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Automatic algorithms are a proposed alternative to manual assessment of polysomnography data for analyzing sleep structure; however, none are acceptably accurate for clinical use. We investigated the feasibility of an automated sleep stage scoring system called Sleep Scope, which is intended for use with portable 1-channel electroencephalograph, and compared it with the traditional polysomnography scoring method. Twenty-six outpatients and fourteen healthy volunteers underwent Sleep Scope and polysomnography assessments simultaneously. Polysomnography records were manually scored by three sleep experts. Sleep Scope records were scored using a dedicated auto-staging algorithm. Sleep parameters, including total sleep time, sleep latency, wake after sleep onset, and sleep efficiency, were calculated. The epoch-by-epoch pairwise concordance based on the classification of sleep into five stages (i.e., wake, rapid eye movement, N1, N2, and N3) was also evaluated after validating homogeneity and bias between Sleep Scope and polysomnography. Compared with polysomnography, Sleep Scope seemed to overestimate sleep latency by approximately 3 min, but there was no consistent tendency in bias in other sleep parameters. The Κ values ranged from 0.66 to 0.75 for experts’ inter-rater polysomnography scores and from 0.62 to 0.67 for Sleep Scope versus polysomnography scores, which indicated sufficient agreement in the determination of sleep stages based on the Landis and Koch criteria. We observed sufficient concordance between Sleep Scope and polysomnography despite lower concordance in sleep disorder patients. Thus, this auto-staging system might serve as a novel clinical tool for reducing the time and expenses required of medical staff and patients.

Grief reactions to the bereavement of a close individual could involve empathy for pain, which is fundamental to social interaction. To explore whether grief symptoms interact with social relatedness to a person to whom one directs empathy to modulate the expression of empathy, we administered an empathy task to 28 bereaved adults during functional magnetic resonance imaging, in which participants were subliminally primed with facial stimuli (e.g., faces of their deceased or living relative, or a stranger), each immediately followed by a visual pain stimulus. Individuals’ grief severity promoted empathy for the pain stimulus primed with the deceased’s face, while it diminished the neural response to the pain stimulus primed with the face of either their living relative or a stranger in the medial frontal cortex (e.g., the right dorsal anterior cingulate cortex). Moreover, preliminary analyses showed that while the behavioral empathic response was promoted by the component of “longing” in the deceased priming condition, the neural empathic response was diminished by the component of “avoidance” in the stranger priming condition. Our results suggest an association between grief reactions to bereavement and empathy, in which grief symptoms interact with interpersonal factors to promote or diminish empathic responses to others’ pain.

Health effects of weekend catch-up sleep (CUS) could differ depending on both the ability to obtain sufficient sleep during weekdays and amount of weekend CUS required to compensate for sleep lost during the week. Using data from 3128 middle-aged (40–64 years) participants of the Sleep Heart Health Study, we examined the longitudinal association of these two aspects of sleep with all-cause mortality. CUS was calculated as the difference in self-reported habitual sleep duration between weekends and weekdays, and classified into no, short (1 h), and long (2 h or more) CUS. Polysomnography-measured total sleep time, representing the ability to obtain sufficient sleep, was classified into short (

Comorbid insomnia and poor sleep quality in Parkinson's disease (PD) are associated with a poor health-related quality of life (HRQoL). However, the relationship between HRQoL and sleep measures obtained using polysomnography (PSG) remains unclear. We aimed to examine the association between various sleep measures and HRQoL in PD patients.We retrospectively included patients with PD who underwent PSG and responded to self-administered questionnaires including the Pittsburgh Sleep Quality Index (PSQI) and Medical Outcomes Study 36-Item Short-Form Health Survey.The patients' (n = 120) mean age was 67.06 (SD = 8.77) years, and their mean Hoehn and Yahr stage was 2.25 (SD = 0.78). A higher PSQI score (worse subjective sleep quality) was correlated in PSG with shorter sleep latency, less N1 sleep, and more N2 sleep. Multiple regression analysis showed that the total PSQI score correlated with both physical and mental HRQoL (p 0.001 in both cases). However, neither type of HRQoL studied correlated with objective sleep measures, including indicators of sleep architecture, sleep-disordered breathing, and sleep related movement disorders.Despite the association between subjective sleep quality and HRQoL, the associations between objective measures and HRQoL were negligible. Objective sleep fragmentation may not be perceived as a sleep disturbance in patients with PD, and therefore may not adversely affect their subjective health, given the paradoxical correlation between PSQI score and sleep architecture.

