Numerous studies have demonstrated that associative learning can affect visual cognition. In one such effect, search times for a target hidden among similar distractors are faster for repeated search ...configurations compared with novel configurations. This contextual cuing effect is particularly interesting, because researchers routinely have failed to find evidence of recognition of the repeated configurations, concluding that the effect is a form of nonconscious learning. Vadillo, Konstantinidis, and Shanks (
2016
) recently criticized this conclusion on a number of methodological and conceptual grounds that suggest the area suffers from a high probability of false-negative results on awareness tests and misinterpretation of weak or absent relationships between cuing and awareness measures. We developed further predictions from theoretical models assuming that single or independent memory sources drive learning and awareness and discuss how these predictions fare in three new contextual cuing experiments involving large (n > 60) and very large samples (n > 600). The data support the absence of a positive relationship between recognition and the cuing effect both at the participant and configuration level, the probability of which being a false negative is very low in a model assuming a single memory source drives learning and awareness. This was the case using both conventional and Bayesian analyses. The combination of this theoretical and empirical analysis suggests that contextual cuing is not dependent on cue recognition and provides evidence that it reflects a genuine form of nonconscious learning.
•Successful blinding is an important feature of double-blind randomized controlled trials, and ensures that the safety and efficacy of treatments are accurately appraised.•In a range of fields (e.g. ...chronic pain, general medicine), few trials report assessing the success of blinding.•We do not know the frequency or success of blinding assessment among antidepressant RCTs within depression.•Only 4.7% of RCTs examining antidepressants in depression assess blinding.•Overall, blinding is not successful among either patients or investigators.
Successful blinding in double-blind RCTs is crucial for minimizing bias, however studies rarely report information about blinding. Among RCTs for depression, the rates of testing and success of blinding is unknown. We conducted a systematic review and meta-analysis of the rates of testing, predictors, and success of blinding in RCTs of antidepressants for depression. Following systematic search, further information about blinding assessment was requested from corresponding authors of the included studies. We reported the frequency of blinding assessment across all RCTs, and conducted logistic regression analyses to assess predictors of blinding reporting. Participant and/or investigator guesses about treatment allocation were used to calculate Bang's Blinding Index (BI). The BI between RCT arms was compared using meta-analysis. Across the 295 included trials, only 4.7% of studies assessed blinding. Pharmaceutical company sponsorship predicted blinding assessment; unsponsored trials were more likely to assess blinding. Meta-analysis suggested that blinding was unsuccessful among participants and investigators. Results suggest that blinding is rarely assessed, and often fails, among RCTs of antidepressants. This is concerning considering controversy around the efficacy of antidepressant medication. Blinding should be routinely assessed and reported in RCTs of antidepressants, and trial outcomes should be considered in light of blinding success or failure.
Background: Placebo and nocebo effects occur in clinical or laboratory medical contexts after administration of an inert treatment or as part of active treatments and are due to psychobiological ...mechanisms such as expectancies of the patient. Placebo and nocebo studies have evolved from predominantly methodological research into a far-reaching interdisciplinary field that is unravelling the neurobiological, behavioural and clinical underpinnings of these phenomena in a broad variety of medical conditions. As a consequence, there is an increasing demand from health professionals to develop expert recommendations about evidence-based and ethical use of placebo and nocebo effects for clinical practice. Methods: A survey and interdisciplinary expert meeting by invitation was organized as part of the 1st Society for Interdisciplinary Placebo Studies (SIPS) conference in 2017. Twenty-nine internationally recognized placebo researchers participated. Results: There was consensus that maximizing placebo effects and minimizing nocebo effects should lead to better treatment outcomes with fewer side effects. Experts particularly agreed on the importance of informing patients about placebo and nocebo effects and training health professionals in patient-clinician communication to maximize placebo and minimize nocebo effects. Conclusions: The current paper forms a first step towards developing evidence-based and ethical recommendations about the implications of placebo and nocebo research for medical practice, based on the current state of evidence and the consensus of experts. Future research might focus on how to implement these recommendations, including how to optimize conditions for educating patients about placebo and nocebo effects and providing training for the implementation in clinical practice.
