Placebo Condition Research Articles

Acute effects of caffeine supplementation on kinematics and kinetics of sprinting.

We investigated the acute effects of caffeine supplementation (6 mg･kg-1 ) on 60-m sprint performance and underlying components with a step-to-step ground reaction force measurement in 13 male sprinters. After the first round sprint as a control, caffeine supplementation-induced improvement in 60-m sprint times (7.811 s at the first versus 7.648 s at the second round, 2.05%) were greater compared with the placebo condition (7.769 s at the first versus 7.768 s at the second round, 0.02%). Using average values for every four steps, in the caffeine condition, higher running speed (all six step groups), higher step frequency (5th-16th and 21st-24th step groups), shorter support time (all the step groups except for 13th-16th step) and shorter braking time (9th-24th step groups) were found. Regarding ground reaction forces variables, greater braking mean force (13th-19th step group), propulsive mean force (1st-12th and 17th-20th step groups), and effective vertical mean force (9th-12th step group) were found in the caffeine condition. For the block clearance phase at the sprint start, push-off and reaction times did not change, while higher total anteroposterior mean force, average horizontal external power, and ratio of force were found in the caffeine condition. These results indicate that, compared with placebo, acute caffeine supplementation improved sprint performance regardless of sprint sections during the entire acceleration phase from the start through increases in step frequency with decreases in support time. Moreover, acute caffeine supplementation promoted increases in the propulsive mean force, resulting in the improvement of sprint performance.

Low blood concentration of alcohol enhances activity related to stopping failure in the right inferior frontal cortex.

This study investigated the effects of low doses of alcohol, which are acceptable for driving a car, on inhibitory control and neural processing using the stop-signal task (SST) in 17 healthy right-handed social drinkers. The study employed simultaneous functional magnetic resonance imaging and electromyography (EMG) recordings to assess behavioral and neural responses under conditions of low-dose alcohol (breath-alcohol concentration of 0.15mg/L) and placebo. The results demonstrated that even a small amount of alcohol consumption prolonged Go reaction times in the SST and modified stopping behavior, as evidenced by a decrease in the frequency and magnitude of partial response EMG that did not result in button pressing during successful inhibitory control. Furthermore, alcohol intake enhanced neural activity during failed inhibitory responses in the right inferior frontal cortex, suggesting its potential role in behavioral adaptation following stop-signal failure. These findings suggest that even low levels of alcohol consumption within legal driving limits can greatly impact both the cognitive performance and brain activity involved in inhibiting responses. This research provides important evidence on the neurobehavioral effects of low-dose alcohol consumption, with implications for understanding the biological basis of impaired motor control and decision-making and potentially informing legal guidelines on alcohol consumption.

Drinking alcohol appears to have no impact on self-perceptions of morality, aggressiveness, or intelligence.

People generally perceive themselves as moral but does this tendency change after alcohol consumption? In the current research, we tested whether alcoholic intoxication affects self-assessments of morality (i.e., the self-importance of moral identity and the moral self-concept), and we also tested self-assessment of aggressiveness and intelligence. We conducted a preregistered laboratory experiment with participants divided into three groups: alcohol intoxication (n = 106), placebo (n = 114), and control condition (n = 109). We did not detect statistically significant differences in self-assessments across conditions. These data are consistent with the conclusion that self-assessments of morality, aggressiveness, and intelligence may be too stable to be affected by the momentary changes in self-perception caused by alcoholic intoxication. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Evaluating an EEG-based tool for assessing acute clinical and cognitive changes in adult outpatients with MDD treated with open-label, flexible-dose vortioxetine: A pilot study

