The Efficacy of a Multimodal Bedroom-Based 'Smart' Alarm System on Mitigating the Effects of Sleep Inertia.

Previous work has demonstrated the modest impact of environmental interventions that manipulate lighting, sound, or temperature on sleep inertia symptoms. The current study sought to expand on previous work and measure the impact of a multimodal intervention that collectively manipulated light, sound, and ambient temperature on sleep inertia. Participants slept in the lab for four nights and were awoken each morning by either a traditional alarm clock or the multimodal intervention. Feelings of sleep inertia were measured each morning through Psychomotor Vigilance Test (PVT) assessments and ratings of sleepiness and mood at five time-points. While there was little overall impact of the intervention, the participant's chronotype and the length of the lighting exposure on intervention mornings both influenced sleep inertia symptoms. Moderate evening types who received a shorter lighting exposure (≤15 min) demonstrated more lapses relative to the control condition, whereas intermediate types exhibited a better response speed and fewer lapses. Conversely, moderate evening types who experienced a longer light exposure (>15 min) during the intervention exhibited fewer false alarms over time. The results suggest that the length of the environmental intervention may play a role in mitigating feelings of sleep inertia, particularly for groups who might exhibit stronger feelings of sleep inertia, including evening types.

The importance of residential dusk and dawn light exposure for sleep quality, health, and well-being.

Light exposure during twilight plays a critical role in the entrainment of the human circadian system. People are most often at home during dusk and dawn, and light exposure at home - either natural or from electric light - may therefore contribute substantially to sleep and well-being. However, very little research has focused on the effects of home lighting on sleep and well-being, and even less research has investigated the effects of light exposure during twilight. Therefore, a literature study was performed to collect studies on light exposure at home during dusk and dawn. Studies looking at light exposure during dusk and dawn have focused on either electric light intervention (i.e., dusk and dawn simulation) at home or in the laboratory or daylight exposure in the bedroom (i.e., the presence and type of curtains in the bedroom). Most research has focused on dawn simulation during the darker months of the year, often using sunrise alarms. In general, study results pointed to the importance of twilight light exposure at home for sleep and well-being. These results may depend on the characteristics of the user, such as age or chronotype.

Behavioural effects of light intervention in people with Korsakoff Syndrome: A pilot study.

Korsakoff Syndrome (KS) is commonly associated with behavioural symptoms such as agitation, apathy, and disinhibition. People with KS often reside in long-term care facilities, which reduces their exposure to natural light. Little is known regarding positive effects of light intervention in KS. Our objective was to evaluate the influence of a dawn simulation therapy on behavioural symptoms in KS. 38 patients residing in a 24-hour care facility were exposed for 6 weeks to a dawn simulation system in their bedrooms, which gradually increased from 0 lux to 290 lux. Behavioural symptoms were measured over 9 weeks. Weeks 1-3 consisted of the baseline phase and weeks 3-9 consisted of the light intervention phase. Our study showed that total severity of neuropsychiatric symptoms was less prominent during light intervention. More specifically, a decrease on the apathy, disinhibition, behaviour at night and appetite and eating behaviour subscales was found during the light intervention phase compared to the baseline phase. Additionally, a significant effect was found on decreasing emotional distress for caregivers. Results suggest that light intervention therapy has a positive effect on reducing behavioural symptoms in KS as well as the levels of stress experienced by the patients' caregivers.

Light Intervention Effects on Circadian Activity Rhythm Parameters and Nighttime Sleep in Dementia Assessed by Wrist Actigraphy: A Systematic Review and Meta-Analysis.