Background:Nonrestorative sleep (NRS), defined as insufficiently rested or refreshed sleep, is considered to play an important role in the development of depression. The aim of this study is to investigate the predictive ability of insomnia-related symptoms, including NRS, for incident depressive symptoms (DEPs) in a longitudinal manner., Methods:We used data of 1196 samples aged 18–64 years who participated in both the Hispanic Community Health Study/Study of Latinos conducted in 2008–2010 and the follow-up study (Sueño Ancillary Study) conducted in 2010–2013. DEPs and insomnia-related symptoms (difficulty initiating sleep [DIS], difficulty maintaining sleep [DMS], early morning awakening [EMA], difficulty returning to sleep [DRS], and NRS) were evaluated by the 10-item Center for Epidemiologic Studies Depression Scale and the Women's Health Initiative Insomnia Rating Scale, respectively. A logistic regression analysis was used to evaluate the predictive ability of each insomnia-related symptom at baseline for incident DEPs in couple-years., Results:In the univariate logistic regression analysis, all insomnia-related symptoms had significant associations with incident DEPs (DIS, odds ratio [OR] = 1.6; DMS, OR = 1.6; EMA, OR = 1.5; DRS, OR = 1.9; NRS, OR = 2.5). After adjusting for sociodemographic factors and the confounding effects of other insomnia-related symptoms, only NRS (OR = 2.2, 95% confidence interval = 1.4–3.5, p = .001) was significantly associated with incident DEPs., Conclusions:NRS was a risk factor for incident DEPs, which includes a predictive ability for other insomnia-related symptoms. Our results suggest that focusing on NRS is an effective strategy for preventing depression in public health promotions.

Background: The average sleep duration of Japanese people is shorter than that of people from other countries, and bedtime procrastination is suspected to be one of the factors contributing to this issue. This study aimed to develop and validate the Japanese version of the Bedtime Procrastination Scale (BPS-J). Methods: The BPS-J was developed through procedures including the translation and back-translation of the scale, cognitive interviews with 100 participants who reported insufficient sleep syndrome (ISS) using open-ended online questionnaires, and expert checking. To investigate the scale’s validity and reliability, an online survey was conducted with daytime workers aged 20-65 years without sleep disorders other than ISS. Half of the participants were retested using the same survey after 14 days. Participants’ responses to the Brief Self-Control Scale (BSCS), General Procrastination Scale (GPS), and Munich ChronoType Questionnaire (MCTQ), and data on sleep-related variables such as sleep duration on workdays and the days per week of fatigue or sleep loss, sex, and age, were collected. Results: We analyzed data from 574 participants to assess scale validity. We then analyzed data from 280 participants to determine test-retest reliability. Confirmatory factor analyses revealed that the two-factor model without Item 2 was most suitable for the BPS-J, unlike other language versions. Regardless of the full-item model or the model with Item 2 eliminated, sufficient reliability and significant correlations with the BSCS, GPS, MCTQ, and sleep-related variables such as sleep duration per night on work days, days per week of feeling fatigued, and days per week of sleep losswere observed. Logistic and linear regressions showed that the relationships between the BPS-J, sleep-related variables, and MCTQ were maintained after adjusting for sex and age. Conclusion: The BPS-J was found to have sufficient validity and reliability. Further, eliminating Item 2 from the original version of the Bedtime Procrastination Scale was found to be better to adapt the scale for Japanese daytime workers.

Introduction Associations of sleep duration with health outcomes could differ depending on whether sleep is restorative. Age-related changes in the relationship between sleep need and sleep opportunity could also influence these associations. Methods Using data from 5804 participants of the Sleep Heart Health Study, a multicenter population-based prospective cohort study, we examined the longitudinal association of feeling rested after sleep combined with in-home polysomnographymeasured total sleep time (TST) or time in bed (TIB) with allcause mortality. Results A total of 223 (7.1%) and 991 (37.0%) deaths were reported in 3128 middle-aged (40–64 years) and 2676 older adults (≥ 65 years) with a mean (standard deviation) age of 54.5 (6.6) and 73.3 (5.7) years at baseline over a median (interquartile range) follow-up time of 12.3 (11.3–13.5) and 11.3 (8.2–12.2) years, respectively. Among middleaged adults, compared with the interquartile TST range (331 to < 414 min) with feeling rested, the lowest TST quartile (< 331 min) with feeling unrested was associated with higher mortality (adjusted hazard ratio [aHR], 1.54; 95% confidence interval [CI] 1.01–2.33); the highest TST quartile (≥ 414 min) with feeling rested was associated with lower mortality, independently from health and sleep covariates (aHR, 0.55; 95% CI 0.32–0.97). Among older adults, TIB, but not TST, was consistently associated with mortality. Compared with the interquartile TIB range (404 to < 482 min) with feeling rested, the highest TIB quartile (≥ 482 min) with feeling unrested was associated with higher mortality (aHR, 1.57; 95% CI 1.23–2.01). Conclusion The results suggest the role of restorative sleep in differentiating the effects of sleep duration on mortality outcomes for middle-aged and older adults. Our findings further suggest that there is a need to change the way to optimize sleep hygiene according to age groups: in middle-aged adults maintaining a substantial amount of sleep is more critical, whereas in older adults optimizing sleep opportunity is more critical to determine the sleep–mortality relationship. Support (if any) This work was supported by the Ministry of Health, Labor and Welfare, Government of Japan (Grant numbers #19FA1009 and #21FA1002).

