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Study Objectives: This study investigated the altered neural function involved in emotional interference and its role in linking sleep disturbance and depressive/anxiety symptoms in rotating shift workers., Methods: Sixty rotating shift workers and 61 controls performed the emotional Stroop task in three blocks (emotional-related, sleep-related, and neutral words) during functional magnetic resonance imaging (fMRI) assessments. Sleep disturbance and depressive/anxiety symptoms were assessed using self-report measures and sleep diaries. Actigraphy was used to assess the sleep and circadian variables. fMRI scans were performed to compare brain activation during the emotional Stroop task. The proposed moderating models were tested using the PROCESS macro in SPSS software., Results: A significant condition effect on reaction time was detected. Regardless of the group, reaction times were longer in the negative emotional word and sleep-related conditions than in the neutral word condition. Whole-brain analysis revealed that rotating shift workers show greater neural activation in the left dorsolateral prefrontal cortex (DLPFC) compared with controls while performing the emotional Stroop task with negative emotional words. Sleep disturbance was more strongly associated with depressive symptoms when activation of the left DLPFC was higher during the emotional Stroop task with negative words., Conclusions: The left DLPFC may play important roles in increased sensitivity to emotional information, possibly due to circadian misalignment, and has moderating effects on the association between sleep disturbance and depressive symptoms in rotating shift workers. These findings will help to identify possible brain regions where interventions can be performed to correct sleep and mood problems in rotating shift workers., (© The Author(s) 2022. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

We investigated differences in brain activity in response to sleep-related pictures between chronic insomnia disorder (CID) patients and good sleepers (GS), and examined whether brain activity moderated the relationship between depressive symptoms and sleep disturbance in CID patients and GS. This study included 43 patients diagnosed with CID, based on the International Classification of Sleep Disorders-3, and 42 GS. The participants kept a sleep diary, underwent nocturnal polysomnography to measure sleep parameters, and completed self-report questionnaires to assess sleep and psychiatric symptoms. They underwent functional magnetic resonance imaging (fMRI) to examine differences in brain activity in response to sleep-related pictures compared to neutral pictures. A moderated moderation analysis was performed to investigate the moderating role of brain responses to sleep-related pictures in the association between depressive symptoms and sleep disturbance. Compared to GS, the brain responses to sleep-related stimuli were significantly lower in CID patients in the right lateral prefrontal cortex (LPFC) and dorsomedial prefrontal cortex (DMPFC). More severe depressive symptoms were significantly associated with longer sleep latency only when LPFC activity was low in CID patients, but not in GS. LPFC hypoactivity in response to sleep-related stimuli in CID patients could moderate the relationship between depression and sleep disturbance., (© 2022. The Author(s).)

Objectives: Evidence suggests that emotion regulation difficulty may play an important role in the association between life stress, sleep disturbance and depressive symptoms. We proposed two models depicting the possible moderating roles of prefrontal cortex activation during emotion regulation in the associations among these variables and tested them. We hypothesized that (1) the association between stress and sleep disturbance would differ across prefrontal cortex activation during emotion regulation (moderation model) and (2) the indirect effects of stress on depressive symptoms through sleep disturbance would depend on prefrontal cortex activation during emotion regulation (moderated mediation model)., Methods: Forty-eight healthy adults without sleep disorders based on nocturnal polysomnography participated in this study. They received functional magnetic resonance imaging scans while performing an emotion regulation task. They also completed questionnaires assessing life stress, sleep disturbance and depressive symptoms. The proposed models were tested using the PROCESS macro for SPSS., Results: As hypothesized, there was a significant moderating effect of prefrontal cortex activation during emotion regulation on the association between life stress and sleep disturbance. Furthermore, right lateral prefrontal cortex activation had a moderating role in the indirect effect of life stress on depressive symptoms through sleep disturbance., Conclusion: These findings highlight the important role of prefrontal cortex function during emotion regulation in the associations between stress, sleep disturbance and depressive symptoms. Increasing lateral prefrontal cortex recruitment when regulating the emotional response to negative life events may be critical for the prevention and intervention of depression as well as sleep problems.

Background: This study investigated the effects of anterior insula (AI) activation on the association between stress and sleep disturbance as a neurobiological basis of the trait-like degree of sleep reactivity to stress. Additionally, it examined the effects of AI activity on the association between sleep disturbance and depression., Methods: The participants were 48 adults. To assess AI activation in response to sleep-related stimuli (SS) compared to neutral stimuli (NS), we extracted mean AI parameter estimates for the SS-NS contrast. We examined whether the interaction between life stress and AI activation would predict sleep disturbance and whether the interaction between sleep disturbance and AI activation would predict depression., Results: At higher levels of bilateral AI activation in response to SS, higher levels of stress were associated with greater sleep disturbance (left AI x stress: b = 1.07, SE = 0.44, p < 0.05; right AI x stress: b = 1.05, SE = 0.48, p < 0.05). In addition, at higher levels of right AI activation, higher levels of sleep disturbance were associated with more severe depressive symptoms (right AI x sleep disturbance: b = 2.55, SE = 1.10, p < 0.05)., Limitation: This study assessed sleep quality and depressive symptoms based on self-reported questionnaires., Conclusion: This study revealed moderating effects of AI activation on the association between negative life stress and sleep disturbance. Additionally, AI activation strengthened the association between sleep disturbance and depression. AI activation may reflect a crucial etiological diathesis for insomnia and stress-related disorders., (Copyright © 2021. Published by Elsevier B.V.)