BackgroundIdentifying neurological biomarkers to aid with diagnoses and treatment effect evaluation of mood and cognitive symptoms in major depressive disorder (MDD) is an unmet need. This study explores the Brain Network Analytics (BNA) tool, which provides information on cortical patterns compared to a healthy normative group, for improving MDD management. MethodsBNA was used to extract event-related potentials (ERPs) from high-density EEG, and its clinical utility to assess the effects of vortioxetine on depression and cognition was evaluated. Twenty-five MDD subjects (20–65 years old) with cognitive dysfunction underwent an 8-week open-label treatment using vortioxetine. ERP data, generated during cognitive tasks, were collected at pre-treatment, two weeks and eight weeks into treatment. Correlations with MDD symptoms and cognitive functioning were investigated. Exploratory analyses assessed the differences in baseline and endpoint ERP characteristics between MDD subjects and matched controls (N = 41). ResultsCompared to controls, MDD subjects exhibited increased baseline latencies of P200 and P3b ERP components, which normalized at treatment endpoint. P200 and P300 in the MDD group were correlated with clinical assessments, and indicated a pro-cognitive effect of vortioxetine independent of its antidepressant effect. LimitationsThis study was limited by a small sample size and lack of a placebo condition. ConclusionsOur results suggest that the application of BNA can potentially support MDD diagnosis and monitor treatment efficacy across various symptom and functional domains. Further studies are warranted to explore the role of BNA in clinical research and practice.

Effects of combined interventions to optimize performance during high‐intensity exercise in trained individuals

AbstractDifferent interventions can independently improve athletic performance via different central or peripheral mechanisms, but little is known about their potential combination. We tested the effects of seven combined interventions (enhanced recovery package [ERP]) on performance during intermittent high‐intensity cycling compared with placebo. Sixteen trained men (maximal power output: 5.0 ± 0.5 W･kg−1) completed six 30‐s cycling sprints with 3‐min breaks in‐between under ERP, placebo, and control conditions. The ERP combined neck cooling, carbohydrate and caffeine mouth rinsing, carbohydrate and water ingestion, hyperventilation, hyperoxia, and potentiation maneuvers. Power output, heart rate, blood lactate concentration, rate of perceived exertion, and gas exchange were compared between the ERP and placebo conditions. Mean power output was higher during ERP compared with placebo (570 ± 74 W vs. 560 ± 71 W, p < 0.001, dz = 1.15). Heart rate was higher (+3 ± 4 bpm, p = 0.012) during ERP, as was breathing frequency (+2.4 ± 4.0 breaths･min−1, p = 0.028) and respiratory exchange ratio (+0.12 ± 0.06, p < 0.001). Oxygen uptake was 80 ± 109 mL･min−1 lower (p = 0.013) for ERP. No differences were found with regards to the rate of perceived exertion or blood lactate concentration. Performance gains with ERP were small in magnitude but consistent across individuals. The ERP might have prevented a loss of aerobic efficiency or increased reliance on anaerobic energy. Testing combined interventions might increase the chances to see beyond daily variability in practice.

Intrasession Caffeine Intake and Cycling Performance After Accumulated Work: A Field-Based Study.

Preexercise caffeine intake has proven to exert ergogenic effects on cycling performance. However, whether these benefits are also observed under fatigue conditions remains largely unexplored. We aimed to assess the effect of caffeine ingested during prolonged cycling on subsequent time-trial performance in trained cyclists. The study followed a triple-blinded, randomized, placebo-controlled cross-over design. Eleven well-trained junior cyclists (17 ± 1years) performed a field-based 8-min time trial under "fresh" conditions (i.e.,after their usual warm-up) or after two work-matched steady-state cycling sessions (total energy expenditure∼20kJ/kg and ∼100min duration). During the latter sessions, participants consumed caffeine (3mg/kg) or a placebo ∼60min before the time trial. We assessed power output, heart rate, and rating of perceived exertion during the time trial and mood state (Brunel Mood Scale) before and after each session. No significant condition effect was found for the mean power output attained during the time trial (365 ± 25, 369 ± 31, and 364 32W for "fresh," caffeine, and placebo condition, respectively; p = .669). Similar results were found for the mean heart rate (p = .100) and rating of perceived exertion (p = 1.000) during the time trial and for the different mood domains (all p > .1). Caffeine intake during prolonged exercise seems to exert no ergogenic effects on subsequent time-trial performance in junior cyclists. Future studies should determine whether significant effects can be found with larger caffeine doses or after greater fatigue levels.

