Effects of Presleep Cognitive Intrusions on Subjective Sleep and Next-Day Cognitive Performance in Insomnia

The relationships among metacognitive functions, sleep-related thought-control strategies and sleep quality: A mediation analysis

In the context of sleep disturbances, increasing evidence suggests a critical role of sleep-related dysfunctional metacognitive activity, including metacognitive control of intrusive thoughts in the pre-sleep period. Although the relationship between sleep-related thought-control strategies and poor sleep quality is well recognized, the possible contribution of general metacognitive functioning within this relation is still unclear. In this study, we performed a mediation analysis to examine the role of thought-control strategies on the relationship between metacognitive abilities and sleep quality in individuals with different self-reported sleep characteristics. Two-hundred and forty-five individuals participated in the study. Participants completed the Pittsburgh Sleep Quality Index, the Thought Control Questionnaire Insomnia-Revised, and the Metacognition Self-Assessment Scale to evaluate sleep quality, thought-control strategies and metacognitive functions, respectively. The results showed that worry strategy in the pre-sleep period mediates the relationship between metacognitive functions and sleep quality. Particularly, the ability to understand one's mental states and mastery functions could be the two metacognitive domains primarily involved in the dysfunctional metacognitive thought-control activity responsible for reduced sleep quality. The observed effect suggests that inadequate metacognitive functioning is associated with poor sleep quality in healthy subjects via the mediation of dysfunctional worry strategy. These findings suggest the potential relevance of clinical interventions to enhance specific metacognitive abilities, with the aim to promote more functional strategies for managing cognitive and emotional processes during the pre-sleep period.

Perseverative Cognition and Psychotic-Like Experiences in Young Adults: A Cross-Lagged Panel Model

Psychotic-like experiences (PLEs), including persecutory ideation, bizarre experiences, and perceptual abnormalities, are considered risk factors for psychotic disorders and mental distress in the general population. The cognitive-affective mechanisms associated with PLEs remain under-investigated. We aimed to longitudinally assess the reciprocal associations between perseverative cognition (PC), an emerging transdiagnostic factor of psychopathology, and PLEs facets in young adults. Participants (n = 160) from the general population completed measures of PC and PLEs at baseline and at 2-month follow-up. A two-wave, three-variable, cross-lagged panel model was implemented controlling for well-established correlates of PC and PLEs such as depression, anxiety, and symptoms of sleep disturbance. Both PLEs and PC exhibited substantive rank-order stability (β ranged from 0.359 to 0.657, ps < 0.001). Cross-lagged effects revealed that baseline PC was associated with bizarre experiences at 2-month follow-up (β = 0.317; p < 0.01). This effect overcame the well-established cut-off for practical significance. In contrast, no baseline PLEs were associated with PC at follow-up. Findings suggest the presence of a monodirectional, rather than bidirectional, association between PC and bizarre experiences in young adulthood. Results should be interpreted in light of the relatively small, non-clinical, and convenient sample.

Peripheral brain-derived neurotrophic factor (BDNF) in insomnia: A systematic review and meta-analysis

The brain-derived neurotrophic factor (BDNF) is associated with emotional and cognitive functioning, and it is considered a transdiagnostic biomarker for mental disorders. Literature on insomnia related BDNF changes yielded contrasting results and it has never been synthetized using meta-analysis. To fill this gap, we conducted a systematic review and meta-analysis of case-control studies examining the levels of peripheric BDNF in individuals with insomnia and healthy controls using the PRISMA guidelines. PubMed, Scopus, Medline, PsycINFO and CINAHL were searched up to Nov 2022. Nine studies met the inclusion criteria and were assessed using the Newcastle-Ottawa Scale. Eight studies reported sufficient data for meta-analysis. Random-effects models showed lower BDNF in subjects with insomnia (n = 446) than in controls (n = 706) (Hedge's g = -0.86, 95% CI: -1.39 to -0.32, p = .002). Leave-one-out sensitivity analysis confirmed that the pooled effect size was robust and not driven by any single study. However, given the small sample size, the cross-sectional nature of the measurement, and the high heterogeneity of included data, the results should be cautiously interpreted. Progress in the study of BDNF in insomnia is clinically relevant to better understand the mechanisms that may explain the relationship between disturbed sleep and mental disorders.