Introduction Polysomnography (PSG) has been suggested to be useful as an objective indicator (biomarker) that contributes to the diagnosis and severity evaluation of various sleep disorders. However, its regular use is still limited to the specialized institutions for sleep disorders. Therefore, PSG is essential for clinical diagnosis of only some sleep disorders, and further application of PSG in conjunction with biomarker development of disorders including such as insomnia, and psychiatric disorders with comorbid sleep disorders is expected. The aim of this project is to establish a PSG databank for sleep disorders in collaboration with major PSG laboratories in Japan. Methods This project is collaborated with medical and research institutions that conduct PSG on a large scale in Japan. The National Center of Neurology and Psychiatry (NCNP) serves as the core institution. The initial collaborating institution is the Tokyo Medical University, which is in cooperation with the Yoyogi Sleep Disorder Center, the largest PSG facility in the Kanto region. We also collaborate with three other core PSG facilities in the Kanto, Tohoku and Kyushu regions: the Nihon University, the Akita University (in cooperation with the Akita Sleep Clinic), and the Kurume University. This project has been approved by the Ethics Committee of the NCNP. Results We have stored about 3,000 PSG data evaluated by the standard of the American Academy of Sleep Medicine clinical practice guideline or the traditional Rechtschaffen & Kales standard with adjunct clinical metadata for the past 9 years at the NCNP, about 17,900 at the Tokyo Medical University, about 1,900 at the Nihon University, about 500 at the Akita University, and about 3,000 at the Kurume University. We are continuously collecting and banking data for enhancing research availability of the PSG databank for sleep disorders. Conclusion The collected data will be used for research on the development of objective indices for sleep disorders or neuropsychiatric disorders, for which objective indices are lacking in diagnosis and pathological evaluation. Support (if any) This work was supported by the Intramural Research Grant (#2-1) for Neurological and Psychiatric Disorders of NCNP.

Although standing plantar perception training (SPPT) may improve standing postural stability, the underlying neural mechanisms remain unclear. The authors investigated the relationship between regional cortical responses to SPPT using a balance pad and training outcomes in 32 older participants (mean ± SD:72.2 ± 6.0, range:60–87). Regional cortical activity was measured in the bilateral supplementary motor area, primary sensorimotor area, and parietal association area using near-infrared spectroscopy. Postural sway changes were compared before and after SPPT. Changes in two-point plantar discrimination and regional cortical activity during SPPT, associated with standing postural stability improvements, were examined using multiple regression and indicated improved standing postural stability after SPPT (p

Introduction There is evidence for a mismatch between subjective and objective sleep durations not only in individuals with insomnia but also in healthy individuals . However, it is unclear how such discrepancy impacts long-term health outcomes. This study investigated whether and how the discrepancy between subjective and objective sleep duration affected all-cause mortality in a sample of community-dwelling older adult men, aged ≥ 65 years. Methods We conducted a secondary analysis of data obtained via the Osteoporotic Fractures in Men Sleep Study, a community-based, longitudinal, observational, and multicenter study. We included data from 2,674 individuals who underwent an in-home polysomnography, completed morning surveys to assess subjective sleep duration during the polysomnography, and for whom survival or death data were available. We assessed the longitudinal association between misperception index (MI), calculated as MI = (objective sleep duration – subjective sleep duration) / objective sleep duration, and all-cause mortality. MI was treated as both a continuous and categorical predictor: the lowest (≤ -0.19; the overestimation of sleep duration) and highest MI quartiles (> 0.08; the underestimation of sleep duration) were compared to the interquartile range of MI (-0.19 Results During the follow-up with a mean (standard deviation) of 10.8 (4.2) years, 1,596 deaths (59.7%) were observed. As a continuous variable, MI showed a negative association with all-cause mortality after adjusting for multiple covariates, including polysomnography-measured objective sleep duration (fully adjusted hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.56–0.84). As a categorical variable, the lowest MI quartile (vs. the interquartile MI range) was associated with increased mortality (fully adjusted HR, 1.28; 95% CI, 1.12–1.46), whereas the highest MI quartile was not associated with mortality (fully adjusted HR, 0.97; 95% CI, 0.85–1.11). Conclusion The subjective overestimation (“reverse” misperception) of sleep duration, may be a risk factor for all-cause mortality in older men. Further investigations are needed to examine physiological mechanisms through which subjective overestimation of sleep duration leads to negative long-term health outcomes. Support (if any) This work was supported by the Ministry of Health, Labor and Welfare, Government of Japan (Grant numbers #19FA1009 and #21FA1002).

