Impact of a 12-week open-label placebo treatment on headache days in episodic and chronic migraine: a study protocol for a parallel-group, multicentre, randomised controlled trial

Preoperative Anxiolysis and Treatment Expectation (PATE Trial): open-label placebo treatment to reduce preoperative anxiety in female patients undergoing gynecological laparoscopic surgery - study protocol for a bicentric, prospective, randomized-controlled trial

One of the most common concerns of patients undergoing surgery is preoperative anxiety, with a prevalence of up to 48%. The effects of preoperative anxiety continue beyond the preoperative period and are associated with more severe postoperative pain and poorer treatment outcomes. Treatment options for preoperative anxiety are often limited as sedatives cause side effects and their efficacy remains controversial. Placebo research has shown that optimization of positive treatment expectations, as can be achieved through placebo administration and education, has clinically relevant effects on preoperative anxiety, pain and treatment outcomes. As the administration of masked placebos raises ethical questions, clinical studies have increasingly focused on the use of open, non-deceptive placebo administration (open-label placebo, OLP). The use of OLPs to reduce preoperative anxiety and modify clinically relevant postoperative outcomes has not yet been investigated. This bicentric, prospective, randomized-controlled clinical trial (PATE Trial; German Registry for Clinical Studies DRKS00033221), an associated project of the Collaborative Research Center (CRC) 289 "Treatment Expectation", aims to alleviate preoperative anxiety by optimizing positive treatment expectations facilitated by OLP. Furthermore, this study examines a potential enhancement of these effects through aspects of observational learning, operationalized by a positive expectation-enhancing video. In addition, patient's perspective on the self-efficacy and appropriateness of OLPs prior to surgery will be assessed. To achieve these objectives, female patients will be randomized into three groups before undergoing gynecological laparoscopic surgery. One group receives the OLP with a positive rationale conveyed by a study physician. A second group receives the same intervention, OLP administration and rationale provided by a physician, and additionally watches a video on OLP presenting a satisfied patient. A third group receives standard treatment as usual (TAU). Outcome measures will be effects on preoperative anxiety and postoperative experience, particularly visceral and somatic postoperative pain. As the non-deceptive administration of placebos; when indicated; may yield positive outcomes without side effects, and as current treatment of preoperative anxiety is limited, evidence from clinical placebo research has the potential to improve outcomes and patient experience in the surgical setting.

Nocebo effects in visceral pain: concept and design of the experimental randomized-controlled pain study 'NoVis'

The role of psychological factors in the pathophysiology and treatment of chronic visceral pain in disorders of gut-brain interactions (DGBI) is increasingly appreciated. Placebo research has underscored that expectations arising from the psychosocial treatment context and from prior experiences shape treatment responses. However, effects of negative expectations, i.e., nocebo effects, as they are likely crucial elements of DGBI patients' clinical reality, have thus far only rarely been investigated in the context of visceral pain, with untapped potential for improved prevention and treatment. The experimental randomized-controlled pain study "NoVis," carried out within the Collaborative Research Center (CRC) 289 ("Treatment Expectation"), aims to close gaps regarding the generation and persistence of nocebo effects in healthy volunteers. It is designed to elucidate effects of negative expectations in a multiple-threat paradigm with intensity-matched rectal distensions and cutaneous thermal stimuli, allowing to test nocebo effects in the visceral and somatic pain modalities. Negative expectations are experimentally induced by elements of doctor-patient communication (i.e., instruction) and/or by surreptitious amplification of symptom intensity (i.e., experience/learning) within a treatment context. Accordingly, the repeated measures between-subject design contains the between-group factors "treatment instruction" (negative vs. control) and "treatment experience" (negative vs. control), with volunteers randomized into four experimental groups undergoing several pain stimulation phases (repeated factor). This allows to compare the efficacy of instruction vs. experience, and more importantly, their combined effects on the magnitude of negative expectations and their impact on pain responses, which we expect will be greatest for the visceral modality. After a Baseline, short-term effects are assessed during a test phase accomplished on study day 1 (Test-1 Phase). To explore the persistence of effects, a second test phase is accomplished 1 week later (Test-2 Phase). Effects of negative expectations within and across pain modalities are assessed at the subjective and objective levels, with a focus on psychophysiological and neuroendocrine measures related to stress, fear, and anxiety. Since nocebo effects can play a considerable role in the generation, maintenance, or worsening of chronic visceral pain, and may even constitute risk factors for treatment failure, knowledge from experimental nocebo research has potential to improve treatment outcomes in DGBI and other clinical conditions associated with chronic visceral pain.

No long-term effects after a 3-week open-label placebo treatment for chronic low back pain: a 3-year follow-up of a randomized controlled trial

ABSTRACT

Chronic low back pain is prevalent, highly disabling, and a relevant socioeconomic health concern. Although allocated to placebo groups, patients in randomized controlled trials show significant pain relief, pointing to the relevance of placebo effects. Overcoming ethical and legal concerns related to deceptive placebos, recent studies have demonstrated the efficacy of short-term treatments for chronic low back pain with open-label (ie, nondeceptive) placebos. However, data on long-term efficacy of open-label placebos are sparse. Here, we report a 3-year follow-up of our previously published randomized controlled trial demonstrating pain reduction, improvement in disability, and depressive symptoms after a 3-week treatment with open-label placebos. Including records from 89 previously enrolled patients, we investigated changes between the groups with and without previous open-label placebo treatment in pain intensity (primary outcome), disability and mood (secondary outcomes), biopsychosocial factors and lifestyle (exploratory outcomes) from parent baseline to follow-up. Over the 3-year period, there were no differences in any outcome between groups with and without open-label placebo treatment. Therefore, our follow-up data do not support the previously suggested assumption that a 3-week open-label placebo treatment has long-term effects. This study was preregistered on April 14, 2020, in the German Clinical Trials Register (registration number DRKS00021405).