세계 내에서 관계하는 몸으로 바라본 위약효과

Placebo effects are intriguing phenomena in which beneficial healing effects happen despite the administration of a placebo, which has no active substances or involves inert procedures. Multi-dimensional characteristics have been involved in placebo effects, exhibiting various and non-specific modalities. The two most representative well-known explanatory models on placebo effects, expectancy and conditioning theories, which have perspectives rooted in Cartesian dualism that separate mind and body, show inherent limitations and problems in sufficiently explaining placebo effects. In order to elucidate placebo effects which shows non-separative, connective and relating aspects, new models capable of embracing and explaining such aspects are required. This study attempted to examine how placebo effects could happen in our bodies by means of studies based upon phenomenology and enactivism as models to account for the connective, combining, and interactive relations between various dimensions. This study elucidates the mechanisms of placebo effects using the phenomenological and various enactive concepts. At the heart of connections and relations between several heterogenous dimensions, relating bodies as embodied beings are closely involved in the dynamic interactions with our mind and environments. Our bodies where health, illness, and healing processes through medical practices including placebo effects take place could be considered as the very relation itself in which our internal and external worlds encounter and interact. This study suggests that continual establishment and verification of new theories concerning these relations, which are manifested in placebo effect, are required to deal persuasively with the topic, and the need for appropriate utilization of the relational aspects of placebo effects.

Acute effect of hydrogen-rich water on physical, perceptual and cardiac responses during aerobic and anaerobic exercises: a randomized, placebo-controlled, double-blinded cross-over trial.

Molecular hydrogen (H2 gas) dissolved in water to produce Hydrogen-Rich Water. Hydrogen-Rich Water (HRW) is considered as ergogenic aid in different exercise modes. However, acute pre-exercise HRW ingestion effect is unclear regarding athlete performance. This study aimed at investigating acute effect of HRW ingestion on aerobic and anaerobic exercise performance. Twenty-two male amateur middle-distance runners volunteered to participate in this study. In a randomized, double-blind study design, all players ingested 500mL of HRW or placebo (PLA) supplement 30min before the start of the tests. Over 4 days, maximal aerobic speed of Vameval test (MAS), time to exhaustion at MAS (Tlim), squat jump (SJ), counter-movement jump (CMJ) and five jump test (5JT) were evaluated. Also, rate of perceived exertion (RPE) and peak heart rate (HRpeak) were measured during the aerobic tests. For Vameval test, HRW ingestion improved MAS, HRpeak and RPE compared with the placebo condition. For Tlim test, HRW ingestion demonstrated improvements in time to exhaustion, RPE and HRpeak. However, no significant change was observed between HW and placebo conditions in SJ, CMJ, 5JT. 500mL of HRW can significantly improve HRpeak, time to exhaustion, RPE, with no significant effect on MAS, jumping performance in amateur endurance athletes.

Effect of intra‐nasal insulin therapy on food intake among African American adults: the FIINAAL study

AbstractBackgroundIntranasal insulin is a promising treatment for cognitive decline in Alzheimer’s Disease (AD) and mild cognitive impairment (MCI). However, intranasal insulin has been shown to promote weight loss, leading to concerns about decreased appetite, decreased food intake, and unintentional weight loss as negative side effects among metabolic and ingestive behavior effects of intranasal insulin sprays among AD and MCI patients. But, side effects related to food intake and appetite are not well studied, particularly among African American adults who are under‐represented in AD research.Method39 middle‐aged, cognitively normal, community‐dwelling African American adults (Table 1) were enrolled in the Food Intake and Intranasal Insulin in African American Adults (FIINAAL) study assessing effects of intranasal insulin on acute food intake and appetite ratings. This double‐blind, placebo‐controlled, randomized crossover study compared a single intranasal dose of 10 IUs of Novologã insulin, delivered with the Kurveã device, to an intranasal placebo. Participants ate a eucaloric, macronutrient‐balanced lead‐in diet for three days prior to each dose. The dose was administered in the morning following an overnight fast. An ad libitum test lunch followed the dose and participants rated their appetite immediately before and after each dose, and after the meal. Mixed effects linear model t‐tests were used to compare differences in food intake and appetite ratings between insulin and placebo conditions.ResultThere were no significant differences in test lunch energy (calories) or macronutrient intake between insulin and placebo conditions. However, fullness ratings increased significantly more after receiving a dose of insulin than after a dose of placebo (Figure 1). In addition, desire to consume sweet and fatty foods decreased significantly more after insulin than after placebo (Figure 2).ConclusionIn middle aged African American adults, acute intranasal insulin administration was associated with a reduced desire to eat palatable foods and with increased feelings of fullness, but not with reduced food intake at a test meal. Because reduced appetite appears to be an acute side effect of intranasal insulin administration, future work should study whether chronic intranasal insulin administration results in reduced appetite and, consequently, reduced food intake and body weight over time.

