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The cognitive ability to self-monitor one’s current performance is important for hospital nurses to maintain safety and health. However, studies on the effects of rotating shift work on self-monitoring ability are insufficient. We examined the differences in self-monitoring accuracy across shifts in a rotating three-shift system among 30 female ward nurses (mean age 28.2 years). Their self-monitoring ability was calculated by subtracting the predicted reaction times of the psychomotor vigilance task performed just before exiting the workplace from the actual reaction times. A mixed-effect model was employed to assess the effects of shift, awake hours, and prior sleep duration on self-monitoring ability. We observed impaired self-monitoring ability in nurses, particularly after the night shift. Although actual performance remained high across all shifts, their self-predictions on reaction times became pessimistic in the night shift, resulting in a difference of approximately−100 msec. The effect of the shift on self-monitoring was obvious even after adjusting for sleep duration and hours awake. Our findings indicate that the misalignment between their working hours and circadian rhythms may affect even professional nurses. Occupational management that emphasizes maintaining circadian rhythms will improve the safety and health of nurses.

This study examined the characteristics of occupational mental disorders among those involved in the transport and postal activities in the trucking industry.We examined 237 out of 3,517 cases of occupational mental disorders, compensated between the fiscal years 2010 and 2017. An assessment was made for sex, "life-or-death" status at compensation, age at the onset and suicide, the diagnosis according to the International Classification of Diseases, Tenth Revision, and other factors regarding occupational compensation. The participants were divided into two groups: truck drivers and non-truck drivers.Men accounted for approximately 90% of the cases. Depressive episode (F32) was the most common diagnosis in drivers and non-drivers, thus constituting 65 out of 149 and 48 out of 88 cases, respectively. The next most common type of mental disorder was adjustment disorders (F43.2), with 34 out of 149 drivers and 24 out of 88 non-drivers reporting them. Furthermore, the majority of drivers that had posttraumatic stress disorder (24 out of 27 cases) reported that they "suffered a serious illness or injury" and "experienced or witnessed a terrible accident or disaster." Occupational disasters due to long working hours were 52.4% for drivers and 73.9% for non-drivers. A total of 30.8% of the drivers reported working long hours since they joined the company.Drivers' long working hours entail waiting at the origin and cargo destination site, handling cargo, and incidental tasks other than driving. Thus, the reduction in work hours regarding these tasks needs to be a fundamental goal, and measures that include mental health care for accidents and miserable experiences must be implemented. However, long working hours for non-drivers are likely linked to job expansion/increase and reassignment/relocation. These findings highlight that to prevent overwork-related mental disorders, appropriate actions should be taken considering different sources of exposure for drivers or non-drivers.

Childhood maltreatment has been associated with increased inflammation, as indicated by elevated levels of proinflammatory markers such as interleukin-6 (IL-6) and C-reactive protein (CRP). Studies in humans show that secretion of IL-6 follows a clear circadian rhythm, implying that its disturbed rhythm represents an important aspect of dysregulated inflammatory system. However, possible alterations in diurnal secretion patterns of IL-6 associated with childhood maltreatment have not been studied. Here we investigated this association in 116 healthy adults. Diurnal levels of IL-6 were examined using saliva samples collected at 5 times a day across 2 consecutive days. Salivary CRP levels were also determined by averaging measurements at 2 times a day for 2 days. Different types of childhood maltreatment were assessed with the Childhood Trauma Questionnaire (CTQ). CTQ total and emotional abuse scores were significantly correlated with smaller IL-6 diurnal variation as indexed by lower standard deviation across the measurement times (p = 0.024 and p = 0.008, respectively). Individuals with emotional abuse, as defined by a cut-off score of CTQ, showed flatter IL-6 rhythm than those without (p = 0.031). These results, both correlation and group comparison, remained significant after controlling for age, sex, and body mass index. Childhood maltreatment was not associated with total output of IL-6 or CRP. Our findings indicate that childhood trauma can have a long-term negative effect on the circadian rhythm of inflammatory system. The findings are consistent with those of previous studies on adulthood trauma, suggesting that the disrupted IL-6 rhythmicity may be associated with a broad range of trauma-related conditions.

