4,165 research outputs found
Ultradian and circadian modulation of dream recall: EEG correlates and age effects
No full textpeer reviewe
Sleep disorders and suicidal ideation in patients with depressive disorder.
No full textpeer reviewedAn intrinsic association between suicidal ideation and sleep disorders in patients with depressive disorder has been observed in recent studies. This study was conducted in order to examine the relationship between suicidal ideation and sleep disorders, such as insomnia and excessive sleepiness, in outpatients with major depressive disorder. Seventy patients with diagnoses of major depressive disorder were interviewed and assessed with the Sleep Habits Questionnaire and the Beck Scale for Suicidal Ideation (SSI). Data analyses were performed through descriptive analysis, Students t-test, Chi-square test and logistic regression model, with a statistical significance of 5%. In this study, depressed patients had high SSI scores (6.12+/-2.67), particularly for active suicidal ideation (1.61+/-0.39) and specific plans for suicide components (1.51+/-0.40). Depressed patients with insomnia had significantly higher SSI scores (7.39+/-2.84), in relation to patients with excessive sleepiness (3.68+/-1.73). Furthermore it was observed that insomniac patients had significantly higher scores on the following components: active suicide ideation, specific plans for suicide and previous suicide attempts. The results of multivariate analysis showed that only insomnia had a significant association with suicidal ideation. Thus, sleep disturbances, particularly insomnia, should be considered in the assessment of suicidal risk in outpatients with depressive disorder
Excessive daytime sleepiness in patients with depressive disorder Sonolência diurna excessiva em pacientes com transtorno depressivo
No full textOBJECTIVE: To evaluate excessive daytime sleepiness in patients with depressive disorder and to examine its association with the severity of depression and suicidal ideation. METHOD: Seventy patients were interviewed and assessed by the Epworth Sleepiness Scale (ESS), the Beck Depression Inventory (BDI) and the Beck Scale for Suicidal Ideation (SSI). Descriptive analysis, Pearson correlations and Student's t-test were used for data analyses. RESULTS: Most of the patients (57.1%) obtained high scores on the ESS. Correlation was positive and strongly significant between ESS scores and BDI scores, as well as between ESS scores and SSI scores. Patients with high ESS scores obtained higher mean BDI and SSI scores in comparison to patients with lower ESS scores. Significant differences (p 10) and lower (OBJETIVO: Avaliar a incidência de sonolência diurna excessiva em pacientes com transtorno depressivo e examinar sua associação com a gravidade do quadro depressivo e ideação suicida. MÉTODO: Setenta pacientes foram entrevistados e avaliados através da Escala de Sonolência de Epworth (ESE), da Escala de Depressão de Beck BD e da Escala de Ideação Suicida de Beck (EIS). Análises descritivas, análise de correlação de Pearson e teste-t de Student foram utilizados para a análise dos dados. RESULTADOS: A maioria dos paciente (57,1%) apresentaram altas pontuações na ESE. Houve correlações positivas e fortes entre scores da ESE e BD e entre scores da ESE e EIS. Pacientes com altas pontuações na ESE obtiveram escores na BD e na EIS mais elevados do que os pacientes com baixos escores de ESE. Houve diferenças significativas (p 10) na ESE, em relação às pontuações totais das ESE, EDB e EIS. CONCLUSÕES: A sonolência diurna excessiva foi freqüente nos pacientes e significativamente associada a maior gravidade da depressão e ideação suicida. Desta maneira, é necessária uma cuidadosa investigação da sonolência diurna excessiva em pacientes deprimidos durante a avaliação clínica
Chronobiology, excessive daytime sleepiness and depression: Is there a link?
No full textThe complaint of excessive daytime sleepiness (EDS), commonly encountered in clinical practice, may arise from a variety of psychiatric disorders, most importantly depression. Even though EDS frequently leads depressed patients to seek medical assistance, it is commonly under-evaluated and under-diagnosed. Therefore, a comprehensive understanding and management of EDS is essential in the clinical assessment of depression. Within a theoretical framework, a chronobiological approach may shed new light on the complex interaction of EDS and depression. In this review, studies on EDS and depression are summarized and discussed within the context of circadian and sleep regulatory mechanisms. Furthermore, potential chronobiological therapeutic strategies are proposed to address some of the unmet needs in the treatment of EDS and depression
Effects of circadian misalignment on cognition in chronic shift workers.
