Pre-existing sleep problems as a predictor of post-acute sequelae of COVID-19.

Several months after COVID-19 many individuals still report persisting symptoms, the so-called 'post-COVID-19 syndrome'. An immunological dysfunction is one of the main pathophysiological hypotheses. As sleep is central to the functioning of the immune system, we investigated whether self-reported pre-existing sleep disturbance might be an independent risk factor for the development of post-COVID-19 syndrome. A total of 11,710 participants of a cross-sectional survey (all tested positive for severe acute respiratory syndrome coronavirus-2) were classified into probable post-COVID-19 syndrome, an intermediate group, and unaffected participants at an average of 8.5 months after infection. The case definition was based on newly occurring symptoms of at least moderate severity and ≥20% reduction in health status and/or working capacity. Unadjusted and adjusted odds ratios were calculated to investigate the association between pre-existing sleep disturbances and subsequent development of post-COVID-19 syndrome while controlling for a variety of demographic, lifestyle, and health factors. Pre-existing sleep disturbances were found to be an independent predictor of subsequent probable post-COVID-19 syndrome (adjusted odds ratio 2.7, 95% confidence interval 2.27-3.24). Sleep disturbances as part of the post-COVID-19 syndrome were reported by more than half of the participants and appeared to be a new symptom and to occur independent of a mood disorder in most cases. Recognition of disturbed sleep as an important risk factor for post-COVID-19 syndrome should promote improved clinical management of sleep disorders in the context of COVID-19. Further, it may stimulate further research on the effect of improving sleep on the prognosis of COVID-19 long-term sequelae and other post-viral conditions.

Nightmare frequency and nightmare distress in psychiatric inpatients.

Previous research indicated that the prevalence of frequent nightmares and/or the presence of a nightmare disorder is quite high in patients with mental disorders. In the present study, 75 randomly selected psychiatric inpatients were interviewed and completed questionnaires regarding nightmares, sleep, and psychopathology. The percentage of patients with nightmares once per week or more often was 61.54% in the group with PTSD diagnosis (N = 13) and 40.32% in the patients without PTSD diagnosis (N = 62). Moreover, depression scores and having PTSD were related to heightened nightmare distress. Based on the high prevalence rates of frequent nightmares, future research should aim at understanding better the interplay between psychopathology and nightmares and test whether nightmare interventions like Imagery Rehearsal Therapy might be beneficial for patients with mental disorders.

Association of polygenic risk for schizophrenia with fast sleep spindle density depends on pro-cognitive variants.

Cognitive impairment is a common feature in schizophrenia and the strongest prognostic factor for long-term outcome. Identifying a trait associated with the genetic background for cognitive outcome in schizophrenia may aid in a deeper understanding of clinical disease subtypes. Fast sleep spindles may represent such a biomarker as they are strongly genetically determined, associated with cognitive functioning and impaired in schizophrenia and unaffected relatives. We measured fast sleep spindle density in 150 healthy adults and investigated its association with a genome-wide polygenic score for schizophrenia (SCZ-PGS). The association between SCZ-PGS and fast spindle density was further characterized by stratifying it to the genetic background of intelligence. SCZ-PGS was positively associated with fast spindle density. This association mainly depended on pro-cognitive genetic variants. Our results strengthen the evidence for a genetic background of spindle abnormalities in schizophrenia. Spindle density might represent an easily accessible marker for a favourable cognitive outcome which should be further investigated in clinical samples.

[Cognitive disorders and sleep disturbances in long COVID]. / Kognitive Störungen und Schlafstörungen bei Long-COVID.

