"Ready-to-use" two-week home exercise program targeting depressive symptoms: pilot study.

Exercise is an evidence-based treatment for depressive symptoms, yet it often requires specialised knowledge, equipment, or professional supervision. Lay people in certain contexts, for example in remote locations or under pandemic restrictions, often lack these resources and thus cannot use exercise to manage their depressive symptoms. We developed a two-week home exercise program that bypasses these barriers and tested it in university students during pandemic restrictions. In an online study, we recruited 49 participants to complete a week of baseline symptom monitoring then follow the exercise program for 2 weeks (6 sessions) at home. The exercise program involved aerobic and resistance training; each session lasted approximately 45 min. After 2 weeks of the intervention, participants reported lower depressive (standardised ß = -0.71 [-1.05, -0.38]) and anxiety (ß = -0.87 [-1.19, -0.55]) symptoms. Although we cannot make causal conclusions, our results suggest that the brief home exercise program may have potential to reduce depressive symptoms in young adults.

Presenting a sham treatment as personalised increases the placebo effect in a randomised controlled trial.

Background: Tailoring interventions to patient subgroups can improve intervention outcomes for various conditions. However, it is unclear how much of this improvement is due to the pharmacological personalisation versus the non-specific effects of the contextual factors involved in the tailoring process, such as the therapeutic interaction. Here, we tested whether presenting a (placebo) analgesia machine as personalised would improve its effectiveness. Methods: We recruited 102 adults in two samples (N1=17, N2=85) to receive painful heat stimulations on their forearm. During half of the stimulations, a machine purportedly delivered an electric current to reduce their pain. The participants were either told that the machine was personalised to their genetics and physiology, or that it was effective in reducing pain generally. Results: Participants told that the machine was personalised reported more relief in pain intensity than the control group in both the feasibility study (standardised ß=-0.50 [-1.08, 0.08]) and the pre-registered double-blind confirmatory study (ß=-0.20 [-0.36, -0.04]). We found similar effects on pain unpleasantness, and several personality traits moderated the results. Conclusions: We present some of the first evidence that framing a sham treatment as personalised increases its effectiveness. Our findings could potentially improve the methodology of precision medicine research and inform practice. Funding: This study was funded by the Social Science and Humanities Research Council (93188) and Genome Québec (95747).

Precision treatments are therapies that are tailored to a patient's individual biology with the aim of making them more effective. Some cancer drugs, for example, work better for people with specific genes, leading to improved outcomes when compared to their 'generic' versions. However, it is unclear how much of this increased effectiveness is due to tailoring the drug's chemical components versus the contextual factors involved in the personalisation process. Contextual factors like patient beliefs can boost a treatment's outcomes via the 'placebo effect' ­ making the intervention work better simply because the patient believes it to. Personalised treatments typically combine more of these factors by being more expensive, elaborate, and invasive ­ potentially boosting the placebo effect. Sandra et al. tested whether simply describing a placebo machine ­ which has no therapeutic value ­ as personalised would increase its effectiveness at reducing pain for healthy volunteers. Study participants completed several sham physiological and genetic tests. Those in the experimental group were told that their test results helped tailor the machine to increase its effectiveness at reducing pain whereas those in the control group were told that the tests screened for study eligibility. All volunteers were then exposed to a series of painful stimuli and used the machine to reduce the pain for half of the exposures. Participants that believed the machine was personalised reported greater pain relief. Those with a stronger desire to be seen as different from others ­ based on the results of a personality questionnaire ­ experienced the largest benefits, but only when told that the machine was personalised. This is the first study to show that simply believing a sham treatment is personalised can increase its effectiveness in healthy volunteers. If these results are also seen in clinical settings, it would suggest that at least some of the benefit of personalised medicine could be due to the contextual factors surrounding the tailoring process. Future work could inform doctors of how to harness the placebo effect to benefit patients undergoing precision treatments.

Imprinting: expanding the extra-pharmacological model of psychedelic drug action to incorporate delayed influences of sets and settings.