BACKGROUND AND OBJECTIVES: Persons with dementia often show circadian rhythm disturbances and sleep problems. Timed light exposure seems to be a promising nonpharmacological treatment option. In this review, meta-analyses were run on light effects on circadian activity rhythm parameters in persons with dementia measured with wrist actimetry. Furthermore, we update a Cochrane review, published in 2014, on actigraphically measured light effects in nighttime sleep parameters in persons with dementia. RESEARCH DESIGN AND METHODS: Four electronic databases were searched for randomized controlled trials. Effects in meta-analyses were summarized by using mean differences and 95% confidence intervals. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to assess the risk of bias and registered the review protocol (PROSPERO: CRD42020149001). RESULTS: Thirteen trials met inclusion criteria, and either utilized light therapy devices, ambient room lighting systems, or dawn-dusk interventions. Eleven of these studies were subjected to meta-analyses. They did not reveal significant light effects on circadian activity parameters: amplitude (p = .62; n = 313), acrophase (p = .34; n = 313), intradaily variability (p = .51; n = 354), and interdaily stability (p = .38; n = 354). Furthermore, no light effects were found on sleep parameters: total sleep duration (p = .53; n = 594), sleep efficiency (p = .63; n = 333), wake after sleep onset (p = .95; n = 212), and sleep onset latency (p = .26; n = 156). Subgroup analyses, pooling data from 3 studies including persons with Alzheimer's dementia, also did not show light effects on circadian activity and sleep parameters. The overall risk of bias of included studies was high. DISCUSSION AND IMPLICATIONS: There is insufficient evidence for actigraphically measured circadian light effects in persons with dementia. More high-quality research is needed to recommend the application of adjunctive light.

Light therapies to improve sleep in intrinsic circadian rhythm sleep disorders and neuro-psychiatric illness: A systematic review and meta-analysis.

Circadian dysregulation causes sleep disturbance and impacts quality of life and functioning. Some interventions target circadian entrainment through modifying light exposure, but existing reviews of light interventions for sleep improvement include few studies in psychiatric populations. We examined effect of light interventions on sleep quality, duration and timing, and effect moderators. We included controlled studies in intrinsic circadian rhythm disorders (such as advanced or delayed sleep) and in neuropsychiatric disorders with assumed high prevalence of circadian dysregulation (such as affective and psychotic disorders). Articles were identified through database searching: 40 studies reporting 49 relevant intervention comparisons met inclusion criteria. Meta-analysis showed improvements in sleep continuity (ES = -0.23, p = 0.000), self-reported sleep disturbance (ES = -0.32, p = 0.014), and advancement of delayed sleep timing (ES = -0.34, p = 0.010). Although the small number of studies limited meta-regression, evening light avoidance was associated with greater increase in total sleep time. Effects of light on sleep and circadian outcomes have received limited attention in studies in psychiatric disorders, but results were promising in these groups. These findings invite further refinement and testing of light interventions to improve sleep in psychiatric disorders, with improved assessment and specification of problems, and the development and implementation of light schedule interventions for delayed sleep.

Dawn simulation vs. bright light in seasonal affective disorder: Treatment effects and subjective preference.

BACKGROUND: Studies comparing the efficacy of dawn simulation to conventional bright light for the treatment of seasonal affective disorder (in parallel groups) have yielded conflicting results. This crossover study investigated treatment outcomes and long-term treatment preference. METHODS: Forty winter depressives were treated for a week with bright light (4.300lx for 30-45min shortly after awakening) or dawn simulation (gradually increasing light during the last 30min of sleep achieving 100lx before alarm beep, with the dawn simulator placed closer to the open eyes for a further 15min: 250lx). The depression level was self-rated using SIGH-SAD-SR. RESULTS: Depression scores reduced similarly following bright light and dawn simulation: for 43.8% and 42.2% (medians), respectively; efficacy ratio was 23:17. The preference was also similar (21:19). Among those who preferred bright light, the most common reason was that they perceived the bright light to be more effective (19/21; it was more effective, p=0.0096; this subgroup tended to have more severe depression) and ease of use (6/21). Among those who preferred the dawn simulator, the reasons were a more "natural" action (9/19), device compactness and/or time-saving (10/19) and in 4 cases where bright light caused eyestrain. LIMITATIONS: Not overhead naturalistic light for dawn simulation, self-rating of depression. CONCLUSIONS: Dawn simulation is similarly effective to bright light in the treatment of winter depression. Patients with more severe depression tended to report greater improvement with bright light; in such cases, this would outweigh the non-clinical advantages of dawn simulation.

Dawn simulation light impacts on different cognitive domains under sleep restriction.