BACKGROUND: During the last 2 years of the coronavirus disease 2019 (COVID-19) pandemic, knowledge about the long-term effects of the disease, the so-called long COVID, has rapidly grown; however, many questions remain unanswered, especially regarding the causes of persistent symptoms and their prognosis. Cognitive disorders and sleep disturbances are among the most frequent complaints. Both are associated with severe suffering and significant impairment in everyday functioning. OBJECTIVE: What is known about the occurrence of cognitive disorders and sleep disturbances in long COVID? What are the influencing factors and what is known about the course over time and possible underlying mechanisms? What treatment options are available? MATERIAL AND METHOD: In a narrative review, the most important findings on cognitive disorders and sleep disturbances in long COVID are presented. An overview of cohort studies with data on the prevalence and influencing factors of both symptom complexes is given. Current knowledge and hypotheses on pathophysiological mechanisms are presented and an outlook on treatment approaches is given. RESULTS: About one in five of those affected report cognitive impairment more than 3 months after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and about one third report sleep disturbances. The latter comprise symptoms of insomnia as well as hypersomnia. Cognitive impairment and sleep disturbances occur in patients with all levels of initial disease severity. There are indications of an improvement of cognitive deficits over time but further longitudinal studies are needed. CONCLUSION: In addition to the prognosis, the underlying disease mechanisms are still insufficiently understood. Furthermore, there is a great need for research on the efficacy and specific effective factors of therapeutic interventions.

[Recommendations on performing polygraphy or polysomnography in the fields of psychiatry and psychotherapy : Position paper of the working group on sleep medicine of the German Association for Psychiatry, Psychotherapy and Psychosomatics]. / Empfehlungen zur Durchführung einer Polygraphie oder Polysomnographie im Bereich Psychiatrie und Psychotherapie : Positionspapier des DGPPN-Referats Schlafmedizin.

Difficulties in falling asleep and maintaining sleep, nonrestorative sleep and decreased daytime wakefulness represent very common but relatively unspecific health complaints. Around 100 specific sleep-related disorders will be classified in their own major chap. 7 (sleep wake disorders) for the first time in the upcoming 11th version of the International Classification of Diseases (ICD 11). With respect to the disciplines of psychiatry and psychotherapy there is a bidirectional relationship between mental health and sleep wake disorders. Sleep wake disorders can be an independent risk factor for the onset of a mental disorder and have a negative influence on the course of the disease. In addition, sleep wake disorders can also precede a mental disease as an early symptom and therefore be an important indication for early recognition. Many sleep wake disorders can be diagnosed based on the anamnesis and routine clinical investigations. In special cases, examination in a specialized sleep laboratory and treatment in a sleep medicine center following a staged care approach can be mandatory. Polysomnography represents the gold standard for the differential diagnostics; however, there is no legal foundation in the field of neuropsychiatric disorders for remuneration in the German healthcare system. This review summarizes the current guidelines with respect to the criteria for an investigation in a sleep laboratory from the perspective of the disciplines of psychiatry and psychotherapy. From this the requirements for guideline-conform diagnostics and treatment are derived.

Serum brain-derived neurotrophic factor (BDNF) in sleep-disordered patients: relation to sleep stage N3 and rapid eye movement (REM) sleep across diagnostic entities.

Experimental and clinical evidence suggests an association between neuroplasticity, brain-derived neurotrophic factor and sleep. We aimed at testing the hypotheses that brain-derived neurotrophic factor is associated with specific aspects of sleep architecture or sleep stages in patients with sleep disorders. We included 35 patients with primary insomnia, 31 patients with restless legs syndrome, 17 patients with idiopathic hypersomnia, 10 patients with narcolepsy and 37 healthy controls. Morning serum brain-derived neurotrophic factor concentrations were measured in patients and controls. In patients, blood sampling was followed by polysomnographic sleep investigation. Low brain-derived neurotrophic factor levels were associated with a low percentage of sleep stage N3 and rapid eye movement sleep across diagnostic entities. However, there was no difference in brain-derived neurotrophic factor levels between diagnostic groups. Our data indicate that serum levels of brain-derived neurotrophic factor, independent of a specific sleep disorder, are related to the proportion of sleep stage N3 and REM sleep. This preliminary observation is in accordance with the assumption that sleep stage N3 is involved in the regulation of neuroplasticity.

Fast sleep spindle reduction in schizophrenia and healthy first-degree relatives: association with impaired cognitive function and potential intermediate phenotype.