A discrepancy in subjective and objective estimations of sleep duration, which often diverge, could have long-term adverse effects on health outcomes in older adults. Using data from 2674 older adult men (≥ 65 years of age) of the Osteoporotic Fractures in Men Sleep Study, we assessed the longitudinal association between misperception index (MI), calculated as MI = (objective sleep duration – subjective sleep duration)/objective sleep duration, and all-cause mortality. During the follow-up with a mean (standard deviation) of 10.8 (4.2) years, 1596 deaths were observed. As a continuous variable, MI showed a linear relationship with all-cause mortality after adjusting for multiple covariates, including polysomnography-measured objective sleep duration [fully adjusted hazard ratio (HR), 0.69; 95% confidence interval [CI], 0.56–0.84]. As a categorical variable, the lowest MI quartile (vs. the interquartile MI range) was associated with increased mortality (fully adjusted HR, 1.28; 95% CI, 1.12–1.46), whereas the highest MI quartile was not associated with mortality (fully adjusted HR, 0.97; 95% CI, 0.85–1.11). The subjective overestimation of sleep duration may be a risk factor for all-cause mortality in older men. Future studies should examine why subjective overestimation of sleep duration is associated with all-cause mortality from a physiological perspective.

Background It is unclear whether the toe grip force (TGF) of the dominant foot (DF) and the lower limb function asymmetry (LLFA) in older adults are associated with fall risk. Therefore, this study aimed to investigate the effect of lower limb properties (such as TGF, muscle strength, and plantar sensation) on the risk of falls in older adults, while considering the foot dominance and asymmetry of lower limb function. Methods This study was a cross-sectional study. We determined whether the lower limb function of the DF and non-dominant foot (non-DF) and LLFA had any effect on the fall risk in 54 older adults (mean ± standard deviation: 72.2 ± 6.0, range: 60–87 years). We examined the participants’ fall history, Mini-Mental State Examination (MMSE) score, lower limb function, and LLFA. To determine fall risk factors, we performed logistic regression analysis, with presence or absence of falls as the dependent variable. Results The independent variables were age, sex, MMSE score, two-point discrimination of the heel (non-DF) as plantar sensation index, and the TGF of both feet. Only the TGF of the DF was identified as a risk factor for falls (p Conclusions In older adults, clinicians should focus on the TGF of the DF as a risk factor for falls. Trial registration This study was retrospectively registered. https://center6.umin.ac.jp/cgi-bin/ctr/ctr_up_rec_f1.cgi.

A link has been suggested between somatic anxiety (SA) and insomnia in the cognitive model of chronic insomnia. This cross-sectional study examined if the possible link between insomnia symptoms and SA is related to an increased dosage of hypnotics/anxiolytics and poor clinical outcome in residual major depressive disorder (MDD). We studied 72 MDD outpatients, in partial or complete remission, enrolled in a rehabilitation program. Contributory subscales of the Hamilton Depression Rating Scale for residual symptoms were identified using principal component analysis. Unfavorable effects of SA × insomnia interaction on GABAergic pharmacotherapy and the probability of remission were assessed using moderation analysis. Patients with insomnia symptoms (43%) were less likely to achieve remission than those without. Residual symptoms formed the first component, and insomnia symptoms alone formed the second component (R2X = .33, Q2 = .09). The presence of insomnia symptoms was associated with an increase in SA (p = .048) but not with core depression or somatic symptoms. The SA × insomnia interaction was associated not only with increased hypnotic (b = –2.30, p = .014) and anxiolytic (b = 9.78, p = .002) dosages but also with a lower probability of remission (b = 1.18, p = .037). These results suggest a mutual detrimental interaction between SA and insomnia symptoms for maintaining residual MDD. Addressing the link between SA and insomnia symptoms may be important for effectively treating MDD.

BACKGROUND: Temporal processing, crucial to guide behavior toward a goal, may have a role in forming a depressive episode, yet it remains unclear which properties of temporal processing are central to antidepressant response. Production of a short duration oscillates in a circadian manner. Altered circadian organization of physiology and behavior are a hallmark of bipolar disorder. We thus tested whether circadian dynamics of time production associate with treatment response in bipolar disorder. METHODS: Over the three cycles of total sleep deprivation combined with light therapy (chronotherapeutics) in one week, 20 inpatients with a major depressive episode in the course of bipolar disorder produced 10s and rated their subjective mood and vigilance levels repeatedly. RESULTS: Eleven patients (58%) among 19 completers achieved remission. Produced time intervals (PTIs) fluctuated more synchronously with mood levels (r=-0.77) than vigilance levels (r=-0.59) during treatment. A higher degree of shortening of PTIs, but not changes in mood or vigilance levels, during the initial 24-h period of treatment predicted better response (LR χ2=4.58, P=0.032). Strong opposite daily changes for PTIs and mood levels observed at baseline were both attenuated after treatment only in remitters (F=7.25, P=0.015). LIMITATIONS: Potential external confounders that affect time perception were not controlled. CONCLUSIONS: The results are the first to demonstrate an association of the circadian properties of time perception with antidepressant effects of chronotherapeutics and suggest the potential utility of time production in predicting clinical outcome of bipolar depression.

Associations of sleep duration with human health could differ depending on whether sleep is restorative. Using data from 5804 participants of the Sleep Heart Health Study, we examined the longitudinal association of sleep restfulness combined with polysomnography-measured total sleep time (TST) or time in bed (TIB), representing different sleeping behaviors, with all-cause mortality. Among middle-aged adults, compared with restful intermediate TST quartile, the lowest TST quartile with feeling unrested was associated with higher mortality (hazard ratio [HR], 1.54; 95% confidence interval [CI] 1.01–2.33); the highest TST quartile with feeling rested was associated with lower mortality (HR, 0.55; 95% CI 0.32–0.97). Among older adults, the highest TIB quartile with feeling unrested was associated with higher mortality, compared with restful intermediate TIB quartile (HR, 1.57; 95% CI 1.23–2.01). Results suggest a role of restorative sleep in differentiating the effects of sleep duration on health outcomes in midlife and beyond.