Individuals with chronic pain demonstrate attentional biases (ABs) towards pain-related stimuli. However, the clinical importance of these biases is yet to be determined and a sound theoretical model ...for explaining the role of ABs in the development and maintenance of pain is lacking. Within this article, we (1) systematically review prospective and experimental research exploring ABs and pain outcomes in light of current theoretical models and (2) propose a theoretical framework for understanding AB in pain. Across prospective research, an attentional pattern of vigilance-avoidance was observed. Interventions targeting ABs were less consistent; however, there were promising findings among studies that found attentional training effects, particularly for laboratory research. The proposed Threat Interpretation Model suggests a relationship between threat, interpretation, and stimuli in determining attentional processes, which while tentative generates important testable predictions regarding the role of attention in pain and builds on previous theoretical and empirical work in this area.
Positive framing has been proposed as an intervention to increase COVID-19 vaccination intentions. However, available research has examined fictitious or unfamiliar treatments. This pre-registered ...study (aspredicted#78369) compared the effect of standard negatively framed EU patient information leaflets (PILs), with new positively framed PILs, on booster intentions (measured pre- and post-intervention) for AstraZeneca, Pfizer, and Moderna COVID-19 vaccines. A representative sample of 1222 UK-based adults was randomised to one of six groups in a factorial design with framing (Positive vs. Negative) and vaccine familiarity (same (as previous), familiar, unfamiliar) as factors. The benefit of positive framing was hypothesised to be strongest for the least familiar vaccine (Moderna). Framing was moderated by familiarity, where only the unfamiliar vaccine showed a benefit of positive relative to negative Framing. Framing and familiarity also interacted with baseline Intention with the effect of framing on the unfamiliar vaccine especially pronounced at low baseline Intent. Conversely, standard negative framing appeared to increase intentions for familiar vaccines at low baseline intent. Findings provide important evidence that positive framing could improve vaccine uptake globally when switches or new developments require individuals to receive less familiar vaccines. Positive framing of familiar vaccines, however, should be treated with caution until better understood.
As the global pandemic perpetuates, keeping the population vaccinated will be imperative to maintain societal protection from the SARS-CoV-2 (COVID-19) virus. However, while empirical evidence ...regarding predictors of the intention to receive a first COVID-19 vaccine has amassed, our understanding regarding the psychological and behavioral drivers of continued COVID-19 vaccination remains limited. In this pre-registered study (UK: AsPredicted#78370|Australia: AsPredicted#81667), factors predicting the intention to receive a COVID-19 booster vaccine were investigated in two adult samples from the UK (N = 1222) and Australia (N = 1197) that were nationally representative on factors of age, gender, and geographic location. High levels of booster intent were found (73% and 67%, respectively). Exploratory Structural Equation Modelling (ESEM) revealed three key predictors of the intention to receive a booster vaccine that emerged across both UK and Australian samples: concern regarding the COVID-19 virus, positive perceptions of the COVID-19 vaccines, and the perceived severity of side effects experienced to the last COVID-19 vaccine dose. Several additional factors (age, months since the last COVID-19 vaccine, familiarity with side effects, and regularly receiving the influenza vaccine) were present in the Australian dataset. These findings provide important evidence that targeting psychological perceptions of the COVID-19 vaccine and virus may serve to maintain participation in the COVID-19 vaccination programme, paving the way for future behavioural research in this area.
Although critical for informed consent, side effect warnings can contribute directly to poorer patient outcomes because they often induce negative expectations that trigger nocebo side effects. ...Communication strategies that reduce the development of nocebo side effects whilst maintaining informed consent are therefore of considerable interest. We reviewed theoretical and empirical evidence for the use of framing strategies to achieve this. Framing refers to the way in which information about the likelihood or significance of side effects is presented (e.g., negative frame: 30%
experience headache vs. positive frame: 70% will
experience headache), with the rationale that positively framing such information could diminish nocebo side effects. Relatively few empirical studies (
= 6) have tested whether framing strategies can reduce nocebo side effects. Of these, four used attribute framing and two message framing. All but one of the studies found a significant framing effect on at least one aspect of side effects (e.g., experience, attribution, threat), suggesting that framing is a promising strategy for reducing nocebo effects. However, our review also revealed some important open questions regarding these types of framing effects, including, the best method of communicating side effects (written, oral, pictorial), optimal statistical presentation (e.g., frequencies vs. percentages), whether framing affects perceived absolute risk of side effects, and what psychological mechanisms underlie framing effects. Future research that addresses these open questions will be vital for understanding the circumstances in which framing are most likely to be effective.
Evidence suggests that transcranial Direct Current Stimulation (tDCS) has antidepressant effects in unipolar depression, but there is limited information for patients with bipolar depression. ...Additionally, prior research suggests that brain derived neurotrophic factor (BDNF) Val66Met genotype may moderate response to tDCS.