This study examined the effects of short sleep duration (SSD) on hemodynamic and psychological responses under long working hours (LWH) in a laboratory experiment. Sixteen subjects participated in a crossover design experiment consisting of two conditions: normal (7-hours) sleep and short (5-hours) sleep. In each condition, participants engaged in simulated LWH (13 hours a day), comprising 12 task sessions. Hemodynamic and psychological responses were measured in each session. Results showed that there were significant main effects of condition and session but no interaction for hemodynamic and psychological responses. Systolic blood pressure and fatigue were higher in the later sessions than the first one. Stroke volume, sleepiness, fatigue, and stress were higher in the 5-hour than the 7-hour sleep condition (all p0.05). These results suggest that although the combined effect of LWH and SSD was not significant, both LWH and SSD caused a hemodynamic and psychological burden.

The aim of the study was to examine the relationship between sleep problems and objective driving behaviors of short-haul commercial truck drivers in Japan. One hundred and ten male short-haul commercial truck drivers’ sleep duration, sleep quality (Pittsburgh Sleep Quality Index), and frequency of sleepiness at the wheel were measured by survey in June 2019. In addition, their dangerous driving behaviors (i.e., overspeeding, sudden start and acceleration, sudden deceleration, and sudden braking) during June were calculated using digital tachograph data. Logistic regression analysis (LRA) was performed. The dependent variables were the presence/absence of dangerous driving behaviors, and sleep duration, sleep quality, and sleepiness were assigned as independent variables. Body mass index was adjusted as a confounding variable. LRA for sleep duration revealed that the “

Purpose We aimed to cross-sectionally investigate how work and sleep conditions could be associated with excessive fatigue symptoms as an early sign of Karoshi (overwork-related cerebrovascular and cardiovascular diseases; CCVDs). Methods We distributed a questionnaire regarding work, sleep, and excessive fatigue symptoms to 5410 truck drivers, as the riskiest occupation for overwork-related CCVDs, and collected 1992 total samples (response rate: 36.8%). The research team collected 1564 investigation reports required for compensation for Karoshi. Of them, 190 reports listed the prodromes of Karoshi, which were used to develop the new excessive fatigue symptoms inventory. Results One-way analyses of variance showed that the excessive fatigue symptoms differed significantly by monthly overtime hours (p p p = 0.025), waiting time on-site (p = 0.049), number of night shifts (p = 0.011), and sleep duration on workdays (p Conclusion The findings suggested that shorter sleep duration was associated more closely with a marked increase in fatigue, as compared with the other work and sleep factors. Hence, ensuring sleep opportunities could be targeted for reducing the potential risks of Karoshi among truck drivers.

Background The amygdala can enhance emotional memory encoding as well as anxiogenesis via corticotropin-releasing factor neurons. However, the amygdala’s explicit role in emotional encoding remains unclarified in humans. We examined how functional connectivity (FC) of amygdala subnuclei affects emotional encoding, considering its mechanism in which anxiety, attention, and cortisol conceivably participate. Methods A total of 65 healthy humans underwent resting-state functional magnetic resonance imaging scans and saliva collection at 10 points in time over 2 days. FC analysis was performed for basolateral amygdala subnucleus (BLA) and centromedial amygdala subnucleus. We assessed attentional control via an emotional Stroop task and assessed emotional encoding via a facial identification task that examines how strongly a neutral face is memorized when accompanied by an emotional face (fearful, sad, or happy). FC and task performance were compared between high-anxious and non-high-anxious groups classified by anxious personality scores. Results BLA connected with subgenual anterior cingulate cortex (sgACC) in proportion to the strength of fear-related encoding, whereas centromedial subnucleus connected with caudate nucleus for happy-related encoding. The high-anxious group showed more enhanced fear-related encoding but impaired happy-related encoding compared with the non-high-anxious group. BLA–sgACC FC was more intensified in the high-anxious group than in the non-high-anxious group; however, centromedial–caudate FC did not differ between them. Although emotional encoding was uncorrelated with either attentional control or cortisol, BLA–sgACC was positively correlated with cortisol increase after awakening. Conclusions The study revealed that neural interactions of BLA, specifically with sgACC, might play a critical role in fear-related memory encoding, depending on the individual’s level of anxiety. These findings aid in understanding the complicated mechanisms of emotional memory in anxiety disorders.