Bright light (BL) therapy is clinically utilized for treatment of sleep–wake disorders through the manipulation of circadian oscillation. It is also extended to depressive disorders including seasonal affective disorder through emotional regulation. Recently, it has been suggested that BL facilitates memory encoding and consolidation via another psychophysiological mechanism of perceptual information processing in the brain. In particular, BL can help to alleviate stress associated with processing of fear memories. In this study, we explored a potential application of BL for treatment of stress-induced and fear circuitry disorders in patients receiving exposure-based cognitive behavioral therapy (CBT). Fourteen patients with panic disorder (PD) or posttraumatic stress disorder (PTSD) were enrolled in a single-blind, randomized control trial to assess BL exposure (8000-lux, 30 min, 9 times, 2 weeks apart) compared to sham light (SL) exposure (800-lux, the same duration and frequency), while patients were concurrently receiving exposure-based CBT. The State Trait Anxiety Index (STAI) and the self-rating version of Montgomery–Asberg Depression Rating Scale (MADRS-S) assessed anxiety-related severity scores before and after therapy. After dropouts, 10 participants remained. STAI and MADRS-S scores showed a significantly greater reduction in the BL group than in the SL group. BL may be an effective augmentative therapy when used with exposure-based CBT for PD and PTSD patients. Future trials with larger sample sizes that are adequately statistically powered are required to confirm these preliminary findings.

This study investigated the difference in the severity of mental distress and factors contributing to mental distress in frontline and non-frontline healthcare professionals during the coronavirus disease (COVID-19) pandemic. A cross-sectional web-based survey of medical staff collected by snow-ball sampling was performed in Japan in October 2020 using the Kessler Psychological Distress Scale (K6) as an outcome measure for mental distress. Originally developed items asking about the degree of change in psychological and physical burdens, COVID-19-related fear, and experience of discrimination were obtained. The median score of the K6 was 7 in the frontline staff group (n = 86) and 6 in the non-frontline staff group (n = 504), without a statistically significant difference. Multiple regression analyses showed that among the participants, an increase in psychological burden and COVID-19-related fear was significantly associated with mental distress in both groups. Experience of discrimination was significantly associated with mental distress only in the frontline staff group. However, an increase in physical burden was significantly associated with mental distress only in the non-frontline staff group. The results indicate that the factors contributing to mental distress between frontline and non-frontline staff can be different, although the severity of mental distress is comparable between them.

BACKGROUND There are numerous reports on the psychological burden of medical workers after the COVID-19 outbreak; however, no study has examined the influence of developmental characteristics on the mental health of medical workers. OBJECTIVE The objective of this study was to examine whether the developmental characteristics of medical workers are associated with anxiety and depression after the COVID-19 outbreak. METHODS An online questionnaire survey was conducted in October 2020. The questionnaire included items on sociodemographic data, changes in their life after the COVID-19 outbreak, and symptoms of depression, anxiety, attention deficit/hyperactivity disorder (ADHD) traits, and autism spectrum disorder traits. We performed hierarchical multiple regression analyses. RESULTS The data of 640 medical workers were analyzed. Increases in physical and psychological burden were observed in 49.1% and 78.3% of the subjects, respectively. The results of a multiple regression analysis showed that ADHD traits were significantly associated with both depression (β=0.390, P CONCLUSIONS Globally, the burden on medical workers increased. This study suggested that medical workers with higher ADHD traits may need special attention during the COVID-19 pandemic.

Cognitive behavioral therapy for insomnia (CBT-I) is a first-line therapy for insomnia disorders. We assessed changes in discrepancies between subjective and objective sleep measures and correlations between discrepancy changes and clinical insomnia severity for CBT-I in patients with primary insomnia METHODS: Fifty-two outpatients (mean age, 60.3 years; 26 women) with primary insomnia were treated by individual CBT-I (50 min, maximum six sessions, once every 1-2 weeks). One week before and after CBT-I, patients recorded a sleep log and wore an actigraphy device. Subjective and objective time in bed (TIB), total sleep time (TST), sleep-onset latency (SOL), wake time after sleep onset (WASO), and sleep efficiency (SE) were evaluated by averaging 1-week records. Relative values of sleep discrepancy in TIB, TST, SOL, WASO, and SE were calculated for estimating effects of CBT-I. The therapeutic effects were also evaluated using psychological scales before and after CBT-I.Subjective and objective discrepancies in sleep measures decreased by 36, 25, and 37 min in TST, SOL, and WASO, respectively, and 7% in SE (all P 0.001) after CBT-I. Seven patients transitioned from underestimating SE before CBT-I to overestimating SE after CBT-I. Although CBT-I improved relative values of discrepancy in WASO and SE, alongside ISI, the improvement in insomnia severity only correlated with SOL discrepancy.CBT-I may reduce the discrepancy between subjective and objective sleep measures in patients with primary insomnia. However, a greater therapeutic effect of CBT-I was observed in reducing the ISI, which was slightly influenced by improvements in sleep discrepancies.

