How do placebo effects and patient-clinician relationships influence behaviors and clinical outcomes?

Placebo effects modulate clinical outcomes, result from the patient, proxy, and provider’s expectancies, and depart from confounding factors such as regression to the mean, spontaneous remission, and symptoms’ fluctuations. From a psychological perspective, placebo effects have been attributed to verbal suggestions and anticipation of therapeutic benefits, previous therapeutic experiences, observation and social learning, contextual cues, and interpersonal patient–clinician interactions. This theme issue covers both theoretical and original research articles exploring how often overlooked aspects of patient’s medical encounters and experiences can influence health outcomes through the placebo and nocebo effects in pain medicine. Namely, the 5 articles and 3 reviews included in this special issue illustrate how a variety of factors, ranging from perception of competence and warmth before a surgical procedure to psychological changes occurring as a result of treatment framing, alter pain experience and placebo effects. Other factors discussed include the role of expectations, desire for pain relief, and anxiety in pain-relieving intervention such as medial branch radiofrequency neurotomy low back pain patients, an online method of placebo manipulation, andoperant conditioningwith avoidancemovements. The reviews describe the need for encouraging education about contextual and placeboeffects in nursing, strategies tominimize noceboeffects, and relevance of placebo effects for central nervous system (CNS) disorders. Together, this collection of innovative studies provides a diverse snapshot of the clinical relevance of placebo and nocebo effects and, most importantly, how health practitioners might harness them to improve health outcomes. Patient–clinician interactions can influence patients’ perception of health pain outcomes through placebo and nocebo effects. However, it remained unknown how the patient’s perception of warmth and competence of the clinician can affect clinical pain outcomes. Patients’ feelings of surgeons’ warmth and competence assessed immediately before wisdom tooth extraction surgery influenced the patients’ postsurgical experiences of trust and acute pain; when patients perceived the surgeon as highly competent, but not warm, they experienced higher trust and lower pain during surgery. Thus, a key aspect of the patient–clinician interactions is competence of health practitioners while interacting with their patients and the impression they create. Another important feature of the clinical encounter is how treatments are presented to patients. Disclosure and framing effects can eventually change treatment efficacy expectations, pain experience expectations, anxiety, positive and negative affect, and autonomic responses. To this end, Geers designed a study in which a standard analgesic message, an analgesic treatment with side-effect message, and a double-blind analgesic message alongwith a control treatmentmessageweredelivered. They found that treatment-specific expectations changedas a result of theway the information is framed compared with the other conditions and the control message. The fact that treatment messages can influence participants’ expectations of treatment efficacy can be relevant for daily clinical practice. Moreover, preintervention information acquired through websites is ubiquitously present in clinical settings. Investigating the impact of online delivery of information can have clinically relevant applications and can contribute to the development and improvement of both therapeutic strategies and tools to help patients alleviate their pain. In this issue, Pontén explored the occurrence of placebo effects when participants received the information about the nature of the study and related goals through online communication. Healthy participants were randomized to either empathetic or neutral online communication before completing an in-person placebo analgesia experiment. The online communication was designed to elicit significant placebo effects as compared to the control group, inwhich a shamanalgesic device,without any previous communication was used. Significant placebo effects were induced by the online video clip as compared to the sham analgesic device without any previous communication that did not Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article. a Department of Pain and Translational Symptom Science, School of Nursing, University of Maryland, Baltimore, Baltimore, MD, USA, b Departments of Anesthesiology and Psychiatry, School of Medicine, University of Maryland, Baltimore, Baltimore, MD, USA, c Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD, USA