During the Coronavirus disease 2019 (COVID-19) pandemic, social isolation and impaired social interaction could be the factors that cause mental health problems. This study investigated the association between conversation time in daily life and mental health among Japanese employees.In August 2021, a web-based cross-sectional survey was conducted with 1000 Japanese employees. Weekly conversation time was assessed in four domains (family members, friends, someone in the workplace, and others), and mental health was assessed using the Japanese version of the Kessler Psychological Distress Scale (K6 scale). Weekly total conversation time was calculated, and participants were assigned to one of the four conversation time categories based on quantile values to investigate the associations with poor mental health (K6 ≥ 13).The logistic regression analyses revealed that participants with short conversation times (3.5 h per week) had poorer mental health compared to those with long conversation times ( 21.0 h per week), even after adjusting for confounders (OR = 2.48 [95% CI 1.31-4.71]). For the exploratory analyses of conversation time for each domain, the associations of short conversation time in the workplace with poor mental health was most robust (OR =2.02 [95% CI 1.13-3.63]).Japanese employees with conversation time of3.5 h per week (i.e., 30 min per day) had poor mental health. During the COVID-19 pandemic, people have largely limited opportunities to have conversations with others, but a certain level of conversation time might be required to maintain mental health.

Social evaluative threat activates the HPA-axis system, namely cortisol and dehydroepiandrosterone (DHEA) responses. Additionally, cognitive and behavioral models in social anxiety, which is aroused anxiety symptoms in social situations, indicate that negative cognitions have a role in the maintenance of symptoms. Thus, the present study examined the relationship between HPA-axis activity and cognitive features in social situations. We conducted the Trier Social Stress Test (TSST) with 44 male participants and assessed HPA-axis responses, fear of negative evaluation, the estimated social cost, and self-perceptions of their speech performance, which are core negative cognitions in social situations. Results revealed that the cortisol-DHEA ratio significantly correlated with self-perceptions of participants’ speech performance (r = .30, p = .044) and the discrepancy between self-ratings and others’ ratings of the speech (r = .44, p = .003). After controlling for depressive symptoms, significant correlations remained (r = .39, p = .01 and r = .50, p = .001, respectively). In addition, the estimated social cost, assessed before the speech task, significantly correlated with both the AUCg cortisol (r = .38, p = .011) and cortisol-DHEA ratios (r = .40, p = .007). These results suggest that estimating social costs in social situations, as well as distorted self-perceptions of that stressor, is related to dysfunctional endocrine regulation.

Cortisol levels in hair and fingernail samples could represent hormone levels that have accumulated over the past weeks and months. In this study, by using retrospective indexes, the associations between cortisol and the onset of acute coronary syndrome (ACS) were investigated among middle-aged and elderly men. We measured hair/fingernail cortisol levels in 73 ACS patients and 93 healthy controls; hair and fingernail samples for ACS patients were collected within a few weeks after the onset of ACS. The results indicated the patients exhibited significantly higher cortisol levels in their hair and fingernails compared with the healthy controls. In multivariate logistic regression analyses, adjusting for the traditional cardiovascular risk factors for ACS, high levels of hair or fingernail cortisol were associated with two- to three-fold increased risk of ACS, compared with low levels. We demonstrated that cortisol exposure over a relatively long period, assessed by hair and fingernail samples, was associated with the onset of ACS.