No full textShift work is associated with increased human operational errors, presumably due to the circadian timing system that inhibits optimal cognitive function during the night. Circadian misalignment, which is the misalignment between the circadian pacemaker and behavioral/environmental cycles, impairs cognitive performance in non-shift workers. However, it remains uncertain whether the adverse cognitive consequences of circadian misalignment are also observed in chronic shift workers. Thus, we investigated the effects of circadian misalignment on cognitive performance in chronic shift workers. Using a randomized, cross-over design that simulated day shift work (circadian alignment) and night shift work (circadian misalignment), we show that circadian misalignment increases cognitive vulnerability on sustained attention, information processing and visual-motor performance, particularly after more than 10 hours of scheduled wakefulness. Furthermore, their increased levels of subjective sleepiness and their decreased sleep efficiency were significantly associated with impaired sustained attention and visual-motor performance. Our data suggest that circadian misalignment dramatically deteriorates cognitive performance in chronic shift workers under circadian misalignment. This increased cognitive vulnerability may have important safety consequences, given the increasing number of nighttime jobs that crucially rely on the availability of cognitive resources
Circadian and ultradian NREM-REM sleep modulation of dream recall : effects of age and spectral activity
No full textThis thesis deals with the electrophysiological correlates of sleep prior to dream recall and the age-related effects on dream processing. The dual NREM/REM sleep cycle and the circadian modulation of REM sleep sum to generate dream processing. However, little is known about the age-related effects on dream recall during both NREM and REM sleep, which comprises the first aim of this thesis. To address this question, seventeen young (20-31 years) and 15 older (57-74 years) healthy volunteers underwent continuous polysomnography recording and hormonal assessments during a 40-h multiple nap protocol (150 minutes of wakefulness and 75 minutes of sleep; 10 naps in total) under constant routine conditions. The analysis of NREM/REM sleep prior to dream recall focused on the last 15 minutes of each nap prior to dream recall. Number of dreams, dream recall and the emotional aspect of dreaming was investigated using the sleep mentation questionnaire. The results indicate that older participants had less dream recall after both NREM and REM sleep, although no differences were observed between the age-groups with respect to the emotional domain of dreaming. Interestingly, older volunteers had fewer dreams after naps scheduled during the biological day (outside the time window of melatonin secretion), which was closely associated with the circadian rhythm of REM sleep. This implies that aging can be associated to decreased amplitude in the circadian modulation of REM sleep, with repercussions on dream recall.
Since dreaming crucially relies on the ultradian NREM/REM sleep, it is very likely that differences in the spectral composition of sleep prior to dreaming may pinpoint the cortical networks associated to dream generation. Surprisingly, frequency and regional specific differences in EEG activity prior to dreaming remains both controversial and with mixed results, due to the use of different sleep recordings and dream assessments. To answer this issue, NREM/REM sleep EEG power density associated with and without dream recall was investigated in young participants. NREM sleep was associated with lower EEG power density for dream recall in frontal delta and centro-parietal sigma activity, while REM sleep was associated with low frontal alpha activity, and with high occipital alpha and beta activity. Thus, specific EEG frequency- and topography changes can modulate differences between dream recall and no recall after NREM and REM sleep awakening.
In the next logical step, we investigated how age-related changes in sleep structure can impact on dream processing, an issue that remains largely unknown. During NREM sleep prior to dream recall, older participants had higher frontal EEG delta activity and higher centro-parietal sigma activity than the young volunteers. Contrariwise, before no recall, older participants had less frontal-central delta activity and less sigma activity in frontal, central and parietal derivations than the young participants. REM sleep was associated to age-related changes, such that older participants had less frontal-central alpha and beta activity, irrespective of dream recall and no recall. Taken together, age-related differences in dream recall seem to be directly associated to specific frequency and topography EEG activity patterns, particularly during NREM sleep. Thus, aging can result in specific changes for dream processing, most likely through its effects on sleep. The results in this thesis indicate that the circadian and ultradian NREM/REM sleep modulation on dream recall can help to better understand the mechanistic framework of this complex cognitive process
Association of Intraocular Cataract Lens Replacement With Circadian Rhythms, Cognitive Function, and Sleep in Older Adults.
No full textImportance
Cataract is associated with a progressive decline in light transmission due to the clouding and yellowing of the natural crystalline lens. While the downstream effects of aging lenses include long-term disruption of circadian rhythms, cognitive function, and sleep regulation, it remains unknown whether there is an association of intraocular cataract lens (IOLs) replacement with circadian rhythms, cognition, and sleep.
Objective
To test whether IOL replacement (blue blocking [BB] or ultraviolet [UV] only blocking) in older patients with previous cataract is associated with the beneficial light effects on the circadian system, cognition, and sleep regulation.
Design, Setting, and Participants
Cross-sectional study at the Centre for Chronobiology, University of Basel in Switzerland from February 2012 to April 2014, analyzed between June 2012 and September 2018. Sixteen healthy older controls and 13 patients with previous cataract and IOL replacement participated without medication and no medical and sleep comorbidities.
Exposures
Three and a half hours of prior light control (dim-dark adaptation), followed by 2 hours of evening blue-enriched (6500 K) or non-blue-enriched light exposure (3000 K and 2500 K), 30 minutes in dim post-light exposure, 8 hours of sleep opportunity, and 2 hours of morning dim light following sleep.
Main Outcomes and Measures
Salivary melatonin, cognitive tests, and sleep structure and electroencephalographic activity to test the association of IOLs with markers of circadian rhythmicity, cognitive performance, and sleep regulation, respectively.