Perseverative Cognition as a Mediator Between Perceived Stress and Sleep Disturbance: A Structural Equation Modeling Meta-analysis (meta-SEM)

Background

According to the perseverative cognition (PC) hypothesis, the repetitive chronic activation of the cognitive representations of stressors are associated with a concomitant prolonged and sustained physiological stress response, including sleep disruption.

Purpose

We conducted a systematic review and structural equation modeling meta-analysis (meta-SEM) on PC as mediator of the association between perceived stress and subjective sleep disturbance (i.e., difficulties falling asleep or maintaining sleep).

Methods

PubMed, Scopus, Medline, CINAHL, and PsycInfo were searched up to September 2021. To test mediation, only longitudinal studies assessing the predictor (perceived stress) at T0, the mediator (PC) at T1, and the outcome (sleep disturbance) at T2, were eligible.

Results

Findings on 3,733 individuals (k = 8) showed a significant component effect of perceived stress on PC (β = 0.340, p &lt; .001), which in turn was related to sleep disturbance (β = 0.258, p &lt; .001). The direct effect of stress on sleep disturbance was significant (β = 0.133, p &lt; .001). Lastly, the indirect effect between stress and sleep disturbance via PC supported the mediation hypothesis (β = 0.09, 95% CI 0.078–0.100). The mediation path remained significant (β = 0.03, 95% CI 0.020–0.036) after adjusting for baseline sleep disturbance. Further leave-one-out sensitivity and control analyses confirmed that all direct and indirect effects were not driven by any single study included in the meta-analysis, as well as their robustness when controlling for sex and age, respectively.

Conclusions

Overall, results of this meta-analysis indicate that PC may be one of the mechanisms explaining how perceived stressful experiences lead to subjective sleep disturbance.

Sleep well, mind wander less: A systematic review of the relationship between sleep outcomes and spontaneous cognition

Despite an upsurge of research on spontaneous cognition, little is known about its associations with sleep-related outcomes. This systematic review, following PRISMA guidelines, examined the relationship between sleep and spontaneous thoughts, across different definitions and measurements of sleep outcomes and spontaneous cognition, and a diversity of methodologies. Twenty-one articles with survey and/or experimental designs were identified. Self-reported disturbed sleep-comprising poor sleep quality, more insomnia symptoms, more daytime sleepiness and a tendency towards eveningness-and experimentally induced sleep deprivation were associated with a tendency to engage in disruptive mind wandering and daydreaming, but not positive-constructive daydreaming. Findings regarding circadian fluctuation in spontaneous thoughts were mixed and inconclusive. This systematic review bridges the gap between the sleep and spontaneous cognition research by contributing to the understanding of potential psychological and cognitive mechanisms of spontaneous cognition, as well as by elucidating the emotional and cognitive consequences of disturbed sleep.

The Interplay Between Problematic Online Pornography Use, Psychological Stress, Emotion Dysregulation and Insomnia Symptoms During the COVID-19 Pandemic: A Mediation Analysis

PURPOSE

Although a link between problematic online pornographic use (POPU) and insomnia symptoms has been established, psychological and psychopathological mechanisms underlying this relationship are still not clear. Psychological stress and emotion dysregulation have been pointed out as relevant in the development and maintenance of insomnia. This study aims to explore the associations between POPU, psychological stress, emotion dysregulation and insomnia symptoms and to understand the mediating role of psychological stress and emotion dysregulation in the relationship between POPU and insomnia symptoms.

PARTICIPANTS AND METHODS

A sample of 776 Italian adults aged 19-48 years (51.4% female; M age = 28.49; SD = 7.33) completed questionnaires regarding demographics, COVID-19-related variables, POPU, psychological stress, emotion dysregulation, and insomnia symptoms.

