Sleep loss and risk-taking: new findings in a field that needs more clarity

Sleep deprivation attenuates neural responses to outcomes from risky decision-making

Sleep loss impacts a broad range of brain and cognitive functions. However, how sleep deprivation affects risky decision-making remains inconclusive. This study used functional MRI to examine the impact of one night of total sleep deprivation (TSD) on risky decision-making behavior and the underlying brain responses in healthy adults. In this study, we analyzed data from N = 56 participants in a strictly controlled 5-day and 4-night in-laboratory study using a modified Balloon Analogue Risk Task. Participants completed two scan sessions in counter-balanced order, including one scan during rested wakefulness (RW) and another scan after one night of TSD. Results showed no differences in participants' risk-taking propensity and risk-induced activation between RW and TSD. However, participants showed significantly reduced neural activity in the anterior cingulate cortex and bilateral insula for loss outcomes, and in bilateral putamen for win outcomes during TSD compared with RW. Moreover, risk-induced activation in the insula negatively correlated with participants' risk-taking propensity during RW, while no such correlations were observed after TSD. These findings suggest that sleep loss may impact risky decision-making by attenuating neural responses to decision outcomes and impairing brain-behavior associations.

Association between personality characteristics and sleep quality among Chinese middle-aged and older adults: evidence from China family panel studies

BACKGROUND

Poor sleep quality will have adverse effects on physical and mental health, quality of life and other aspects of middle-aged and older adults. Sleep quality is affected by many factors. Whether the sleep quality measures of the participants had changed in the previous or subsequent time period is not easily taken into account. Moreover, there have been no studies on this topic in Chinese middle-aged and older adults. The objective of this study was to mitigate the bias of sleep quality assessment, and analyze the association between personality traits and sleep quality in Chinese middle-aged and older adults.

METHODS

The data came from the China Family Panel Studies (CFPS). A total of 6031 participants aged ≥ 45 years were included in this study. Personality characteristics were evaluated based on the scores of each dimension of Big Five personality traits. Sleep duration and sleep perception were used as indicators to measure sleep quality. Logistic models were used to analyze the relationship between personality traits and sleep duration or sleep perception, respectively.

RESULTS

4.5% of the participants had abnormal sleep duration, and 14.4% had a pessimistic sleep perception. Conscientiousness was rated the highest among the personality traits (3.97 ± 0.6). Participants with higher scores for extraversion personality traits had more normal sleep duration (OR = 0.77, 95% CI: 0.64-0.93) and more optimistic sleep perception (OR = 0.86, 95% CI: 0.76-0.96). Using the Internet and feeling unwell in the past week have a moderating effect on the impact of conscientiousness personality characteristics on sleep duration or sleep perception, respectively (but not overall sleep quality). In addition, participants with a spouse or no recent physical discomfort tended to have a normal sleep duration and a more optimistic sleep perception.

CONCLUSIONS

The higher the score of extraversion personality traits, the better the overall sleep quality of middle-aged and older adults. Having a spouse and feeling unwell were the important factors affecting their sleep quality. Specific personality traits intervention should be carried out for middle-aged and older adults with poor sleep quality to make their personality traits are closer to extraversion. In addition, middle-aged and older adults without spouses should be encouraged to marry or remarry. We will strengthen health management and medical expenditures for middle-aged and older adults.

Preliminary evidence that misalignment between sleep and circadian timing alters risk-taking preferences