More knowledge is required to determine the optimal shiftwork schedule to reduce the harmful effects of short restart breaks between shifts. This 5-month intervention study aimed to examine the effectiveness of extended restart breaks from 31 h to 55 h after consecutive night shifts by considering the characteristics of the circadian rhythm to mitigate fatigue and sleep among 30 shift-working nurses. Subjective and objective variables, such as vital exhaustion, distress, hair cortisol, salivary C-reactive protein, and sleep mattress sensor sensation, were repeatedly measured to examine the differences between the intervention and control conditions. Two-way (condition × time) multilevel analyses showed significantly lower levels of vital exhaustion and distress in the intervention condition (p = 0.005 and p = 0.004, respectively). However, the expected benefit of the intervention was not observed in objectively measured variables. These findings suggested that an extended restart break after consecutive night shifts can moderately decrease occupational fatigue and stress.

A daily rest period (DRP) is a daily inter-work interval that contains sleep opportunity. This study investigates the joint association of DRP and sleep duration with worker health and productivity. A total of 13,306 Japanese daytime workers participated in this web-based cross-sectional survey. Participants reported on their DRPs and sleep duration; moreover, sleep difficulties, mental health, and presenteeism were assessed by the standardized questionnaires. The participants were divided into 10 groups based on their DRPs and sleep duration. Logistic regression analyses showed that the combination of quick return (QR: DRP of

OBJECTIVES Karoshi problems (overwork-related deaths and disorders caused by cerebrovascular and cardiovascular diseases) still occur in Japan. Truck drivers, who are in one of the riskiest occupations, are reported to show an increased prevalence of hypertension, obesity, hyperlipidemia, and diabetes, which are characteristic of Karoshi. Their health problems also include excessive fatigue. This cross-sectional study aimed to examine the association between work-life factors and health disorders/excessive fatigue among Japanese truck drivers. METHODS We distributed a questionnaire regarding work hours, health status, lifestyle, burden of driving, and excessive fatigue to 5,410 truck drivers and collected a total of 1,947 responses, all from males. The association between work-life factors and health outcomes was evaluated by multivariable logistic regression analysis adjusted for age, drinking, and smoking status. RESULTS The prevalence rates of obesity, hypertension, hyperlipidemia, diabetes, cardiovascular disease, cerebrovascular disease, and excessive fatigue were 22.2%, 19.3%, 8.5%, 5.6%, 2.5%, 0.7%, and 6.0%, respectively. Significant associations were observed for long-haul trips (two days or more) with obesity (adjusted odds ratio 1.5 [95% Confidence Interval 1.1-2.1]), local and night trips with hypertension (1.5 [1.0-2.2]), early morning awakening on workdays with obesity (1.5 [1.1-2.1]), being indoor-oriented on weekends with hypertension (1.5 [1.1-2.0]); and heavy burden of driving at night with hyperlipidemia (2.0 [1.3-3.0]). The adjusted odds ratios were significant for waking after sleep onset (2.6 [1.2-5.3]) and lack of sleep satisfaction (2.7 [1.4-5.1]) on workdays, less than six hours of sleep (2.8 [1.0-7.8]) and lack of sleep satisfaction (2.8 [1.5-5.2]) on weekends, 0-3 days off per month (3.6 [1.3-10.2]), and heavy burden of driving at night (2.2 [1.0-4.8]) with excessive fatigue. CONCLUSIONS The present findings highlight that night and early morning work, heavy burden of night driving, and the resultant decreases in the quality and quantity of sleep may represent shared risk factors for health disorders and excessive fatigue among truck drivers. Adequate measures should be taken to limit the amount of night and early morning work, reduce the burden of night driving, and ensure days off for sleep opportunities and leisure activities, with the goal of preventing Karoshi.

