Effects of open and hidden administration of treatment-related information; a multi-experiment study.

Background: Two experiments (E1 and E2;  = 44 and  = 52, respectively) investigated the effect of positive (PI) and neutral information (NI) about a dental procedure, and if the delivery of the information by the treatment team (open administration) or unbeknownst to the treatment team (hidden administration), affected pain.

Methods: Using a mixed design, patients undergoing drilling in a molar were randomized to the NI or PI groups. Before, during, and after treatment, patients reported their pain and stress levels.

The Effect of Singular Nonverbal Behaviours of Experimenters on Pain Reports.

Introduction: Studies suggest facial expressions of caregivers may be important in placebo effects; however, this has not been systematically tested. This experiment investigated the effects of caregivers' singular positive nonverbal behaviours (NBs) on pain reports.

Methods: Fifty-one males and 53 females (total of 104) participants were randomized to four groups that were displayed positive facial expressions, tone of voice, body movement, or neutral NBs of videotaped experimenters.

Systematic manipulation of experimenters' non-verbal behaviors for the investigation of pain reports and placebo effects.

Objective: Non-verbal behaviors (NBs) of caregivers affect pain reports and placebo effects. However, little experimental research has systematically examined the caregivers' NBs. This study protocol and preparatory study report a systematic manipulation of experimenters' NBs to investigate pain report and placebo effects.

A global meta-analysis of depression, anxiety, and stress before and during COVID-19.

Objective: This meta-analysis compared negative emotions (NEs) as depression, anxiety, and stress, from before the pandemic to during the pandemic.

Method: A total of 59 studies (19 before, 37 during-pandemic, and 3 that included both) using the Depression, Anxiety and Stress Scale (DASS) were included. A random effects model estimated the means of NEs before and during the pandemic.

Placebo Effects on Stress, but Not on Pain Reports. A Multi-Experiment Study.

Background: Contextual factors, such as participant/experimenter sex may moderate the placebo effects. We tested whether the participant and experimenter sex modulated placebo effects on experimentally induced pain and associated stress.

Objective: To investigate if (i) participant sex and (ii) experimenter sex influence placebo analgesia and subjective and physiological stress in two experiments employing a within-subjects and a mixed design, respectively.

Experiencing COVID-19 symptoms without the disease: The role of nocebo in reporting of symptoms.

Background: A nocebo effect occurs when inactive factors lead to worsening of symptoms or reduce treatment outcomes. Believing that one is or has been infected with COVID-19 may act as a nocebo. However, not much is known about potential nocebo effects associated with the reporting of COVID-19 symptoms.

What Psychological Factors Make Individuals Believe They Are Infected by Coronavirus 2019?

We previously showed, by means of an online-based survey, that the belief of being infected by coronavirus disease 2019 (COVID-19) acted as a nocebo and predicted higher perception of symptoms similar to COVID-19 symptoms. However, there is little known about the psychological mechanisms that give rise to beliefs such as certainty of being infected by COVID-19, and this was investigated in the present study. Using the same data from the previous online survey with the same research team, we further investigated whether certainty of being infected by COVID-19 is associated with age, sex, health anxiety, and/or personality traits.

Placebo Analgesia, Nocebo Hyperalgesia, and the Cardiovascular System: A Qualitative Systematic Review.

Placebo/nocebo effects involve the autonomic nervous system, including cardiac activity, but studies have reported inconsistent findings on how cardiac activity is modulated following a placebo/nocebo effect. However, no systematic review has been conducted to provide a clear picture of cardiac placebo responses. The main goal of the present study is to review the effects of placebo analgesia and nocebo hyperalgesia on cardiac activity as measured by blood pressure, heart rate, and heart rate variability.

A Qualitative Systematic Review of Effects of Provider Characteristics and Nonverbal Behavior on Pain, and Placebo and Nocebo Effects.

Previous research has indicated that the sex, status, and nonverbal behaviors of experimenters or clinicians can contribute to reported pain, and placebo and nocebo effects in patients or research participants. However, no systematic review has been published. The aim of this study was to investigate the effects of experimenter/clinician characteristics and nonverbal behavior on pain, placebo, and nocebo effects.

The Relationship of Parental Pain Catastrophizing with Parents Reports of Children's Anxiety, Depression, and Headache Severity.

Objective: Parental pain catastrophizing is a construct recognized to have a significant impact on experience of pain in both children and parents. This research aimed to investigate the probable relationship of parental pain catastrophizing with the parent's reports of children's anxiety, depression and headache severity amongst Iranian parents of children with chronic or recurrent headache.

Materials & Methods: This study was conducted in 2015-16, in two pediatric neurological centers located in Tehran, Iran; with a convenience sampling method and 212 parents (120 mothers and 92 fathers) of 132 children with a chronic or recurrent headache (migraine and tension-type).