Several studies in patients with schizophrenia reported a marked reduction in sleep spindle activity. To investigate whether the reduction may be linked to genetic risk of the illness, we analysed sleep spindle activity in healthy volunteers, patients with schizophrenia and first-degree relatives, who share an enriched set of schizophrenia susceptibility genes. We further investigated the correlation of spindle activity with cognitive function in first-degree relatives and whether spindle abnormalities affect both fast (12-15 Hz) and slow (9-12 Hz) sleep spindles. We investigated fast and slow sleep spindle activity during non-rapid eye movement sleep in a total of 47 subjects comprising 17 patients with schizophrenia, 13 healthy first-degree relatives and 17 healthy volunteers. Groups were balanced for age, gender, years of education and estimated verbal IQ. A subsample of relatives received additional testing for memory performance. Compared to healthy volunteers, fast spindle density was reduced in patients with schizophrenia and healthy first-degree relatives following a pattern consistent with an assumed genetic load for schizophrenia. The deficit in spindle density was specific to fast spindles and was associated with decreased memory performance. Our findings indicate familial occurrence of this phenotype and thus support the hypothesis that deficient spindle activity relates to genetic liability for schizophrenia. Furthermore, spindle reductions predict impaired cognitive function and are specific to fast spindles. This physiological marker should be further investigated as an intermediate phenotype of schizophrenia. It could also constitute a target for drug development, especially with regard to cognitive dysfunction.

Reduced activation in the ventral striatum during probabilistic decision-making in patients in an at-risk mental state.

BACKGROUND: Patients with schizophrenia display metacognitive impairments, such as hasty decision-making during probabilistic reasoning - the "jumping to conclusion" bias (JTC). Our recent fMRI study revealed reduced activations in the right ventral striatum (VS) and the ventral tegmental area (VTA) to be associated with decision-making in patients with schizophrenia. It is unclear whether these functional alterations occur in the at-risk mental state (ARMS). METHODS: We administered the classical beads task and fMRI among ARMS patients and healthy controls matched for age, sex, education and premorbid verbal intelligence. None of the ARMS patients was treated with antipsychotics. Both tasks request probabilistic decisions after a variable amount of stimuli. We evaluated activation during decision-making under certainty versus uncertainty and the process of final decision-making. RESULTS: We included 24 AMRS patients and 24 controls in our study. Compared with controls, ARMS patients tended to draw fewer beads and showed significantly more JTC bias in the classical beads task, mirroring findings in patients with schizophrenia. During fMRI, ARMS patients did not demonstrate JTC bias on the behavioural level, but showed a significant hypoactivation in the right VS during the decision stage. LIMITATIONS: Owing to the cross-sectional design of the study, results are constrained to a better insight into the neurobiology of risk constellations, but not prepsychotic stages. Nine of the ARMS patients were treated with antidepressants and/or lorazepam. CONCLUSION: As in patients with schizophrenia, a striatal hypoactivation was found in ARMS patients. Confounding effects of antipsychotic medication can be excluded. Our findings indicate that error prediction signalling and reward anticipation may be linked to striatal dysfunction during prodromal stages and should be examined for their utility in predicting transition risk.

Pineal gland volume in primary insomnia and healthy controls: a magnetic resonance imaging study.

Little is known about the relation between pineal volume and insomnia. Melatonin promotes sleep processes and, administered as a drug, it is suitable to improve primary and secondary sleep disorders in humans. Recent magnetic resonance imaging studies suggest that human plasma and saliva melatonin levels are partially determined by the pineal gland volume. This study compares the pineal volume in a group of patients with primary insomnia to a group of healthy people without sleep disturbance. Pineal gland volume (PGV) was measured on the basis of high-resolution 3 Tesla MRI (T1-magnetization prepared rapid gradient echo) in 23 patients and 27 controls, matched for age, gender and educational status. Volume measurements were performed conventionally by manual delineation of the pineal borders in multi-planar reconstructed images. Pineal gland volume was significantly smaller (P < 0.001) in patients (48.9 ± 26.6 mm(3) ) than in controls (79 ± 30.2 mm(3) ). In patients PGV correlated negatively with age (r = -0.532; P = 0.026). Adjusting for the effect of age, PGV and rapid eye movement (REM) latency showed a significant positive correlation (rS  = 0.711, P < 0.001) in patients. Pineal volume appears to be reduced in patients with primary insomnia compared to healthy controls. Further studies are needed to clarify whether low pineal volume is the basis or the consequence of functional sleep changes to elucidate the molecular pathology for the pineal volume loss in primary insomnia.