Background Psychological trauma can damage the brain, especially in areas where glucocorticoid receptors are expressed, via perturbed secretion of cortisol. Childhood trauma is associated with blunted basal cortisol secretion, brain alterations, and autobiographical memory deficits referred to as overgeneral autobiographical memory (OGM). However, it remains unknown whether childhood trauma affects OGM through altered cortisol and brain alterations. Methods Using resting-state fMRI in 100 healthy humans, we examined whether childhood trauma affects OGM through its related basal cortisol and brain functional connectivity (FC). Trauma and OGM were assessed using the Childhood Trauma Questionnaire (CTQ) and Autobiographical Memory Test (AMT), respectively. Basal cortisol levels were measured by 10 points-in-time across two days. Multiple mediation analysis was employed. Results CTQ was associated with greater semantic-associate memory of OGM, a retrieval tendency toward semantic content with no specific contextual details of an experienced event, as well as blunted basal cortisol levels. While CTQ was correlated with decreased FC between the hippocampus and medial prefrontal cortex (PFC), it showed a more predominant correlation with increased FC between the lateral and anteromedial PFC and extrastriate cortex. Importantly, the increased prefrontal-extrastriate FC completely mediated the relationship between CTQ and semantic-associate memory, affected by hyposecretion of cortisol. Conclusion Childhood trauma may lead to the lack of visuoperceptual contextual details in autobiographical memory by altering basal cortisol secretion and connectivity of the prefrontal-hippocampal-extrastriate regions. The intensified prefrontal-extrastriate connectivity may contribute to OGM formation by strengthening the semantic content in memory retrieval. Understanding the mechanisms underlying the trauma-cortisol-brain-memory link will provide important clinical implications for trauma-related mental disorders.

Background: The European Union's Working Time Directive stipulates recovery periods as "Eleven consecutive hour daily rest periods (DRPs) between working days." In Japan, adopting this regulation has been discussed. Objective: To examine the association between weekday DRPs and recovery from fatigue by conducting a one-month observational study using a fatigue monitoring application (fatigue app) on a smart tablet. Methods: Fifty-five daytime employees working at an information technology company participated in this study. Visual analogue scales (VAS) regarding fatigue, psychological detachment from work, a psychomotor vigilance task (PVT), and sleep-wake logs were repeatedly measured using a fatigue app that we developed for this study. Sleep was measured by a wrist actigraph. Results: The average and SD of weekday DRPs was 13.1 ± 2.3 h. However, 54.5% of employees experienced less than the minimum 11-hour DRP at least once a month. Sleep duration was significantly changed with weekday DRPs, though no significant difference was found in sleep efficiency. Linear mixed effects models showed that sleep duration increased by approximately 15 minutes for each hour of weekday DRPs (β = 0.24, 95% CI; 0.17, 0.32, p

Anxiety and depression are linked to both explicit and implicit memory biases, which are defined as the tendency to preferentially recall emotionally negative information at conscious and subconscious levels, respectively. Functional connectivity (FC) of the basolateral amygdala (BLA) and related stress hormones (i.e., cortisol and norepinephrine) are purportedly implicated in these biases. However, previous findings on memory biases in anxiety and depression have been inconsistent, likely due to their symptomatic complications. Therefore, the underlying neurobiological mechanism remains unclear. We thus investigated whether anxiety and depression as premorbid predispositions are related to the memory biases, and whether FC of BLA, cortisol, and 3-methoxy-4-hydroxyphenylglycol (MHPG: a major metabolite of norepinephrine) would affect the anxiety/depression-related biased memory recall in 100 participants without psychiatric symptomatology. Psycho-behavioral assessment, resting-state fMRI scans, and saliva collection at 10-points-in-time across two days were conducted. Correlations of memory biases with anxiety/depression and neurobiological markers were explored. As a result, neither anxiety nor depression were correlated with explicit memory bias to negative (vs. positive) information, although depression was associated with better recall of the negative stimuli only when they were perceived as self-relevant. In contrast, both anxiety and depression were correlated with implicit memory bias; however, the effects were solely explained by anxiety. Furthermore, FC of the BLA with subgenual anterior cingulate cortex (sgACC) and the synergetic effect of cortisol and MHPG uniquely affected the implicit memory bias. These findings suggest that anxiety facilitates an initial snapshot of negative information and can be accompanied by depression when the information creates negative semantic associations with the self. The BLA-sgACC neural connectivity and cortisol-norepinephrine interaction that are associated with the implicit memory bias might be one of the important neurobiological targets in the prevention and treatment for comorbid anxiety and depressive disorders.