To examine tDCS efficacy in unipolar and bipolar depression and assess if BDNF genotype is associated with antidepressant response to tDCS.
130 participants diagnosed with a major depressive episode were randomized to receive active (2.5 milliamps (mA), 30 min) or sham (0.034 mA and two 60-second current ramps up to 1 and 0.5 mA) tDCS to the left prefrontal cortex, administered in 20 sessions over 4 weeks, in a double-blinded, international multisite study. Mixed effects repeated measures analyses assessed change in mood and neuropsychological scores in participants with at least one post-baseline rating in the unipolar (N = 84) and bipolar (N = 36) samples.
Mood improved significantly over the 4-week treatment period in both unipolar (p = 0.001) and bipolar groups (p < 0.001). Among participants with unipolar depression, there were more remitters in the sham treatment group (p = 0.03). There was no difference between active and sham stimulation in the bipolar sample. BDNF genotype was unrelated to antidepressant outcome.
Overall, this study found no antidepressant difference between active and sham stimulation for unipolar or bipolar depression. However, the possibility that the low current delivered in the sham tDCS condition was biologically active cannot be discounted. Moreover, BDNF genotype did not moderate antidepressant outcome.
www.clinicaltrials.gov, NCT01562184.
•Active tDCS was not found to be significantly more efficacious than sham tDCS.•It is possible that the low level current present in sham tDCS had active effects.•Efficacy of tDCS did not differ for unipolar and bipolar depressed participants.•Brain derived neurotrophic factor genotype was not associated with response to tDCS.
ObjectivesTo compare attitudes of mental health (MH) professionals towards trials of methylenedioxymethamphetamine-assisted psychotherapy (MDMA-AP), with a neutrally labelled pharmacotherapy ...trial.DesignA randomised controlled vignette study design, with experimenters blinded to group condition.SettingParticipants were recruited online via professional societies.ParticipantsPsychiatrists, psychologists and MH researchers from across Australia.InterventionsParticipants were randomly allocated to read a vignette about a trial of either MDMA-AP or a neutrally labelled pharmacotherapy.OutcomesComparison of the difference in four attitudes towards MDMA-AP and control: How likely they were to (1) recommend participating, or (2) object to participating in the trial; (3) their predicted efficacy; and (4) concerns about the safety of the trial.ResultsThere were no overall differences between professional’s attitudes towards MDMA-AP (n=51) and the control pharmacotherapy (n=43) trial vignettes. Psychiatrists were less likely to recommend participation in the MDMA-AP than the control trial (d=0.72, p=0.02), but did not differ in other attitudes. Psychologists and researchers did not differ in any attitudes. The correlation between professional experience and both: (1) concern about, and (2) strength of objection to, the trial, was higher for MDMA-AP, than control (d=0.60, p=0.01 and d=0.40, p=0.03, respectively).ConclusionsPsychiatrists, but not psychologists or researchers showed more hesitancy in recommending trials of MDMA-AP versus an unknown pharmacotherapy. Experienced MH professionals were more likely to have negative views about MDMA-AP trials than less experienced MH professionals. This may reflect the experience of prior unfulfilled pharmacotherapy innovation or exuberance associated with fewer years of practice. Research into, and implementation of, MDMA-AP may face barriers with certain MH professionals, which will need be addressed if MDMA-AP continues to show promise as an efficacious treatment.Trial registration numberThe study design was registered with the ANZCTR (ACTRN12620001068954).
While social media exposure is known to influence vaccine hesitancy, its impact on postvaccination experience remains relatively unknown. This retrospective cross-sectional study explored whether ...various psychosocial and individual factors moderate the association between social media exposure to personal recounts of COVID-19 vaccine side effects and the viewer’s subsequent postvaccination side effect experience. Adults residing in Australia, who were fully vaccinated with two COVID-19 vaccine doses (n = 280) completed an online survey. The more severe the personal recounts of post-COVID-19 vaccination side effects participants were exposed to on social media, the more severe their own postvaccination side effects were following both their first (β = 0.261, p < 0.001) and second dose (β = 0.299, p < 0.001). This association was stronger among those with greater vaccine side effect worry, elevated negative emotional states such as anxiety and stress, and a stronger proclivity for using social media over mainstream media for COVID-19 vaccine side effect information. As such, not only does social influence appear to exacerbate or trigger postvaccination side effects, but a range of psychosocial and situational factors moderate this association. Health organisations and government bodies could minimise the negative effects of social media exposure in future health outbreaks by countering treatment misperceptions on social media platforms as they arise.
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