Leptin plasma concentrations increase during antidepressant treatment with amitriptyline and mirtazapine, but not paroxetine and venlafaxine: leptin resistance mediated by antihistaminergic activity?

Treatment with several psychopharmacological agents has been associated with increased leptin plasma concentrations. We measured leptin plasma concentrations in 76 adult depressed patients after a 6-day washout phase and again after 35 days of treatment with amitriptyline or paroxetine, as well as in 73 depressed patients after 28 days of treatment with either mirtazapine or venlafaxine. Leptin plasma concentrations increased during treatment with amitriptyline and mirtazapine, even after controlling for increased body mass index and irrespective of response to treatment [14.5 (13.8) vs 20.3 (18.7) ng/mL, and 12.2 (15.8) vs 14.4 (16.5) ng/mL in the 2 cohorts, respectively]. In contrast, paroxetine and venlafaxine treatment was not associated with changes in leptin plasma concentrations [14.8 (12.0) vs 13.6 (10.6); 15.9 (17.3) vs 13.5 (14.6) ng/mL] nor with weight gain. We conclude that treatment with amitriptyline or mirtazapine is associated with an increase in leptin secretion beyond change in weight. Thus, high leptin levels apparently are ineffective in the control of weight gain, indicating leptin resistance. Leptin resistance may be mediated by an antihistaminergic effect on hypothalamic nuclei integrating signals relevant for energy balance.

Dreaming and Sleep-Related Metacognitions in Patients with Sleep Disorders.

Sleep-related metacognitions play a role in the etiology of insomnia and are distressing while falling asleep. Although similar concepts, such as thought suppression, have been studied in the context of dreaming, the relationship between sleep-related metacognitions and more negatively toned dreaming due to stressful pre-sleep experiences has yet to be studied. Overall, 919 patients with various sleep disorders completed the Metacognitions Questionnaire-Insomnia (MCQ-I20), Arousal Disposition Scale (APS), and Pre-Sleep Arousal Scale (PSAS) and kept a sleep diary over seven days eliciting dream recall, nightmare frequency, and the emotional tone of their dreams. The regression analysis showed that the MCQ-I20 (small effect size) and the APS (medium effect size) were associated with nightmare frequency and negatively toned dream emotions. These findings suggest that dysfunctional sleep-related metacognitions that are active prior to sleep are also associated with more negatively toned dreaming and more nightmares-even after controlling for trait arousability. It would be very interesting to study where therapeutic strategies, such as metacognitive therapy explicitly targeting sleep-related metacognition, could also be beneficial with regard to dreams (more positive dreams and fewer nightmares).

Restless Legs Syndrome Prevalence and Clinical Correlates Among Psychiatric Inpatients: A Multicenter Study.