One Form of tDCS Does Not Fit All: The intersectionality of severity level and expected tDCS benefit

AbstractBackgroundWe investigated if a mixed group of people living with dementia (Alzheimer’s Disease (n = 16) or Frontotemporal dementia (n = 8)) would have faster response times on an N‐Back task (1‐back), a measure of working memory, after practicing the task with 20 minutes of tDCS, versus an analogous placebo condition. Crucially, half of these participants were slower than normal on the task at baseline, while the other half has normal response times. Our primary outcome measure was improvement on the MMSE task.MethodEach participant practiced the n‐back in three separate nine‐session rounds, two months apart, with a different form of stimulation in each round: (1) 4mA unilateral stimulation, with one anode electrode over the left dorsolateral prefrontal cortex area and a cathode electrode over the occipital lobe area; (2) 4mA bilateral stimulation, using the same configuration, but with an extra active anode electrode over the right dorsolateral prefrontal cortex, and (3) SHAM stimulation.ResultWe found the condition x time x severity variable was significant (F (12, 264) = 2.17, p < .05), which suggests the results founds were dependent both of the tDCS montage received and the initial severity level of the participants. More specifically, as supported by post‐hoc tests, participants initially impaired on the N‐Back task improved on the MMSE when they received the bilateral tDCS montage, but those participants with normal response times improved on the MMSE when they received the unilateral tDCS montage.ConclusionConsistent with past studies, results suggest tDCS can be used to improve cognition in people living with dementia. Optimization, however, may depend both on the montage applied and the indiosyncratic nature of the participant. A bilateral montage, for example, that theoretically impacts a wider range of brain areas, may be superior to a unilateral one when people with dementia exhibit a greater degree of impairment.

One Form of tDCS Does Not Fit All: The intersectionality of severity level and expected tDCS benefit

AbstractBackgroundWe investigated if a mixed group of people living with dementia (Alzheimer’s Disease (n = 16) or Frontotemporal dementia (n = 8)) would have faster response times on an N‐Back task (1‐back), a measure of working memory, after practicing the task with 20 minutes of tDCS, versus an analogous placebo condition. Crucially, half of these participants were slower than normal on the task at baseline, while the other half has normal response times. Our primary outcome measure was improvement on the MMSE task.MethodEach participant practiced the n‐back in three separate nine‐session rounds, two months apart, with a different form of stimulation in each round: (1) 4mA unilateral stimulation, with one anode electrode over the left dorsolateral prefrontal cortex area and a cathode electrode over the occipital lobe area; (2) 4mA bilateral stimulation, using the same configuration, but with an extra active anode electrode over the right dorsolateral prefrontal cortex, and (3) SHAM stimulation.ResultWe found the condition x time x severity variable was significant (F (12, 264) = 2.17, p < .05), which suggests the results founds were dependent both of the tDCS montage received and the initial severity level of the participants. More specifically, as supported by post‐hoc tests, participants initially impaired on the N‐Back task improved on the MMSE when they received the bilateral tDCS montage, but those participants with normal response times improved on the MMSE when they received the unilateral tDCS montage.ConclusionConsistent with past studies, results suggest tDCS can be used to improve cognition in people living with dementia. Optimization, however, may depend both on the montage applied and the indiosyncratic nature of the participant. A bilateral montage, for example, that theoretically impacts a wider range of brain areas, may be superior to a unilateral one when people with dementia exhibit a greater degree of impairment.

Comparative short-term safety and efficacy of hypnotics: A quantitative risk-benefit analysis.

