years, researchers trying to test the effectiveness of treatment have sought to remove or neutralise CFs to 'get' to the core of the 'real' therapeutic effects [10]. On the one hand, this de-contextualisation through methodological rigor and objectivity has allowed researchers to produce robust randomised-controlled trials with sufficient internal validity necessary for highlighting the specificity of our interventions.…”