Deceptive and non-deceptive placebos to reduce sadness: A five-armed experimental study

Change in pain expectations but no open-label placebo analgesia: An experimental study using the heat pain paradigm

BACKGROUND

Open-label placebos (OLP) prescribed without deception and with a convincing rationale have been shown to evoke powerful treatment effects. Patients' treatment expectations seem to influence the magnitude of the effect.

OBJECTIVE

We examined if two different OLP rationales increased pain tolerance and reduced pain intensity and unpleasantness in a standardized heat pain experiment.

METHODS

Participants (N = 71) who self-reported reoccurring pain for at least the last 3 months were randomly assigned to one of three groups. We compared a personal-emotional and a scientific-matter-of-fact rationale with a control group (CG) that received the same placebo without any rationale. The rationale suggested a desensitizing effect on pain perception and improved pain coping of the placebo, whereas in the CG it was introduced as an ointment for measurement. The primary outcomes were pre-post changes in pain tolerance, expected and experienced pain intensity and unpleasantness.

RESULTS

Participants showed a decrease in expected pain intensity, but not expected pain unpleasantness for both rationales. There were no differences in pain tolerance and experienced pain intensity and unpleasantness.

CONCLUSIONS

Our study suggests that evoking positive treatment expectations is not sufficient to elicit an OLP response. Possibly, the magnitude of expectations change in this study was not powerful enough to evoke an OLP effect. Additionally, it is possible that OLP effects in pain are unrelated to positive treatment expectations. The failure of OLP in our study is in contrast to a number of previous studies examining the effects of OLP in experimental and clinical pain.

SIGNIFICANCE

This study provides evidence that positive treatment expectations are not sufficient to evoke an open-label placebo effect in a standardized heat pain experiment. We showed that two different rationales improved participants treatment expectations, but failed to evoke a placebo effect in comparison to a control group that received the same placebo, labelled as an ointment to improve measurement quality.

The role of positive information provision in open-label placebo effects

Open label placebos (OLPs) appear generally efficacious among clinical samples, but the empirical evidence regarding their use in non-clinical and sub-clinical samples, as well as when administered independent of a convincing rationale, is mixed. Healthy participants (N = 102) were randomised to either a 6-day course of OLP pills with information provision (OLP-plus: N = 35), without information provision (OLP-only: N = 35), or no-treatment control group (N = 32). OLP pills were described as enhancing physical (symptoms and sleep) and psychological (positive and negative emotional) well-being. Well-being was assessed at baseline and on Day 6. Expectancies and adherence were measured. OLP administration interacted with baseline well-being. The OLP-plus group demonstrated increased well-being on all outcomes other than positive emotions, but only when they reported decreased baseline well-being. OLP-only and control groups did not differ. The OLP-plus group demonstrated elevated expectancies, that mediated the OLP effect on physical symptoms relative to control, but only when well-being was lower than average at baseline (i.e. moderated-mediation). Results demonstrate the importance of information provided with OLPs. The moderating effect of baseline outcomes may reconcile inconsistent results regarding clinical and non-clinical samples. Accounting for baseline symptoms in non-clinical and sub-clinical samples is likely to enhance our understanding of when OLPs are effective.

Non-Deceptive Placebos Can Promote Acts of Kindness: A Randomized Controlled Trial

Placebos have often been used to reduce emotional distress but rarely to increase positive feelings. The present study investigated whether a placebo can promote acts of kindness (AoKs) that are associated with emotional well-being. A total of 160 university students were asked to perform an AoK daily for one week. They evaluated their emotional state (feelings of pleasantness, arousal, satisfaction) directly before and after the AoKs. This was monitored via a smartphone app. One group performed each AoK after taking a non-deceptive placebo; the other group received no placebo. Before and after the one-week program, the participants completed three questionnaires that assessed satisfaction with life, positive/negative affect, and flourishing. The participants reported higher pleasantness directly after engaging in an AoK and more satisfaction with life after the program. The motivation to carry out AoKs decreased strongly over the week. However, placebo receivers completed more AoKs than the no-placebo group. The results indicate that placebo treatment can promote the performance of acts of kindness.

The roles of expectation, comparator, administration route, and population in open-label placebo effects: a network meta-analysis

Three meta-analyses have demonstrated the clinical potential of open-label placebos (OLPs). However, there is a need to synthesize the existing evidence through more complex analyses that would make it possible to answer questions beyond mere efficacy. Such analyses would serve to improve the understanding of why and under what circumstances OLPs work (e.g., depending on induced expectations or across different control groups). To answer these questions, we conducted the first network meta-analyses in the field of OLPs. Our analyses revealed that OLPs could be beneficial in comparison to no treatment in nonclinical (12 trials; 1015 participants) and clinical populations (25 trials; 2006 participants). Positive treatment expectations were found to be important for OLPs to work. Also, OLP effects can vary depending on the comparator used. While the kind of administration route had no substantial impact on the OLP effects, effects were found to be larger in clinical populations than in nonclinical populations. These results suggest that the expectation, comparator, administration route, and population should be considered when designing and interpreting OLP studies.