Several professional societies have provided recommendations for prescribing medications for insomnia. None has provided an integrative analysis that concurrently quantifies safety and efficacy (e.g., risk-benefit ratios). This represents an important gap for informing clinician decision-making. Accordingly, the aim of the present review is to provide such an analysis for five classes of sleep-promoting medications. Adverse event data values were extracted from the most recent FDA-approved package inserts and converted to an integer before being placebo-adjusted and standardized as a rate per 1000 (AEr). Efficacy data, pre-to-post self-reported data for active and placebo conditions were acquired from pivotal trials identified in "white papers" and systematic reviews/meta-analyses. Weighted effect sizes were calculated for subjective sleep latency, wake time after sleep onset and total sleep time, and then were averaged by medication class for each sleep continuity variable. Overall efficacy was represented by a single variable, SWT (sleep latency + wake time after sleep onset + total sleep time). Risk-benefit was represented using a simple ratio value. For safety, it was found that melatonin receptor agonists had the lowest adverse event rate (AEr = 43.1), and non-benzodiazepine benzodiazepine receptor agonists had the highest rate (AEr = 255.0). For efficacy, it was found that the pre-to-post placebo adjusted effect sizes were largest for benzodiazepines (effect size = 1.94) and smallest for melatonin receptor agonists (effect size = 0.109). For risk-benefit, histamine antagonist had the most favourable profile (risk-benefit = 69.5), while melatonin receptor agonist had the least favourable profile (risk-benefit = 395.7). Overall, the combined metric for risk-benefit suggests that treatment with a histamine antagonist is optimal and potentially represents the best first-line therapy for the medical management of insomnia.

A brief nonattachment intervention based on the three marks of existence: development, rationale, and initial evidence

ABSTRACT Background The practices described in Buddhist philosophy are essentially a suite of non-theistic cognitive and behavioral interventions designed to induce nonattachment (N-A), which can be defined in terms of the absence of a need for one’s personal reality to be other than it is. Although meditative practices have received attention in multiple literatures, the cognitive analogs to these behaviorally-oriented practices have not. Design Two experiments involving undergraduate participants (total N = 239; M age = 19.04) investigated whether the provision of wisdom related to the Three Marks of Existence (i.e., some degree of suffering is inevitable, there is impermanence, and many events are not in our control) could result in (1) higher nonattachment attitudes, (2) lower threat appraisals, (3) lower stressor reactivity, and (4) shorter emotion reaction durations. Results With moderate to large effect sizes, the Three Marks trainings (relative to placebo or control conditions) resulted in (1) higher nonattachment attitudes, (2) lower threat appraisals, (3) no differences in negative emotional intensity, but 4) shorter emotion durations. Conclusions These results provide preliminary evidence that enduring cognitive trainings such as the Three Marks can be an effective tool to increase acceptance-related attitudes while attenuating negative reactivity.

Acute Low and Moderate Doses of CaffeineImprove Aerobic Endurance but Not Throwing Velocity in Trained Female Handball Players

Handball is a high-intensity team sport requiring muscle power and high aerobic capacity. Caffeine is a commonly used ergogenic aid known to enhance sports performance. However, its effects on female handball players remain unclear. This study aims to investigate the effects of acute low (LCAF) and moderate (MCAF) doses of caffeine intake on aerobic endurance and throwing velocity in trained female handball players. Fifteen trained female handball players participated in this randomized, double-blind, crossover study. Participants completed four sessions, including a familiarization session and three test sessions. The test sessions involved ingesting either 3 mg/kg (LCAF) or 6 mg/kg (MCAF) of caffeine or a placebo (PLA). Throwing velocity and aerobic endurance were measured using a hand radar gun and the Yo-Yo Intermittent Recovery Test Level 1, respectively. The results showed a significant improvement in aerobic endurance with both LCAF and MCAF doses of caffeine compared to the PLA condition (f= 5,993; p= ,014; η2= ,480). However, there was no significant difference in throwing velocity between the caffeine and placebo conditions (f= ,040; p= ,961; η2= ,006). Acute LCAF and MCAF doses of caffeine supplementation can enhance aerobic endurance but do not affect throwing velocity in trained female handball players. These findings contribute to the limited literature on the effects of caffeine in trained female handball players and suggest that caffeine may be a useful nutritional strategy for improving performance in this sport.