Background: There are only limited reports on the prevalence of restless legs syndrome (RLS) in patients with psychiatric disorders. The present study aimed to evaluate the prevalence and clinical correlates in psychiatric inpatients in Germany and Switzerland. Methods: This is a multicenter cross-sectional study of psychiatric inpatients with an age above 18 years that were diagnosed and evaluated face-to-face using the International RLS Study Group criteria (IRLSSG) and the International RLS severity scale (IRLS). In addition to sociodemographic and biometric data, sleep quality and mood were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), and the Patient Health Questionnaire (PHQ-9). In addition to univariate statistics used to describe and statistically analyze differences in variables of interest between patients with and without RLS, a logistic model was employed to identify predictors for the occurrence of RLS. Results: The prevalence of RLS in a sample of 317 psychiatric inpatients was 16.4%, and 76.9% of these were diagnosed with RLS for the first time. RLS severity was moderate to severe (IRLS ± SD: 20.3 ± 8.4). The prevalences in women (p = 0.0036) and in first-degree relatives with RLS (p = 0.0108) as well as the body mass index (BMI, p = 0.0161) were significantly higher among patients with RLS, while alcohol consumption was significantly lower in the RLS group. With the exception of atypical antipsychotics, treatment with psychotropic drugs was not associated with RLS symptoms. Regarding subjective sleep quality and mood, scores of the PSQI (p = 0.0007), ISI (p = 0.0003), and ESS (p = 0.0005) were higher in patients with RLS, while PHQ-9 scores were not different. A logistic regression analysis identified gender (OR 2.67; 95% CI [1.25; 5.72]), first-degree relatives with RLS (OR 3.29; 95% CI [1.11; 9.73], ESS score (OR 1.09; 95% CI [1.01; 1.17]), and rare alcohol consumption (OR 0.45; 95% CI [0.22; 0.94] as predictors for RLS. Conclusions: Clinically significant RLS had a high prevalence in psychiatric patients. RLS was associated with higher BMI, impaired sleep quality, and lower alcohol consumption. A systematic assessment of restless legs symptoms might contribute to improve the treatment of psychiatric patients.

Comparison of established and novel purity tests for the quality control of heparin by means of a set of 177 heparin samples.

The widespread occurrence of heparin contaminated with oversulfated chrondroitin sulfate (OSCS) in 2008 initiated a comprehensive revision process of the Pharmacopoeial heparin monographs and stimulated research in analytical techniques for the quality control of heparin. Here, a set of 177 heparin samples from the market in 2008 as well as pure heparin sodium spiked with defined amounts of OSCS and DS were used to evaluate established and novel methods for the quality control of heparin. Besides (1)H nuclear magnetic resonance spectroscopy (NMR), the assessment included two further spectroscopic methods, i.e., attenuated total reflection-infrared spectroscopy (ATR-IR) and Raman spectroscopy, three coagulation assays, i.e., activated partial thromboplastin time (aPTT) performed with both sheep and human plasma and the prothrombin time (PT), and finally two novel purity assays, each consisting of an incubation step with heparinase I followed by either a fluorescence measurement (Inc-PolyH-assay) or by a chromogenic aXa-assay (Inc-aXa-assay). NMR was shown to allow not only sensitive detection, but also quantification of OSCS by using the peak-height method and a response factor determined by calibration. Chemometric evaluation of the NMR, ATR-IR, and Raman spectra by statistical classification techniques turned out to be best with NMR spectra concerning the detection of OSCS. The validity of the aPTT, the current EP assay, could be considerably improved by replacing the sheep plasma by human plasma. In this way, most of the contaminated heparin samples did not meet the novel potency limit of 180 IU/mg. However, also more than 50% of the uncontaminated samples had <180 IU/MG. In contrast to the aPTT, the PT specifically detects OSCS and other heparin mimetics (LOD 3%). About ten times more sensitive are both the Inc-PolyH-assay and the Inc-aXa-assay, two rapid and simple quantification assays for heparin mimetics. The determined OSCS contents of the heparin samples excellently correlated with those calculated from the NMR spectra. In conclusion, NMR proved to be the current spectroscopic method of choice. The two two-step-assays represent options to supplement NMR, especially as tests for the initial screening, since they detect any heparin mimetic without requiring special expertise for interpretation of the results.

The effect of a 4-week treatment with reboxetine on metabolic parameters of depressed inpatients.