This study aimed to validate the association between hair cortisol and 30-day integrated salivary cortisol levels. Additionally, the intra-individual stability of the hair cortisol and the association between hair cortisol and salivary cortisol in several time domains were systematically explored. Twenty-four adults (15 men and 9 women, mean age: 22.7 ± 2.8 years) were asked to collect three saliva samples per day for 30 days, immediately after awakening (time 1), 30 min after awakening (time 2), and at bedtime (time 3). The hair sample was taken from the posterior vertex as close as possible to the scalp at the end of the 30-day study period. The area under the curve based on times 1 and 3 showed that cortisol levels in the 1 cm hair segment closest to the scalp were moderately correlated with the 30-day salivary cortisol levels (r = 0.41, p = 0.047). However, this correlation was not observed for the cortisol awakening response, diurnal slope, or other metrics in different time domains. The mean salivary cortisol at time 3 was significantly correlated with hair cortisol (r = 0.42, p = 0.041). Intra-individual stability of the hair cortisol was maintained for at least 4 months. Hair cortisol may reflect basal cortisol levels more substantially over longer periods (longer than 1 month and for at least 4 month), thus reflecting longitudinal cortisol production, rather than the day-to-day temporal cortisol response. Salivary cortisol is an ideal metric for short-term or day-to-day stress response. Researchers should select suitable metrics, such as hair cortisol for basal level (or trait) or salivary cortisol for response (or state), depending on the study objective.

A daily rest period (DRP; rest taken from daily work during a 24 h period), is essential to work recovery. This study examined DRPs’ distribution and association with health outcomes among information technology workers recruited from an internet panel (N=1,811). Participants completed a web questionnaire examining psychological distress as a primary outcome, along with non-restorative sleep, fatigue (stress reaction), and work performance. Logistic regression analysis showed elevated psychological distress when DRP was

Accumulating evidence shows that effort–reward imbalance (ERI) at work can cause various health problems. However, few studies have investigated the biological pathways linking ERI and health outcomes, and their findings have been inconsistent. In this study, we investigated the associations between ERI, the hypothalamic–pituitary–adrenocortical axis, and inflammation in a sample of police officers. One hundred forty-two male police officers that were engaged in a working system of 24-h shifts were followed up during the work shift as well as during the two subsequent work-free days. Throughout this period, the participants provided two saliva samples each day for the 3-day period, and we measured the concentrations of cortisol and C-reactive protein (CRP) in the saliva. The police officers also completed the Japanese short version of the Effort–Reward Imbalance Questionnaire. The results of linear mixed model analyses controlled for possible confounding variables indicated that higher effort scores (p = 0.031) as well as effort–reward ratio (p = 0.080) were associated with lower cortisol levels, and the effect of effort was strengthened in the younger police officers (p = 0.017). Furthermore, higher effort scores were associated with higher CRP levels in younger police officers (p = 0.037). Our results indicate that effort, a component of ERI, has physiological effects in younger police officers, which possibly contribute to the development of stress-related diseases.