Applying a drift diffusion model to test the effect of oxytocin on attentional biases in body dysmorphic disorder

Individuals with body dysmorphic disorder (BDD) display selective attentional biases to threat. Oxytocin is an endogenous neuropeptide proposed to modulate attentional salience in social contexts. We conducted a secondary analysis applying drift diffusion modeling (DDM) to test whether individuals with BDD would display an attentional bias to threat, and whether oxytocin would modulate this bias. Eighteen participants with BDD and 15 healthy controls received an oxytocin or placebo nasal spray during two study visits, in randomized order, and completed a modified spatial cueing paradigm. DDM successfully parsed distinct task components demonstrating a selective attentional bias to disgust versus neutral faces in BDD compared to controls in the placebo condition, and a main effect of oxytocin on exacerbating this bias across participants. There were no effects using mean reaction time measures. DDM may reveal insights about attentional biases by utilizing trial-wise information. Oxytocin may exacerbate attentional biases to threat in BDD. General scientific summaryDrift diffusion modeling successfully parsed distinct components of a modified spatial cueing task that assessed attentional biases in those with body dysmorphic disorder (BDD) and healthy controls that were missed in conventional analyses using mean reaction time measures. Individuals with BDD displayed an attentional preference for disgust versus neutral faces in the placebo condition, and oxytocin exacerbated this attentional bias.

Acute effects of mifepristone on emotional processing related brain activity: A functional MRI study

The Hypothalamic-pituitary-adrenal (HPA) axis plays an important role in the pathophysiology of mood disorders, and preliminary data suggests that glucocorticoid receptor (GR) antagonism may be an important therapeutic mechanism. The effects of modulating HPA axis function on emotional processing related brain activity, which may be abnormal in depressed mood, is poorly understood. This study used a pharmacological functional magnetic resonance imaging (fMRI) design to determine the effects of the GR and progesterone receptor antagonist mifepristone on emotional faces processing task related brain activations in 19 right-handed healthy male participants. Each participant received 600 mg mifepristone or placebo on two separate imaging days and then performed an emotional processing fMRI task four hours later. The effect of mifepristone on task related brain activations was determined using Region-of-Interest (ROI) analyses and an exploratory whole brain voxel-wise analyses. No significant changes were observed in the defined ROIs (amygdala, anterior cingulate cortex, insula) or in the exploratory whole brain analyses that was associated with mifepristone administration in either the angry vs happy faces or angry and happy faces vs implicit baseline contrasts. Task reaction times and accuracy were similar in both mifepristone and placebo conditions (all p > 0.05). Our study failed to show significant evidence of modulation of emotional processing related brain activity associated with acute mifepristone administration. Future research should use fMRI to investigate the longer-term administration effects of mifepristone on mood in healthy participants and people with mood disorders to provide a deeper understanding of the potential effects on depressive symptoms.

A Nutritional Supplement as Adjuvant of Gabapentinoids for Adults with Neuropathic Pain following Spinal Cord Injury and Stroke: Preliminary Results.

Gabapentinoids are first choice drugs for central neuropathic pain (CNP) despite limited evidence of efficacy and side effects affecting therapy outcomes. Nutraceuticals could improve their efficacy and tolerability. Our aim is to investigate the effect of NACVAN®, in addition to gabapentinoids, on pain symptomatology in CNP patients. The effect of 6 weeks of treatment of NACVAN® was preliminary observed among 29 adult inpatients with spinal cord injury (SCI) or stroke-related CNP recruited to the experimental group. Pain intensity, neuropathic pain, and quality-of-life were measured at baseline (T0) and after 3 (T1) and 6 weeks (T2). Change in each outcome over time was assessed through a repeated measures analysis of variance or Wilcoxon matched-pairs test. Preliminary results show a significant reduction in pain intensity (T0 → T1, p = 0.021; T0 → T2, p = 0.011; T1 → T2, p = 0.46), neuropathic symptoms (T0 → T1, p = 0.024; T0 → T2, p = 0.003), and evoked pain (T0 → T2, p = 0.048). There were no significant reductions in other neuropathic pain dimensions and in quality-of-life components. No side-effects were detected. NACVAN® could have a beneficial adjuvant effect when used as an add-on to gabapentinoids in patients suffering from CNP due to SCI or stroke, with no adverse effect. Future analysis on a larger sample, compared with a placebo condition, could confirm these preliminary results.