Results
The participants included 16 healthy older controls with a mean (standard error of the mean [SEM]) of 63.6 (5.6) years; 8 women and 13 patients with previous cataract (mean [SEM] age, 69.9 [5.2] years; 10 women); 5 patients had UV IOLs and 8 had BB IOLs. Patients with previous cataract and IOLs had an attenuated increase in melatonin levels during light exposure (mean [SEM] increase in the BB group: 23.3% [2.6%] and in the UV lens group: 19.1% [2.1%]) than controls (mean [SEM] increase, 48.8% [5.2%]) (difference between means, 27.7; 95% CI, 15.4%-41.7%; P < .001). Cognitive function, indexed by sustained attention performance, was improved in patients with UV lens (mean [SEM], 276.9 [11.1] milliseconds) compared with patients with BB lens (mean [SEM], 348.3 [17.8] milliseconds) (difference between means, 71.4; 95% CI, 29.5%-113.1%; P = .002) during light exposure and in the morning after sleep. Patients with UV lens had increased slow-wave sleep (mean [SEM] increase, 13% [3.4%]) compared with controls (mean [SEM] increase, 5.2% [0.8%]) (percentage of total sleep time; difference between means, 7.9; 95% CI, 2.4%-13.4%; P = .02) and frontal non-rapid eye movement slow-wave activity (0.75-4.5 Hz) during the first sleep cycle (mean [SEM], 79.9 [13.6] μV2/Hz) compared with patients with BB lens (mean [SEM], 53.2 [10.7] μV2/Hz) (difference between means, 26.7; 95% CI, 9.2-48.9; P = .03).
Conclusions and Relevance
These in-laboratory empirical findings suggest that optimizing the spectral lens transmission in patients with previous cataract may minimize the adverse age-related effects on circadian rhythms, cognition, and sleep
Daily circadian misalignment impairs human cognitive performance task-dependently
No full textShift work increases the risk for human errors, such that drowsiness due to shift work has contributed to major industrial disasters, including Space Shuttle Challenger, Chernobyl and Alaska Oil Spill disasters, with extraordinary socio-economical costs. Overnight operations pose a challenge because our circadian biology inhibits cognitive performance at night. Yet how the circadian system modulates cognition over multiple days under realistic shift work conditions remains to be established. Importantly, because task-specific cognitive brain regions show different 24-h circadian dynamics, we hypothesize that circadian misalignment impacts cognition task-dependently. Using a biologically-driven paradigm mimicking night shift work, with a randomized, cross-over design, we show that misalignment between the circadian pacemaker and behavioral/environmental cycles increases cognitive vulnerability on sustained attention, cognitive throughput, information processing and visual-motor performance over multiple days, compared to circadian alignment (day shifts). Circadian misalignment effects are task-dependent: while they acutely impair sustained attention with recovery after 3-days, they progressively hinder daily learning. Individuals felt sleepier during circadian misalignment, but they did not rate their performance as worse. Furthermore, circadian misalignment effects on sustained attention depended on prior sleep history. Collectively, daily circadian misalignment may provide an important biological framework for developing countermeasures against adverse cognitive effects in shift workers.Version of Recor
Impact of mental stress, the circadian system and their interaction on human cardiovascular function.
No full textThe risk for adverse cardiovascular events (e.g., myocardial infarction, sudden cardiac death) peaks in the morning, possibly due to the effects of the endogenous circadian system on cardiovascular risk factors, or the occurrence in the morning of specific triggers, such as mental stress. To assess any interacting effects on cardiovascular function of mental stress and the circadian system, 12 healthy adults underwent a 240-h protocol with all measurements and behaviors scheduled evenly across the circadian cycle. Mental stress was repeatedly induced by performance-motivated serial addition tasks. Cardiovascular measures included hemodynamic function (heart rate, blood pressure), circulating catecholamines (epinephrine, norepinephrine), and estimates of sympathovagal balance and cardiac vagal modulation derived from heart rate variability analyses. Mental stress increased hemodynamic function, sympathovagal balance and epinephrine, and decreased cardiac vagal modulation. Endogenous circadian variation occurred in all cardiovascular measures: sympathovagal balance peaked in the circadian morning (∼9 AM), cardiac vagal modulation in the circadian night (∼4 AM), and heart rate and circulating catecholamines in the late circadian morning/early afternoon (∼12 PM). Importantly, the effects of mental stress and the endogenous circadian system on cardiovascular function occurred in conjunction, such that mental stress in the circadian morning caused greatest sympathovagal balance. This summation of effects could contribute to the increased morning cardiovascular vulnerability
sj-pdf-1-lrt-10.1177_14771535221078765 – Supplemental Material for Influence of evening light exposure on polysomnographically assessed night-time sleep: A systematic review with meta-analysis
No full textSupplemental Material, sj-pdf-1-lrt-10.1177_14771535221078765 for Influence of evening light exposure on polysomnographically assessed night-time sleep: A systematic review with meta-analysis by C Cajochen, O Stefani, I Schöllhorn, D Lang and SL Chellappa in Lighting Research & Technology</p
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