Being appropriately aware of the extent of stress experienced in daily life is essential in motivating stress management behaviours. Excessive stress underestimation obstructs this process, which is expected to exert adverse effects on health. We prospectively examined associations between stress underestimation and mental health outcomes in Japanese workers. Web-based surveys were conducted twice with an interval of 1 year on 2359 Japanese male workers. Participants were asked to complete survey items concerning stress underestimation, depressive symptoms, sickness absence, and antidepressant use. Multiple logistic regression analysis revealed that high baseline levels of ‘overgeneralization of stress’ and ‘insensitivity to stress’ were significantly associated with new-onset depressive symptoms (OR = 2.66 [95 % CI, 1.54–4.59], p

Introduction Attentional bias modification (ABM) alleviates anxiety by moderating biased attentional processing toward threat; however, its neural mechanisms remain unclear. We examined how ABM changes functional connectivity (FC) and functional network measures, leading to anxiety reduction. Methods Fifty-four healthy anxious individuals received either ABM or sham training for 1 month in a double-blind randomized controlled trial. Anxious traits, attentional control, and attentional bias were assessed. Thirty-five participants completed resting-state functional magnetic resonance imaging (MRI) scans before and after training. Results ABM significantly mitigated an anxious traits regarding physical stress vulnerability (η2 = 0.12, p = 0.009). As compared to sham training, ABM significantly strengthened FC between the pulvinar and transverse temporal gyrus along the temporoparietal junction (T = 3.90, FDR-corrected p = 0.010), whereas it decreased FC between the postCG and ventral fronto-parietal network (vFPN) regions such as the anterior insula and ventrolateral prefrontal cortex (all T ≤ − 3.19, FDR-corrected p ≤ 0.034). Although ABM diminished network measures of the postcentral gyrus (postCG) (all T ≤ − 4.30, FDR-corrected p ≤ 0.006), only the pulvinar-related FC increase was specifically correlated with anxiety reduction (r = − 0.46, p = 0.007). Limitations Per-protocol analysis and reduced sample size in MRI analysis. Conclusions ABM might augment the pulvinar's control over vFPN to maintain endogenous attention to a behavioral goal, while diminishing the information exchanges of the postCG with vFPN to inhibit the capture of exogenous attention by potential threats. The pulvinar might play a critical role in ABM anxiolytic efficacy.

The amygdala plays a critical role in emotion. Its functional coupling with the hippocampus and ventromedial prefrontal cortex extending to a portion of the anterior cingulate cortex (ACC) is implicated in anxiogenesis and hypothalamic-pituitary-adrenal (HPA) system regulation. However, it remains unclear how amygdala-centred functional connectivity (FC) affects anxiety and cortisol concentrations in everyday life. Here, we investigate the relationship between daily cortisol concentrations (dCOR) and amygdala-centred FC during emotional processing in forty-one healthy humans. FC analyses revealed that higher dCOR predicted strengthened amygdala-centred FC with the hippocampus and cerebellum, but inhibited FC with the supramarginal gyrus and a perigenual part of the ACC (pgACC) when processing fearful faces (vs. neutral faces). Notably, the strength of amygdala-hippocampus FC mediated the positive relationship between cortisol and anxiety, specifically when the effect of amygdala-pgACC FC, a presumptive neural indicator of emotional control, was taken into account. Individuals with diminished connectivity between the amygdala and pgACC during fear-related processing might be more vulnerable to anxiogenesis as it pertains to greater circulating cortisol levels in everyday life. Individual functional patterns of amygdala-hippocampal-pgACC connectivity might provide a key to understand the complicate link between cortisol and anxiety-related behaviors.

OBJECTIVE We aimed to examine the effects of the daily rest period (DRP) on resting blood pressure (BP) and fatigue and determine the optimal DRP for daytime workers. METHODS Fifty-four daytime employees participated in a 1-month observational study. BP was measured thrice at the workplace. Employees underwent a pre- and post-survey to determine the usual DRP and assess subjective health outcomes. To determine the optimal DRP, DRP criteria were set as 11, 12, 13, and 14 hours. RESULTS Workers with a shorter DRP had high diastolic BP and fatigue. Diastolic BP was higher in the short group than in the long group for the 14-hour DRP criteria alone. CONCLUSIONS Shorter DRP was associated with high diastolic BP. We recommend a longer DRP (≥14 hours) for improving workers' cardiovascular health.