Background: Psychedelic drug experiences are shaped by current-moment contextual factors, commonly categorized as internal (set) and external (setting). Potential influences of past environments, however, have received little attention. Aims: To investigate how previous environmental stimuli shaped the experiences of patients receiving ketamine for treatment-resistant depression (TRD), and develop the concept of "imprinting" to account for such time-lagged effects across diverse hallucinogenic drugs. Methods: Recordings of treatment sessions and phenomenological interviews from 26 participants of a clinical trial investigating serial intravenous ketamine infusions for TRD, conducted from January 2021 to August 2022, were retrospectively reviewed. A broad literature search was undertaken to identify potentially underrecognized examples of imprinting with both serotonergic and atypical psychedelics, as well as analogous cognitive processes and neural mechanisms. Results: In naturalistic single-subject experiments of a 28-year-old female and a 34-year-old male, subjective ketamine experiences were significantly altered by varying exposures to particular forms of digital media in the days preceding treatments. Higher levels of media exposure reduced the mystical/emotional qualities of subsequent psychedelic ketamine experiences, overpowering standard intention-setting practices and altering therapeutic outcomes. Qualitative data from 24 additional patients yielded eight further spontaneous reports of past environmental exposures manifesting as visual hallucinations during ketamine experiences. We identified similar examples of imprinting with diverse psychoactive drugs in past publications, including in the first-ever report of ketamine in human subjects, as well as analogous processes known to underly dreaming. Conclusions/interpretation: Past environmental exposures can significantly influence the phenomenology and therapeutic outcomes of psychedelic experiences, yet are underrecognized and understudied. To facilitate future research, we propose expanding the contextual model of psychedelic drug actions to incorporate imprinting, a novel concept that may aid clinicians, patients, and researchers to better understand psychedelic drug effects. Clinical trial registration: ClinicalTrials.gov, identifier NCT04701866.

A Nudge-Based Intervention to Reduce Problematic Smartphone Use: Randomised Controlled Trial.

Problematic smartphone use is rising across the world. We tested an intervention with ten strategies that nudge users to reduce their smartphone use, for example by disabling non-essential notifications and changing their display to greyscale. Participants first completed baseline measures of smartphone use, well-being, and cognition before choosing which intervention strategies to follow for 2 to 6 weeks. Study 1 ( N = 51 ) used a pre-post design while study 2 ( N = 70 ) compared the intervention to a control group who monitored their screen time. Study 1 found reductions in problematic smartphone use, screen time, and depressive symptoms after 2 weeks. Study 2 found that the intervention reduced problematic smartphone use, lowered screen time, and improved sleep quality compared to the control group. Our brief intervention returned problematic smartphone use scores to normal levels for at least 6 weeks. These results demonstrate that various strategies can be combined while maintaining feasibility and efficacy.

Different Patterns of Sleep-Dependent Procedural Memory Consolidation in Vipassana Meditation Practitioners and Non-meditating Controls.

AIM: Rapid eye movement (REM) sleep, non-rapid eye movement (NREM) sleep, and sleep spindles are all implicated in the consolidation of procedural memories. Relative contributions of sleep stages and sleep spindles were previously shown to depend on individual differences in task processing. However, no studies to our knowledge have focused on individual differences in experience with Vipassana meditation as related to sleep. Vipassana meditation is a form of mental training that enhances proprioceptive and somatic awareness and alters attentional style. The goal of this study was to examine a potential role for Vipassana meditation experience in sleep-dependent procedural memory consolidation. METHODS: Groups of Vipassana meditation practitioners (N = 22) and matched meditation-naïve controls (N = 20) slept for a daytime nap in the laboratory. Before and after the nap they completed a procedural task on the Wii Fit balance platform. RESULTS: Meditators performed slightly better on the task before the nap, but the two groups improved similarly after sleep. The groups showed different patterns of sleep-dependent procedural memory consolidation: in meditators, task learning was positively correlated with density of slow occipital spindles, while in controls task improvement was positively associated with time in REM sleep. Sleep efficiency and sleep architecture did not differ between groups. Meditation practitioners, however, had a lower density of occipital slow sleep spindles than controls. CONCLUSION: Results suggest that neuroplastic changes associated with meditation practice may alter overall sleep microarchitecture and reorganize sleep-dependent patterns of memory consolidation. The lower density of occipital spindles in meditators may mean that meditation practice compensates for some of the memory functions of sleep.

Cognitive capacity limitations and Need for Cognition differentially predict reward-induced cognitive effort expenditure.

While psychological, economic, and neuroscientific accounts of behavior broadly maintain that people minimize expenditure of cognitive effort, empirical work reveals how reward incentives can mobilize increased cognitive effort expenditure. Recent theories posit that the decision to expend effort is governed, in part, by a cost-benefit tradeoff whereby the potential benefits of mental effort can offset the perceived costs of effort exertion. Taking an individual differences approach, the present study examined whether one's executive function capacity, as measured by Stroop interference, predicts the extent to which reward incentives reduce switch costs in a task-switching paradigm, which indexes additional expenditure of cognitive effort. In accordance with the predictions of a cost-benefit account of effort, we found that a low executive function capacity-and, relatedly, a low intrinsic motivation to expend effort (measured by Need for Cognition)-predicted larger increase in cognitive effort expenditure in response to monetary reward incentives, while individuals with greater executive function capacity-and greater intrinsic motivation to expend effort-were less responsive to reward incentives. These findings suggest that an individual's cost-benefit tradeoff is constrained by the perceived costs of exerting cognitive effort.