In the present study, we examined several metabolic parameters in a group of 19 acutely depressed inpatients with major depression (DSM-IV) at baseline and investigated their development after 4 weeks of antidepressant treatment with reboxetine (8-12 mg per day). We performed oral glucose tolerance tests and additionally assessed free saliva cortisol and post-dexamethasone cortisol levels, as well as whole cholesterol, HDL- and LDL-cholesterol, triglycerides, free fatty acids, waist and hip circumference, heart rate, systolic and diastolic blood pressure. Furthermore, we evaluated the incidence of a metabolic syndrome and investigated the metabolic changes in depressed patients with and without a metabolic syndrome. We found 42.1% of patients to fulfil the criteria for a metabolic syndrome. Overall, reboxetine was well tolerated with essentially no side effects during the observation period. A 4-week treatment with reboxetine showed a beneficial effect on several metabolic parameters that was independent from treatment outcome and could therefore theoretically be attributed to the pharmacological profile of the drug. Due to the preliminary character of the present investigation, no conclusions about the clinical efficacy of reboxetine can be drawn.

Association between a serotonin transporter length polymorphism and primary insomnia.

STUDY OBJECTIVE: To test the hypothesis that a 44-base-pair insertion/deletion polymorphism in the 5' regulatory region of the serotonin transporter gene (5-HTTLPR) is associated with primary insomnia. DESIGN: Association study. SETTING: Sleep laboratory at the Central Institute of Mental Health, Mannheim, Germany. PATIENTS: 157 patients with primary insomnia and 827 healthy controls. INTERVENTIONS: N/A. MEASUREMENT AND RESULTS: We found the short (s-) allele of the 5-HTTLPR to be significantly more frequent in patients suffering from insomnia than in control individuals (47.1% vs. 39.9%: OR = 1.34). CONCLUSIONS: This finding contributes to the understanding of the pathophysiology of primary insomnia and suggests a biological basis between the prevalent comorbidity of primary insomnia and other psychiatric disorders.

Restless legs syndrome: evidence for nocturnal hypothalamic-pituitary-adrenal system activation.

Epidemiological studies consistently point to a relationship between restless legs syndrome (RLS) and cardiovascular disease. The mechanism underlying this association is unclear. Activation of the hypothalamic-pituitary-adrenal (HPA) system has been shown to contribute to the metabolic syndrome and an enhanced cardiovascular risk. We investigated cortisol levels as an indicator of HPA system activity in RLS during the nighttime, when RLS symptoms are at their maximum. We assessed nocturnal urinary cortisol excretion in 73 patients with RLS and 34 healthy controls, controlling for age and gender. Urine sampling was paralleled by polysomnographic recordings. We found significantly enhanced nocturnal cortisol excretion in RLS, demonstrating nocturnal HPA system overactivity in RLS. HPA system overactivity is a possible mechanism contributing to the enhanced load of cardiovascular disease in RLS patients. Nocturnal cortisol release showed weak correlations with some polysomnographic parameters of disturbed sleep, making a potential contribution of RLS-induced sleep disruption to HPA system activation conceivable.

Antidepressant treatment with mirtazapine, but not venlafaxine, lowers cortisol concentrations in saliva: a randomised open trial.

Lowering the concentrations of free cortisol in depressed patients may be an important prerequisite to prevent glucocorticoid-related sequelae of depression. We tested the hypothesis that the hypothalamus-pituitary-adrenal (HPA) system-dampening effects of venlafaxine and mirtazapine differ. We compared the course of morning (08.00h) and afternoon saliva cortisol (16.00h) in 42 mirtazapine- and 45 venlafaxine-treated depressed patients during a 1-week wash-out and a 4-week treatment period in a randomised open trial. Mirtazapine lowered afternoon cortisol from week 1 to 4. In contrast, during the course of the entire treatment period, venlafaxine did not attenuate saliva cortisol concentrations. Treatment effects of mirtazapine on cortisol concentrations did not differ in remitters and non-remitters to treatment. High baseline cortisol concentrations, on the other hand, were related to an unfavourable course during venlafaxine treatment and patients remitting during venlafaxine treatment had significantly lower afternoon cortisol concentrations in saliva, when compared to non-remitting patients. Thus, mirtazapine and venlafaxine show different effects on HPA system activity as measured by saliva cortisol. This may be of relevance with regard to physical sequelae of depression.