It was recently suggested that cortisol levels in fingernails reflect cumulative hormone exposure over a relatively long period. This exploratory study cross-sectionally investigated the relationships between fingernail cortisol level and psychosocial stress in a sample of middle-aged workers (94 men and 29 women). The participants were asked to grow their fingernails for ∼2 weeks and then provide fingernail samples from every digit by using nail clippers. Further, they completed questionnaires for assessment of exposure to psychosocial stress in the past (stressful life events in the workplace in the previous year; e.g. change to a different line of work) and in the present (job stress and perceived stress). Results of a regression analysis adjusting for the effects of demographic variables showed that experience of stressful life events, but not job stress and perceived stress, was associated with elevated fingernail cortisol level. These findings indicate the potential of fingernail samples to retrospectively reflect individual differences in cortisol levels related to past psychosocial stress.

Levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) may reflect central noradrenergic activity. In this study, we investigated salivary MHPG changes after awakening, and explored their relationships with cortisol and peripheral autonomic activity. The participants were 25 college students. Saliva samples were collected on awakening and 30 min after awakening to determine MHPG and cortisol. Ambulatory electrocardiograms were obtained to assess heart rate, cardiac sympathetic index (CSI), and cardiac vagal index (CVI) before and after awakening. MHPG levels increased significantly during the first 30 min after awakening. Similarly, cortisol, heart rate, and CSI increased during the 30 min after awakening, but changes in MHPG did not correlate with changes in cortisol, heart rate, CSI, and CVI during that period. This study demonstrated that salivary MHPG levels increase after awakening, in common with cortisol, heart rate, and cardiac sympathetic activity.

Cortisol is known to affect visuospatial memory through its major binding site in the brain, the hippocampus. The synchronization of neural activity between the hippocampus, prefrontal cortex (PFC), and visual cortex is presumed to be essential for the formation of visuospatial memory because of their visuospatial learning-dependent neuroplasticity. However, it remains unclear how hippocampal connectivity with the PFC and visual cortex is involved in the relationship between cortisol and visuospatial memory in humans. We thus investigated whether functional connectivity (FC) of the hippocampus, specifically its rostral and caudal subdivisions, mediates the relationship between visuospatial memory and endogenous cortisol. One-hundred sixty-six healthy young adults underwent standard neuropsychological tests to assess visuospatial construction (a complex figure copying test) and retrieval (the corresponding recall test) and collected their saliva at 6-time points across 2 consecutive days for measurement of daily cortisol concentrations (dCOR). Ninety of them received resting-state fMRI scans. Greater dCOR was significantly associated with better figure copying performance, but contrastingly with poorer figure recall. In proportion to dCOR, the rostral hippocampus (rHC) showed significantly increased FC with the PFC (including its dorsolateral and medial parts) and the inferior lateral occipital cortex (iLOC), while the caudal hippocampus had increased FC with the anterior middle temporal cortex. Of the cortisol-related hippocampal connectivity, the rHC-iLOC FC was specifically correlated with figure recall and showed complete mediation for the negative relationship of dCOR with figure recall. These results suggest that cortisol might have enhancing effects on visuospatial encoding as well as impairing effects on visuospatial retrieval, possibly due to its occupancy patterns of corticosteroid receptors. Cortisol's adverse effects on visuospatial retrieval might be explained through cortisol-related rostral hippocampal connectivity with the iLOC, which is a part of the extrastriate cortex implicated in visuospatial perception. Thorough dissection of hippocampal-prefrontal-extrastriate connectivity might facilitate the understanding of neural mechanisms underlying cortisol's contrasting effects on encoding (or consolidation) and retrieval of visuospatial information.