Background To date, no previous studies have evaluated the relationship between sleep duration and quality of life (QOL) or depression in the general population after controlling for daytime sleepiness and sleep disturbances. Methods A web-based cross-sectional survey was conducted with 8698 subjects aged 20–69 years. We examined the relationships between weekday sleep duration and daytime sleepiness, sleep disturbance, QOL and depression, using the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (without the item for sleep duration), 8-item Short Form and Center for Epidemiological Studies Depression Scale (CES-D). Results Daytime sleepiness tended to increase in proportion to shorter weekday sleep durations. Sleep disturbances, physical and mental QOL, and CES-D scores were worse in both the shorter and longer sleep groups compared with the group with 7–8 h of sleep. Hierarchical logistic regression analyses revealed that short sleep duration but not long sleep duration was significantly associated with reduction of both physical and mental QOL, even after controlling for the presence of daytime sleepiness and sleep disturbance. Both short and long sleep duration were independently and significantly correlated with depression after controlling for daytime sleepiness; however, there was no statistically significant association after adjusting for the effects of sleep disturbance. Conclusions The results suggested adverse effects of short sleep but not long sleep on both physical and mental QOL. In addition, the negative impact of specific types of sleep disturbance on depression may be greater than the impact of shortening of sleep duration.

Bright light (BL) not only regulates human emotion and circadian physiology but can also directly modulate emotional memories. Impaired fear extinction and enhanced fear acquisition and consolidation are hallmarks of fear-circuitry disorders; thus, we tested whether BL facilitates fear extinction and inhibits fear acquisition. We randomly exposed 29 healthy humans to high- (9000 lx) or low-intensity light (500 lx) for 15 min, near the nadir of the phase response to light, in a single-blind manner. Simultaneously with the light exposure, subjects performed fear extinction training and second fear acquisition, where a visual conditioned stimulus (CS), previously paired with an electric shock unconditioned stimulus (US), was presented without the US, while another CS was newly paired with the US. Conditioned responses (CRs) and changes in prefrontal cortex (PFC) activity were determined during encoding and delayed recall sessions. BL-exposed subjects exhibited lower extinction-related PFC activity and marginally higher acquisition-related PFC activity during light exposure than subjects exposed to control light. Twenty-four hours later, BL reduced CRs to both the extinguished and non-extinguished CSs with marginally lower extinction-related PFC activation, suggesting that BL enhanced fear extinction, while suppressing fear acquisition. Further, BL sustained tolerance to fear re-conditioning. Our results demonstrate that a single and brief BL exposure, synchronized with fear extinction and acquisition, instantaneously influences prefrontal hemodynamic responses and alleviates fear expression after 24 h. Although the specificity of BL effects deems further investigation, our findings indicate the clinical relevance of adjunctive BL intervention in exposure-based cognitive-behavioral therapy for fear-circuitry disorders.

Light has attracted increasing attention as a critical determinant of memory processing. While sleep selectively consolidates newly encoded memories according to their future relevance, the role of light in human memory consolidation is largely unknown. Here, we report how bright light (BL), provided during encoding, influences online and offline consolidation of motor skill learning. We sought to determine whether relatively slower and faster key-press transitions within individuals were differentially consolidated by BL. Healthy human subjects were briefly exposed to either BL (8000 lx) or control light (CL;500 lx) during memory encoding at 13:00 h, when light minimally affects circadian phase-shifting, and were retested 24 h later. The effects of BL on online and offline performance gains were determined by accuracy and speed. BL-exposed subjects showed better overall performance accuracy during training and lower overnight accuracy gains after a subsequent night of sleep than did CL-exposed subjects. BL preferentially improved the initially most difficult individual key-press transitions during practice; these were only improved overnight under CL. By contrast, accuracy during what had been the easiest key-press transitions at the beginning of the experiment was unaffected by light conditions or online/offline learning processes. BL effects were not observed for performance speed, mood, or sleep-wake patterns. Brief BL exposure during training may advance motor memory selection and consolidation that optimally meet individual requirements for potential gains, which would otherwise depend on post-training sleep. This suggests a new way of enhancing brain plasticity to compensate for impaired sleep-dependent memory consolidation in neuropsychiatric conditions.

Delayed encephalopathy (DE) affects not only the cerebral white matter and globus pallidus but also the cortex and thalamus. However, it remains unknown whether these brain lesions alter sleep along with clinical manifestations of DE. A 46-year-old man with DE underwent repetitive hyperbaric oxygen therapy. The patient was evaluated by not only neuropsychological and neuroimaging testing but polysomnography over the clinical course. Neurological symptoms improved markedly; however, profound frontal cognitive deficits continued. The polysomnography revealed prolonged absence and delayed recovery of sleep spindles across recordings. Alterations in spindle oscillations in DE could provide further insight into sleep regulatory networks.

