As different as fear and anxiety: Introducing the fear and anxiety model of placebo hypoalgesia and nocebo hyperalgesia.

Research suggests that negative affective states, such as fear and anxiety that accompany placebo treatment may be considered predictors of placebo hypoalgesia and nocebo hyperalgesia. There is also data showing that the likelihood of developing nocebo hyperalgesia is related to the relatively stable tendency to experience these negative emotions. We aimed to summarize the current state-of-the-art in studies and theoretical models on the role of fear and anxiety in placebo hypoalgesia/nocebo hyperalgesia, with a clear differentiation between these emotions.

Social Learning of Placebo Effects in Pain: A Critical Review of the Literature and a Proposed Revised Model.

Relatively recently, in 2009, experimental studies were undertaken to determine the role of social observational learning in forming hypoalgesic, analgesic and hyperalgesic responses to a placebo. The research findings obtained in studies published before 2018 were integrated and formed the basis of the theoretical model of social learning of placebo effects in pain proposed by Bajcar and Bąbel. This model considered the involvement of different types of modeling (ie, behavioral modeling, symbolic modeling, and verbal modeling) in shaping placebo hypoalgesia/analgesia and nocebo hyperalgesia.

Pain memory in children: a systematic review and meta-analysis with a meta-regression.

The aim of this systematic review and meta-analysis was to analyze the accuracy of memory of pain and the variables that may influence it in children with acute, experimental, and chronic pain. We conducted a search in electronic databases from inception to February 11, 2022. Twelve observational studies and 3 randomized controlled studies were included in the study.

Pain Rating is Worth a Thousand Words: Nocebo Hyperalgesia Induced by Verbal Modeling Prevails Over the Effects of Symbolic Modeling and Verbal Suggestion.

This study compares the effectiveness of verbal modeling, symbolic modeling, and verbal suggestion in inducing nocebo hyperalgesia. It is the first study to examine the contribution of stress to observationally induced nocebo hyperalgesia. This study's experimental groups represented various sources of social information: a group of people participating in the study (verbal modeling), a single participant (symbolic modeling), and an experimenter (verbal suggestion).

Placebo Hypoalgesia and Nocebo Hyperalgesia Induced by Observational Learning May Be Difficult to Disentangle in a Laboratory Setting.

Observational learning (OBL) (seeing pain/pain treatment in others) can evoke placebo hypoalgesia and nocebo hyperalgesia. Data that compare these effects and illuminates the role of expectations and empathy are scarce. Healthy participants (n = 105) were randomized to: 1) placebo OBL, 2) nocebo OBL, or 3) no-observation control group.

Learning pain from others: a systematic review and meta-analysis of studies on placebo hypoalgesia and nocebo hyperalgesia induced by observational learning.

Observing someone experience pain relief or exacerbation after an intervention may induce placebo hypoalgesia or nocebo hyperalgesia. Understanding the factors that contribute to these effects could help in the development of strategies for optimizing treatment of chronic pain conditions. We systematically reviewed and meta-analyzed the literature on placebo hypoalgesia and nocebo hyperalgesia induced by observational learning (OL).

From past pain to future pain through the pain of others: Information about other people's pain ratings can alleviate our subsequent pain.

Background: Previous studies have shown that pain memories have a profound impact on subsequent pain experiences. This study investigated whether pain ratings derived from other people can modify an individual's memory of past pain. This study also examined whether pain memory modified by others' pain ratings determines subsequent pain experiences.

Development and cross-national investigation of a model explaining participation in WHO-recommended and placebo behaviours to prevent COVID-19 infection.

To protect themselves from COVID-19, people follow the recommendations of the authorities, but they also resort to placebos. To stop the virus, it is important to understand the factors underlying both types of preventive behaviour. This study examined whether our model (developed based on the Health Belief Model and the Transactional Model of Stress) can explain participation in WHO-recommended and placebo actions during the pandemic.

The Effects of Pain Expectancy and Desire for Pain Relief on the Memory of Pain in Half Trail Marathon Runners.

Purpose: It has been shown that the memory of pain induced by running might be underestimated. Our previous study showed the contribution of emotional factors to this process. This study aimed to investigate the cognitive factors that might influence the memory of this type of pain, ie expectancy of pain intensity, expectancy of pain unpleasantness, and desire for pain relief.

The Lighter Side of Pain: Do Positive Affective States Predict Memory of Pain Induced by Running a Marathon?

Background: Memory and in turn, memory of pain is a reconstructive process. This study considers the relationship between time, memory, affective states, and pain induced by running a marathon by investigating the influence of these factors on a participant's memory of pain experienced after a marathon. The following two hypotheses were formulated: 1) participants' recalled-pain of marathon experience is underestimated; and 2) the underestimation of recalled pain would be greater for participants experiencing higher positive affect.

When one suffers less, all suffer less: Individual pain ratings are more effective than group ratings in producing placebo hypoalgesia.