Teenagers' and parental attitudes towards the use of placebo pills

The placebo response a significant therapeutic improvement after a placebo intervention - can be high in children. The question arises of how optimal advantages of placebo treatment in pediatric clinical care be achieved. In this era of shared-decision making, it is important to be aware of patients' and parental attitudes. Therefore, the aim of the current study was to assess teenagers' and parental views on the use of placebo pills in pediatric clinical care. All patients (aged 12-18 years) and parents of children (aged 0-18 years), visiting the pediatric outpatient clinic between March 2020 through December 2020, were invited to participate in this study multicenter survey study. Of 1644 distributed questionnaires: 200/478 (47%) teenagers and 456/1166 (45%) parents filled out the complete survey. More parents were positive towards prescribing placebo medication than teenagers (80% vs. 71%, p = .019), especially when the clinician disclosed the use of a placebo to parents and teenagers, respectively (76% vs. 55%, p = .019). Increasing age of teenagers was positively associated with the willingness for placebo interventions (OR 0.803, 95%CI 0.659-0.979), as was a higher level of parental education (OR 0.706, 95%CI 0.526-0.949).  Conclusion: This study emphasizes the willingness of teenagers and parents to receive placebo medication. Placebo medication becoming more acceptable and integrated into daily care may contribute to a decrease in medication use. What is Known: • A placebo is a treatment without inherent power to produce any therapeutic effect, but can result in significant therapeutic improvement, the so-called placebo response. • Treatment response rates after placebo interventions in children can be high, ranging from 41 to 46% in pediatric trials. What is New: • Most teenagers (71%) and parents (80%) find it appropriate for healthcare professionals to prescribe placebo medication. • Compared to adult care, pediatrics has a unique feature to disclose placebo treatment to parents while concealing it for the young patient: the majority of teenagers (85%) and parents (91%) agree to disclose placebo treatment to parents exclusively.

Reduction in caffeine withdrawal after open-label decaffeinated coffee

BACKGROUND

Withdrawal from addictive drugs can be reduced by administering placebo deceptively, but in the clinic it is unethical to deceive the patient. Open-label placebo effects have been observed across a range of psychophysiological phenomena, and may also apply to drug withdrawal.

METHOD

24-hour abstinent heavy coffee drinkers (N = 61) rated their caffeine withdrawal symptoms before being allocated to one of three groups. The Deceptive group was given decaffeinated coffee (decaf) and told it was caffeinated, the Open-Label group given decaf and told it was decaf and the Control group given water and told it was water. After 45 min, caffeine withdrawal was measured again. All participants rated their expectancies of withdrawal reduction from caffeinated coffee, decaf and water prior to being randomised and the end of the study.

RESULTS

There was a significant 9.5-point reduction in caffeine withdrawal in the Open-Label group (95% confidence interval (CI): 4.7, 14.3; p = 0.002), which was 8.6 points less than the Deceptive group (95%CI: 0.4, 16.8; p = 0.014) but 8.9 points greater than the Control group (95%CI: 0.6, 17.2; p = 0.012). Pre-randomisation, participants expected caffeinated coffee to reduce their withdrawal symptoms the most, followed by water and decaf, Pre-randomisation expectancy of withdrawal was only associated with amount of withdrawal reduction in the Deceptive group.

CONCLUSION

It appears as if open-label placebo caffeine (i.e. decaf) can reduce caffeine withdrawal symptoms, even when people do not hold a conscious expectancy it will do so. There may be ways to integrate open-label placebo procedures into clinical interventions for drug dependence without violating informed consent.

Deceptive and open-label placebo effects in experimentally induced guilt: a randomized controlled trial in healthy subjects

Placebos are known to yield significant effects in many conditions. We examined deceptive and open-label placebo effects on guilt, which is important for self-regulation and a symptom of mental disorders. Following an experimental induction of guilt, healthy subjects were randomized to deceptive placebo (DP; n = 35), open-label placebo (OLP; n = 35), or no treatment (NT; n = 39). The primary outcome was guilt responses assessed in area under the curve (AUC). Secondary outcomes were shame, guilt, and affect. We hypothesized that DP and OLP would reduce guilt compared to NT. Guilt responses were higher in the NT group than in the placebo groups (estimate = 2.03, 95% CI = 0.24-3.82, d = 0.53), whereas AUC guilt did not differ significantly between the placebo groups (estimate = -0.38, 95% CI = -2.52-1.76, d = -0.09). Placebos are efficacious in reducing acute guilt responses, regardless of the placebo administration (i.e., open vs. deceptive). Furthermore, we observed narrative-specific effects with significant changes of guilt but not shame, pride, or affect. These results indicate not only that guilt is amenable to placebos but also that placebos can be administered in an ethical and potentially emotion-specific manner.

Can placebos reduce intrusive memories?

After traumatic experiences, intrusive memories can flash back and evoke significant distress. Here, we investigated whether the frequency and severity of intrusions can be reduced by the provision of placebo. After the (online) exposure to the trauma-film paradigm, healthy participants (N = 112) received deceptive placebo (DP), open-label placebo (OLP), or no treatment. In the DP group, participants were led to believe to receive a dopamine-modulating drug, which was supposed to disrupt the consolidation of traumatic memories, although they in fact received the same placebo tablets as the OLP group for one week. The results show that the groups did not differ in the frequency of intrusive memories after one week. However, participants receiving OLP reported a significantly reduced intensity of intrusions as compared to DP. Across groups, negative expectations about the intensity and controllability of intrusions were associated with a higher frequency of intrusions, higher distress, higher burden, and more negative appraisal. The results suggest that expectations play an important role in the emergence of intrusive memories and that some of the disabling aspects of intrusive memories can be reduced by placebo. This may carry clinical potential because placebos are an accessible, cost-effective intervention to reduce the risk of intrusive memories.