Decision-making has been shown to suffer when circadian preference is misaligned with time of assessment; however, little is known about how misalignment between sleep timing and the central circadian clock impacts decision-making. This study captured naturally occurring variation in circadian alignment (i.e., alignment of sleep-wake timing with the central circadian clock) to examine if greater misalignment predicts worse decision-making. Over the course of 2 weeks, 32 late adolescent drinkers (aged 18-22 years; 61% female; 69% White) continuously wore actigraphs and completed two overnight in-laboratory visits (Thursday and Sunday) in which both dim-light melatonin onset (DLMO) and behavioural decision-making (risk taking, framing, and strategic reasoning tasks) were assessed. Sleep-wake timing was assessed by actigraphic midsleep from the 2 nights prior to each in-laboratory visit. Alignment was operationalised as the phase angle (interval) between average DLMO and average midsleep. Multilevel modelling was used to predict performance on decision-making tasks from circadian alignment during each in-laboratory visit; non-linear associations were also examined. Shorter DLMO-midsleep phase angle predicted greater risk-taking under conditions of potential loss (B = -0.11, p = 0.06), but less risk-taking under conditions of potential reward (B = 0.14, p = 0.03) in a curvilinear fashion. Misalignment did not predict outcomes in the framing and strategic reasoning tasks. Findings suggest that shorter alignment in timing of sleep with the central circadian clock (e.g., phase-delayed misalignment) may impact risky decision-making, further extending accumulating evidence that sleep/circadian factors are tied to risk-taking. Future studies will need to replicate findings and experimentally probe whether manipulating alignment influences decision-making.

Mechanisms of an eHealth program targeting depression in men with overweight or obesity: A randomised trial

BACKGROUND

The SHED-IT: Recharge study demonstrated that a gender-tailored eHealth program could improve the depressive symptoms of men with overweight or obesity and low mood. This study examined whether changes in key behaviours and cognitions acted as significant mediators of this treatment effect.

METHODS

The study was a randomised controlled trial (RCT) including 125 men with overweight or obesity (mean (SD) weight 103.8 (15.8) kg), and current depressive symptoms (Patient Health Questionnaire (PHQ-9) ≥ 5; mean (SD) 9.2 (4.1) units). Assessments were held at baseline, 3 months (post-intervention), and 6 months (follow-up). Depressive symptoms were assessed using the validated PHQ-9 and Masculine Depressive Risk Scale (MDRS-22). Behavioural and cognitive mediators were assessed with validated measures. Intention-to-treat mediation analyses were conducted using the PROCESS macro in SPSS.

RESULTS

Single mediation analyses demonstrated that the intervention effect on both PHQ-9 and MDRS-22 scores was significantly mediated by changes in MVPA, energy-dense nutrient-poor foods, cognitive flexibility, and behavioural activation. In addition, changes in sleep quality mediated improvements in MDRS-22 scores. No mediation effects were observed for light physical activity, sedentary behaviour, fruit and vegetable intake, risky alcohol consumption or mindfulness.

LIMITATIONS

The study was a secondary analysis with power to detect moderate-to-large mediation effects only.

CONCLUSION

To prevent or treat depression in men with overweight or obesity, early evidence suggests MVPA, sleep quality, energy-dense nutrient-poor food intake, cognitive flexibility, and behavioural activation are important intervention targets.

The Relationship Between Digital Activity and Bedtime, Sleep Duration, and Sleep Quality in Chinese Working Youth

PURPOSE

The study aims to examine whether and how digital activities influence sleep issues among working Chinese youth.

METHODS

This study used data from the China Family Panel Studies (CFPS) a Chinese population-based survey, and employed the multilevel ordinal logistic regression model (MOLRM) to test the associations between digital engagement (whether to engage in digital activity, frequency, and duration) and sleep issues (bedtime, sleep duration, and quality) among Chinese working youth. Additionally, the restricted cubic spline model (RCSM) was adopted to fit the MOLRM to evaluate the nonlinear relationship between digital activity duration and sleep quality, and thus determine the optimal range of digital activity duration.

RESULTS

The analysis included 7849 working young adults. The digital usage rate was 84.11%. Digital use was not significantly associated with average, workday, or free-day sleep duration, after controlling for all potential confounders. However, most digital activity indicators could significantly predict bedtime and sleep quality. Furthermore, the RCSM indicated a non-linear relationship pattern between digital activity duration and sleep quality, with a weekly peak point of 25 h. Age significantly moderated the relationship between digital activity, sleep duration and bedtime. Younger youth who used digital media more frequently and for a longer time tended to sleep later and had shorter sleep duration than older youth.

CONCLUSION

Digital usage significantly predicted later bedtime among Chinese working youth; however, it was not linked with sleep duration on workdays or free days. In parallel, a nonlinear correlation between digital activity duration and sleep quality indicated that appropriate digital activity duration (less than 25 h weekly) may contribute to good sleep quality.