Background: Placebo hypoalgesia can be induced by observing a person (model) whose pain relief is the result of the use of an inert substance or procedure. This study examined whether verbal modelling, that is, showing pain ratings provided by other people, is sufficient to induce placebo hypoalgesia.

Methods: Participants from the experimental groups were acquainted with pain ratings (presented on VASs) derived from a single person (groups 1 and 3) or a group of people (groups 2 and 4) that were allegedly subjected to the same painful procedure.

Order does matter: the combined effects of classical conditioning and verbal suggestions on placebo hypoalgesia and nocebo hyperalgesia.

In most experimental studies in which verbal suggestion and classical conditioning are implemented together to induce placebo effects, the former precedes the latter. In naturally occurring situations, however, the information concerning pain does not always precede but often follows the pain experience. Moreover, this information is not always congruent with experience.

One of us or one of them? The effects of the model's and observer's characteristics on placebo analgesia induced by observational learning.

Previous studies have proved that observational learning can induce placebo analgesia, but the factors that influence observationally induced placebo analgesia have not yet been extensively examined. The primary goal of this study was to investigate the effect of information about the role that the observed person (model) plays in the experiment on the magnitude of the observationally induced placebo effect. This study also examined the contribution of the observer's empathy, conformity and fear of pain to the placebo analgesia induced by observational learning.

Nocebo hyperalgesia can be induced by classical conditioning without involvement of expectancy.

Influential theoretical accounts take the position that classical conditioning can induce placebo effects through conscious expectancies. In the current study two different conditioning procedures (hidden and open) were used to separate expectancy from conditioning in order to reveal the role of expectancy in the formation of nocebo hyperalgesia. Eighty-seven healthy females were randomly assigned to three groups (hidden conditioning, open conditioning, and control).

Memory of pain in adults: a protocol for systematic review and meta-analysis.

Background: The way pain is remembered and reported can affect medical decisions taken by patients and health-care professionals. Memory of pain has been investigated extensively for the past few decades; however, the results of previous studies are highly variable, indicating that the recollection of pain can be accurate, overestimated or underestimated. It is therefore difficult to conclude how well pain is remembered.

To Experience or to Be Informed? Classical Conditioning Induces Nocebo Hyperalgesia even when Placebo Analgesia Is Verbally Suggested-Results of a Preliminary Study.

Objective: To investigate whether direct experience (i.e., classical conditioning) or verbal suggestion is more important in inducing nocebo hyperalgesia, five groups (total sample size, N = 99) were studied: conditioning, congruent conditioning, incongruent conditioning, verbal suggestion, and control.

Rewarded placebo analgesia: A new mechanism of placebo effects based on operant conditioning.

Background: Placebo analgesia is explained by two learning processes: classical conditioning and observational learning. A third learning process, operant conditioning, has not previously been investigated as a mechanism of placebo effects. We aimed to induce placebo analgesia by operant conditioning.

Placebo Groups in Research on the Effectiveness of ABA Therapeutic Techniques.

Behavior analysts have shown that a single-subject experimental design (SSED) is a useful tool for identifying the effectiveness of specific therapeutic techniques, whereas researchers outside applied behavior analysis (ABA) maintain that randomized placebo-controlled trials (RPCT) provide the most definite test of efficacy. In this paper the possible benefits that could result from supporting SSED studies by placebo control groups are discussed. However, the use of placebo groups in psychotherapy research arouses considerable controversy and many researchers argue against it.

How Does Observational Learning Produce Placebo Effects? A Model Integrating Research Findings.

There is a growing body of evidence proving that observational learning, in addition to classical conditioning and verbal suggestions, may induce both placebo analgesia and nocebo hyperalgesia. However, much less is known about the mechanisms and factors influencing placebo effects induced by observational learning. The paper critically reviews the research findings in the field in the context of Bandura's social learning theory.

How Classical Conditioning Shapes Placebo Analgesia: Hidden versus Open Conditioning.

Objective: To investigate the influence of expectancy of pain intensity, fear of pain (trait), and fear (state) on the effectiveness of hidden and open conditioning to produce placebo analgesia.

Methods: A total of 90 healthy female volunteers were randomly assigned to three groups (hidden conditioning, open conditioning, and control) that received electrical stimuli preceded by either orange or blue lights. One color was paired with painful stimuli (control stimuli) and the other color was paired with nonpainful stimuli (conditioned stimuli) in both the hidden and open conditioning groups.

Classical conditioning without verbal suggestions elicits placebo analgesia and nocebo hyperalgesia.

The aim of this study was to examine the relationships among classical conditioning, expectancy, and fear in placebo analgesia and nocebo hyperalgesia. A total of 42 healthy volunteers were randomly assigned to three groups: placebo, nocebo, and control. They received 96 electrical stimuli, preceded by either orange or blue lights.