RESULTS

After controlling for demographic covariates and COVID-19-related variables, multiple mediation model showed that higher psychological stress and emotion dysregulation fully mediated the link between POPU and insomnia.

CONCLUSION

The findings underscore the significance of the negative consequences of POPU and underline the importance of working on this and its effects on psychological stress and emotion dysregulation to limit insomnia.

Bedtime repetitive negative thinking moderates the relationship between psychological stress and insomnia

Research suggests that psychological stress is associated with insomnia, but there is limited research on vulnerabilities that might amplify this association, particularly in college students. Based on a sample of 507 undergraduates, the current study demonstrates that the observed positive correlation between self-perceived stress and insomnia severity is moderated by the tendency to engage in repetitive negative thinking (RNT) at bedtime. Additionally, separate analyses of those who scored below/above the threshold for insomnia (non-insomniacs vs. insomniacs) revealed that the interaction between stress and these negative bedtime cognitions differed qualitatively between the two groups. In insomniacs, the stress-insomnia relationship was dampened for those with lower levels of bedtime RNT, but amplified for those with higher levels. For non-insomniacs, the stress-insomnia relationship was stronger for those with minimal bedtime RNT, while higher levels of bedtime RNT appeared to overshadow this association. To develop a better understanding of the contribution of stress and RNT to clinically relevant levels of insomnia, future studies should take into account the dissimilar patterns of moderation seen in non-insomniacs and insomniacs, either through prospective screening or separate analyses. Findings from the current study suggest that insomnia treatments that can simultaneously reduce stress and address bedtime RNT may be optimal.

Insomnia Symptoms Moderate the Relationship Between Perseverative Cognition and Backward Inhibition in the Task-Switching Paradigm

Perseverative cognition (PC), that is, the continuous cognitive representation of uncontrollable threats, is known to dampen executive control processes in experimental paradigms. Similarly, PC has been shown to impair sleep and to be implicated in the exacerbation of insomnia, which may in turn contribute to the disruption of executive functions. The interactions between PC and insomnia in influencing executive functions, however, have never been tested to date. In the present study, we explored whether insomnia symptoms may moderate the associations between PC and disrupted executive functions, with the hypothesis to find a stronger relationship between these variables at increasing levels of insomnia. Fifty participants completed measures of trait PC and insomnia severity in the previous month and also completed a computerized task-switching paradigm assessing backward inhibition, switch cost, and accuracy. Prior to the task switching, participants completed a measure of state rumination in order to control for the effects of state PC on cognitive performance. Results show that trait PC was significantly correlated with higher insomnia symptoms and state rumination and marginally correlated with lower backward inhibition and longer switch cost. Moreover, insomnia severity moderated the relationship between trait PC and backward inhibition after controlling for the effects of state rumination; that is, the relationship between PC and inhibitory deficits was stronger in those with higher versus lower levels of insomnia symptoms. Findings suggest the need to better elucidate the associations between PC, insomnia, and executive functioning in clinical samples and longitudinal designs.

Decreased inhibitory control after partial sleep deprivation in individuals reporting binge eating: preliminary findings

Background

Poor executive functions are associated with dysregulated eating and greater caloric intake in healthy samples. In parallel, findings suggested that sleep deprivation impairs executive functions.

Methods

We investigated whether partial sleep deprivation impairs executive functions in individuals reporting binge eating (BE, N = 14) and healthy controls (C, N = 13). Switch cost and backward inhibition were measured using the Task Switching Paradigm after a habitual night of sleep and after a night of partial sleep deprivation.

Results

Results showed a Night by Group interaction on the backward inhibition. The two groups differed in the habitual night, evidencing higher inhibitory control in BE compared to C. Additionally, after partial sleep deprivation, compared to the habitual night, backward inhibition decreased in BE group. This preliminary study was the first to explore the impact of sleep deprivation on executive functions in participants reporting binge eating and healthy controls, thus highlighting their potential role in influencing eating behavior.