Higher wake promotion against sleep drive boosts cognitive processing, but it also seems to increase the risk of insomnia by reinforcing an obsession with sleep in neurotic patients. To explore whether a personality trait of neuroticism simultaneously facilitates wake-promoting ability and sleep devaluation via a common regional prefrontal function under a sleep-restricted condition, working memory tasks were administered to 49 healthy humans after a 2-h sleep restriction. Higher wake-promoting ability demonstrated in a high-load task was correlated with lower bilateral prefrontal activation, as measured by near-infrared spectroscopy. Structural equation modeling revealed that neuroticism predicts sleep devaluation and wake-promoting ability via left and right regional prefrontal efficiency, respectively. Our results indicate that neuroticism-related neural efficiency increases resilience to sleepiness, but decreases sleep satisfaction.

The effectiveness of D-cycloserine (DCS), an N-methyl-D-aspartate glutamate receptor partial agonist, and valproic acid (VPA), a histone deacetylase inhibitor, in facilitating the extinction of fear-conditioned memory has been explored in humans and animals. Here, we confirmed whether DCS (100 mg) and VPA (400 mg) act in off-line learning processes during sleep or waking, for further clinical application to anxiety disorders and posttraumatic stress disorder (PTSD). We performed a randomized, blind, placebo-controlled clinical trial in 90 healthy adults. Visual cues and electric shocks were used as the conditioned stimulus (CS) and unconditioned stimulus (US), respectively. The extinction effect was observed not in simple recall after the extinction of coupled CS-US, but was observed in the post-re-exposure phase after unexpected re-exposure to reinstatement CS-US coupling. Newly acquired conditioned fear was also eliminated or habituated by DCS and VPA administration, in line with previous findings. Furthermore, VPA facilitated the off-line learning process of conditioned fear extinction and habituation during sleep, while DCS facilitated this process during waking. These novel findings suggest that DCS and VPA might enhance exposure-based cognitive therapy for anxiety disorders and PTSD by reducing the vulnerability to reinstatement and preventing relapses of fear-conditioned responses, and provide evidence for a peculiarity of the sleep-dependent off-line learning process for conditioned fear extinction. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

The sense of body ownership constantly adapts to new environments, and awareness of a distinction between oneself and others is a fundamental ability. However, it remains unclear whether plasticity in the sense of body ownership is dependent on genetic factors. The present study investigated the influence of the catechol-O-methyltransferase (COMT) Val158Met genotype on illusory learning of a sense of body ownership and dissociation. 76 healthy Japanese participants experienced the rubber hand illusion (RHI), which is produced by sensory integration of conflicting modalities, with the intent to experimentally alter objective perceived locations and subjective ownership ratings. We found that Val/Val homozygous participants had more intense RHI experiences than Val/Met heterozygous and Met homozygous participants. Furthermore, RHI sensation was correlated with a dissociative personality trait in Val/Val homozygous participants. Our findings indicate an interaction between COMT genotype, RHI sensation, and dissociative personality traits: Val/Val genotypes were associated with RHI induction and greater vulnerability to dissociation. The findings suggest that Val/Val homozygous individuals may be more flexible regarding self-attribution/body ownership and that biological factors may contribute to reduced awareness regarding the distinction between self and others.

Progressive supranuclear palsy (PSP) is a neurodegenerative disorder with diverse clinical phenotypes characterized by supranuclear gaze palsy, parkinsonism with postural instability, and frontal dementia. The early and accurate diagnosis of PSP remains difficult because of the variable combination of symptoms and frequent lack of gaze abnormalities early in the disease course. Moreover, a subset of PSP shows behavioral changes as the initial presentation, which considerably overlaps with the clinical picture of frontotemporal dementia (FTD). Thus, this subgroup possibly needs psychiatric assessments. Here, we describe a clinical case of PSP difficult to differentiate from FTD because the frontal presentation persisted without gaze palsy until the late stage of the clinical course. A 58-year-old man was admitted to our hospital for the reconsideration of a diagnosis of FTD. Disinhibited and gambling behaviors inconsistent with his previous personality first appeared at around the age of 45, with gradual progression, followed by memory deficits, executive dysfunction, and a slowing of mental processes. Recurrent sexual disinhibition led him to undergo psychiatric consultation at the age of 57. Downward gaze palsy and postural instability with recurrent falls emerged 8 months after the first psychiatric examination, and he was clinically diagnosed with PSP 13 years after the initial frontal presentation. PSP should be considered in the differential diagnosis of patients presenting with frontal lobe symptoms, even in psychiatric practice.