Effects of an open-label placebo intervention on reactions to social exclusion in healthy adults: a randomized controlled trial

Social exclusion, that is being left out by others, can have adverse consequences for individuals’ psychological well-being. Even short-term experiences of social exclusion strongly threaten basic psychological needs and cause so-called social pain. Prior research suggests an overlap between the experience of social and physical pain that, amongst others, is reflected by the effectiveness of physical pain treatments in alleviating social pain. Drawing upon these prior findings, we here explore whether open-label placebos, which have previously been found to be effective in reducing physical pain, can alleviate social pain following social exclusion. Seventy-four healthy participants were randomly assigned to one of four conditions in a 2 × 2 between-subjects design: First, they either received an open-label placebo intervention or no treatment. Second, they either experienced inclusion or exclusion by their co-players in the interactive ball-tossing game Cyberball. We find that excluded participants in the open-label placebo condition experienced significantly less hurt feelings compared to those in the control condition (Cohen’s d = 0.77). There was no effect of treatment for need threat. The findings suggest new possibilities to alleviate social pain, which is of particular interest in the context of preventing destructive and maladaptive behaviors in situations where functional coping strategies are unavailable.

Choice Enhances Placebo Hypoalgesia More in Weaker Placebo Contexts: A Partial Reinforcement Study

Providing individuals with choice over treatment has been found to enhance placebo hypoalgesia. However, this choice effect is not always present. The current study tested whether the strength of the placebo context influenced the effect of choice on placebo hypoalgesia. Using an established electrocutaneous pain paradigm, the choice effect was compared when placebo hypoalgesia was induced by Continuous Reinforcement (CRF) (strong placebo context) versus partial reinforcement (PRF) (weak placebo context). Healthy volunteers (N = 133) were randomized to receive either choice over treatment administration or no choice and then to placebo conditioning under either CRF (placebo always followed by surreptitious pain reduction during training) or PRF (placebo only followed by surreptitious pain reduction on half of the training trials). At the test, placebo hypoalgesia was greater and more resistant to extinction overall for those with choice. Importantly, however, the choice effect in enhancing the magnitude of placebo hypoalgesia was stronger after PRF than CRF. These results indicate that choice may have greater placebo-enhancing power in weaker placebo contexts. Therefore, choice may be a cheap and effective tool for improving clinical outcomes by facilitating placebo hypoalgesia when the existing treatment context is insufficient to produce placebo hypoalgesia itself. PerspectiveThis study demonstrates that the enhancing effect of choice on placebo hypoalgesia is greater in a weaker placebo context. As such, offering choice could be an ethical way to effectively improve pain outcomes when placebo effects cannot be readily produced by the treatment context.

Effects of Aphrodite (an Herbal Compound) on SSRI-Induced Sexual Dysfunctions and Depression in Females with Major Depressive Disorder: Findings from a Randomized Clinical Trial.

Background and Objectives: Almost by default, people with major depression disorder (MDD) also report sexual health issues. This holds even more true when sexual dysfunctions are SSRI-induced. Herbal compounds may have the power to counterbalance such sexual dysfunctions, though research is still scarce. Therefore, we assessed females with diagnosed MDD treated with a standard SSRI (sertraline) and reporting SSRI-induced sexual dysfunctions, and we asked whether compared to placebo, Aphrodite (a blend of ginger, saffron, cinnamon, thistle, and Tribulus terrestris) may favorably impact on sexual dysfunctions, and on symptoms of depression, anxiety, and sleep disturbances. Materials and Methods: A total of 41 females (mean age: 35.05 years) with diagnosed MDD, treated with sertraline (a standard SSRI) at therapeutic dosages, and reporting SSRI-induced sexual dysfunction, were randomly assigned either to Aphrodite or to the placebo condition. At baseline and four and eight weeks later (study end), participants completed a series of self-rating questionnaires covering symptoms of sexual dysfunction, depression, anxiety, and sleep complaints. Results: Symptoms of sexual dysfunction, depression, and anxiety decreased over time, but more so in the Aphrodite condition, compared to the placebo condition (significant p-values and large effect sizes). Over time, sleep disturbances decreased irrespective of the study condition. Conclusions: The pattern of results suggests that compared to placebo, Aphrodite appeared to improve symptoms of sexual dysfunction, depression, and anxiety among females with diagnosed MDD and SSRI-induced sexual dysfunction. Further and similar studies should investigate the underlying psychophysiological mechanisms.