Matrix metalloproteinases in peripheral blood and cerebrospinal fluid in patients with Alzheimer's disease.

BACKGROUND: Deposition of amyloid beta in senile plaques and in cerebral blood vessels is one hallmark of the pathogenesis of Alzheimer's disease (AD). The ability of several matrix metalloproteinases (MMPs) to degrade amyloid precursor protein leading to aggregation of amyloid beta, as well as the increased expression of MMPs in post mortem brain tissue of Alzheimer's patients, indicate that MMPs play an important role in the pathogenesis of AD. METHODS: We investigated levels of MMP-2,-3,-9 and -10 in plasma and cerebrospinal fluid (CSF) of AD patients (n = 14) by gelatin and casein zymography. Comparisons between AD patients and controls relative to levels of MMP-2, MMP-3, MMP-9, and MMP-10 were made with Wilcoxon rank statistics. Pearson correlations were computed as measures of association. RESULTS: MMP-3 in AD was significantly elevated in plasma (p = 0.006) and there was a trend towards increase in CSF (p = 0.05). MMP-2 in CSF of AD patients was significantly decreased (p = 0.02) while levels in plasma remained unchanged. MMP-9 and MMP-10 could not be detected in CSF; MMP-10 was unchanged in plasma, but MMP-9 was significantly decreased (p = 0.02). CONCLUSIONS: These findings constitute further evidence for the important role of MMPs in the pathogenesis of AD.

Enhanced Vigilance Stability during Daytime in Insomnia Disorder.

Central nervous hyperarousal is as a key component of current pathophysiological concepts of chronic insomnia disorder. However, there are still open questions regarding its exact nature and the mechanisms linking hyperarousal to sleep disturbance. Here, we aimed at studying waking state hyperarousal in insomnia by the perspective of resting-state vigilance dynamics. The VIGALL (Vigilance Algorithm Leipzig) algorithm has been developed to investigate resting-state vigilance dynamics, and it revealed, for example, enhanced vigilance stability in depressive patients. We hypothesized that patients with insomnia also show a more stable vigilance regulation. Thirty-four unmedicated patients with chronic insomnia and 25 healthy controls participated in a twenty-minute resting-state electroencephalography (EEG) measurement following a night of polysomnography. Insomnia patients showed enhanced EEG vigilance stability as compared to controls. The pattern of vigilance hyperstability differed from that reported previously in depressive patients. Vigilance hyperstability was also present in insomnia patients showing only mildly reduced sleep efficiency. In this subgroup, vigilance hyperstability correlated with measures of disturbed sleep continuity and arousal. Our data indicate that insomnia disorder is characterized by hyperarousal at night as well as during daytime.

Association of Locomotor Activity During Sleep Deprivation Treatment With Response.

Disrupted circadian rhythms and sleep patterns are frequently observed features of psychiatric disorders, and especially mood disorders. Sleep deprivation treatment (SD) exerts rapid but transient antidepressant effects in depressed patients and has gained recognition as a model to study quick-acting antidepressant effects. It is of interest how locomotor activity patterns during SD might be associated with and potentially predict treatment response. The present study is an analysis of locomotor activity data, previously collected over a 24 h period, to examine the night of SD (Trautmann et al. 2018) as mood disorder patients suffering from a depressive episode (n = 78; after exclusions n = 59) underwent SD. In this exploratory analysis, the associations between response to SD, locomotor activity, and subjective mood during the 24 h period of SD were explored. Higher levels of activity overall were observed in non-responders (n = 18); in particular, non-responders moved more during the evening of SD until midnight and remained high thereafter. In contrast, activity in responders (n = 41) decreased during the evening and increased in the morning. Subjective mood was not found to be associated with locomotor activity. The window of data available in this analysis being limited, additional data from before and after the intervention are required to fully characterize the results observed. The present results hint at the possible utility of locomotor activity as a predictor and early indicator of treatment response, and suggest that the relationship between SD and locomotor activity patterns should be further investigated.