Sleep deprivation immediately following an aversive event reduces fear by preventing memory consolidation during homeostatic sleep. This suggests that acute insomnia might act prophylactically against the development of posttraumatic stress disorder (PTSD) even though it is also a possible risk factor for PTSD. We examined total sleep deprivation and memory suppression to evaluate the effects of these interventions on subsequent aversive memory formation and fear conditioning. Active suppression of aversive memory impaired retention of event memory. However, although the remembered fear was more reduced in sleep-deprived than sleep-control subjects, suppressed fear increased and seemed to abandon the sleep-dependent plasticity of fear. Active memory suppression, which provides a psychological model for Freud's ego defense mechanism, enhances fear and casts doubt on the potential of acute insomnia as a prophylactic measure against PTSD. Our findings bring into question the role of sleep in aversive-memory consolidation in clinical PTSD pathophysiology.

Higher wake promotion against sleep drive boosts cognitive processing, but it also seems to increase the risk of insomnia by reinforcing an obsession with sleep in neurotic patients. To explore whether a personality trait of neuroticism simultaneously facilitates wake-promoting ability and sleep devaluation via a common regional prefrontal function under a sleep-restricted condition, working memory tasks were administered to 49 healthy humans after a 2-h sleep restriction. Higher wake-promoting ability demonstrated in a high-load task was correlated with lower bilateral prefrontal activation, as measured by near-infrared spectroscopy. Structural equation modeling revealed that neuroticism predicts sleep devaluation and wake-promoting ability via left and right regional prefrontal efficiency, respectively. Our results indicate that neuroticism-related neural efficiency increases resilience to sleepiness, but decreases sleep satisfaction.

Copyright: © 2013 Kuriyama K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Approximately 10-30% of individuals experience insomnia worldwide [1,2]. Chronic insomnia causes disturbances to nighttime sleep, including prolonged sleep latency, disturbance of sleep maintenance, and non-restorative sleep. It can also cause various Impairments of Daytime Functioning (IDFs) such as fatigue, mood disturbance, irritability, reduced motivation and interest, attention deficit, and memory impairment, with a consequent decline in occupational, social, or leisure quality [3]. A socioeconomic study has predicted that IDFs have a greater impact on the global economy rather than disturbances in night time sleep resulting from insomnia [4]. As a result, IDFs associated with insomnia have recently been a subject of particular interest. However, since the biological background and pathogeny of IDFs has not yet been clarified, they are not unconsidered in the differential diagnosis of insomnia subtypes in the latest version of the International Classification of Sleep Disorders (ICSD-2) [5], published in 2005. However, the criteria of “primary insomnia” in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) will be changed to “insomnia disorder” in the fifth edition (DSM-V) [6], which will be released in 2013 [7]. In line with this modification, IDFs will be clearly defined as specified sequelae based on specific biological vulnerabilities to illness, contrasting with the traditional, ambiguous definitions of IDFs.

Working memory (WM) capacity improvement is impacted by sleep, and possibly by N-methyl-D-aspartate (NMDA) agonists such as D-cycloserine (DCS), which also affects procedural skill performance. However, the mechanisms behind these relationships are not well understood. In order to investigate the neural basis underlying relationships between WM skill learning and sleep, DCS, and both sleep and DCS together, we evaluated training-retest performances in the n-back task among healthy subjects who were given either a placebo or DCS before the task training, and then followed task training sessions either with wakefulness or sleep. DCS facilitated WM capacity enhancement only occurring after a period of wakefulness, rather than sleep, indicating that WM capacity enhancement is affected by a cellular heterogeneity in synaptic plasticity between time spent awake and time spent asleep. These findings may contribute to development, anti-aging processes, and rehabilitation of higher cognition.

We report the case of a 63-year-old woman with thiamine deficiency who showed auditory hallucinations, a delusion of persecution, catatonic stupor, and catalepsy but no neurological symptoms including oculomotor or gait disturbance. Brain MRI did not show high-intensity T2 signals in regions including the thalami, mamillary bodies, or periaqueductal area. Her thiamine concentration was 19 ng/mL, only slightly less than the reference range of 20-50 ng/mL. Her psychosis was unresponsive to antipsychotics or electroconvulsive therapy, but was ameliorated by repetitive intravenous thiamine administrations at 100-200 mg per day. However, one month after completing intravenous treatment, her psychosis recurred, even though she was given 150 mg of thiamine per day orally and her blood concentration of thiamine was maintained at far higher than the reference range. Again, intravenous thiamine administration was necessary to ameliorate her symptoms. The present patient indicates that the possibility of thiamine deficiency should be considered in cases of psychosis without neurological disturbance and high-intensity T2 MRI lesions. Also, this case suggests that a high blood thiamine concentration does not necessarily correspond to sufficient thiamine levels in the brain. Based on this, we must reconsider the importance of a high dose of thiamine administration as a therapy for thiamine deficiency. The validity of the reference range of the thiamine concentration, 20-50 ng/mL, is critically reviewed.

s / Brain Stimulation 8 (2015) 360e377 371 Discussion: This novel observation suggests that PFC stimulation via anodal tDCS may help in correcting deficits in antisaccade task performance. These preliminary findings suggest that enhancement of inhibitory function might be one of the mechanisms underlying the ameliorating effect of add-on tDCS on persistent auditory hallucinations in schizophrenia.