Chronic sleep restriction (SR) has deleterious effects on cognitive performance that can be counteracted by light exposure. However, it is still unknown if naturalistic light settings (dawn simulating light) can enhance daytime cognitive performance in a sustainable matter. Seventeen participants were enrolled in a 24-h balanced cross-over study, subsequent to SR (6-h of sleep). Two different light settings were administered each morning: a) dawn simulating light (DsL; polychromatic light gradually increasing from 0 to 250 lx during 30 min before wake-up time, with light around 250 lx for 20 min after wake-up time) and b) control dim light (DL; <8 lx). Cognitive tests were performed every 2 h during scheduled wakefulness and questionnaires were completed hourly to assess subjective mood. The analyses yielded a main effect of "light condition" for the motor tracking task, sustained attention to response task and a working memory task (visual 1 and 3-back task), as well as for the Simple Reaction Time Task, such that participants showed better task performance throughout the day after morning DsL exposure compared to DL. Furthermore, low performers benefited more from the light effects compared to high performers. Conversely, no significant influences from the DsL were found for the Psychomotor Vigilance Task and a contrary effect was observed for the digit symbol substitution test. No light effects were observed for subjective perception of sleepiness, mental effort, concentration and motivation. Our data indicate that short exposure to artificial morning light may significantly enhance cognitive performance in a domain-specific manner under conditions of mild SR.

Antidepressant chronotherapeutics for bipolar depression.

Chronotherapeutics refers to treatments based on the principles of circadian rhythm organization and sleep physiology, which control the exposure to environmental stimuli that act on biological rhythms, in order to achieve therapeutic effects in the treatment of psychiatric conditions. It includes manipulations of the sleep-wake cycle such as sleep deprivation and sleep phase advance, and controlled exposure to light and dark. The antidepressant effects of chronotherapeutics are evident in difficult-to-treat conditions such as bipolar depression, which has been associated with extremely low success rates of antidepressant drugs in naturalistic settings and with stable antidepressant response to chronotherapeutics in more than half of the patients. Recent advances in the study of the effects of chronotherapeutics on neurotransmitter systems, and on the biological clock machinery, allow us to pinpoint its mechanism of action and to transform it from a neglected or "orphan" treatment to a powerful clinical instrument in everyday psychiatric practice.

La cronoterapia se refiere a los tratamientos basados en fas principios de la organización del ritmo circadiano y de la fisiología del sueño, mediante el control de la exposición a los estímulos ambientales que actúan sobre los ritmos biológicos con el fin de conseguir efectos terapéuticos en el tratamiento de los cuadros psiquiátricos. Esta terapia incluye manipulaciones del ciclo sueño-vigilia como la privación de sueño y el avance de fase, junto con la exposición controlada a la luz y a la oscuridad. Los efectos antidepresivos de la cronoterapia son evidentes en cuadros de difícil tratamiento como la depresión bipolar, la cual se ha asociado con resultados de éxito extremadamente bajos para los fármacos antidepresivos en estudios naturalísticos y con una respuesta antidepresiva estable a la cronoterapia en más de la mitad de los pacientes. Avances recientes en el estudio de los efectos de la cronoterapia en los sistemas de neurotransmisión y en la maquinaria del reloj biológico, permiten identificar su mecanismo de acción y transformarla desde un rechazo o un "tratamiento huérfano" a un poderoso instrumento clínico en la práctica psiquiátrica cotidiana.

La chronothérapie se rapporte aux traitements dont les principes reposent sur l'organisation des rythmes circadiens et la physiologie du sommeil, qui contrôlent l'exposition aux stimuli environnementaux agissant sur les rythmes biologiques, afin de pouvoir traiter les pathologies psychiatriques. Elle comprend des manipulations du cycle veille-sommeil comme la privation de sommeil et l'avance de phase du sommeil ainsi qu'une exposition contrôlée à la lumière et à la nuit. Les effets antidépresseurs de la chronothérapie sont évidents dans des pathologies difficiles à traiter comme la dépression bipolaire, qui a été associée à des taux de succès extrêmement faibles des antidépresseurs dans les échantillons naturalistes et à une réponse antidépressive stable à la chronothérapie chez plus de la moitié des patients. Des progrès récents dans l'étude des effets de la chronothérapie sur les neurotransmetteurs et sur l'horloge biologique nous permettent d'identifier son mécanisme d'action et de faire de ce traitement « orphelin ¼ ou négligé un instrument clinique puissant en pratique psychiatrique quotidienne.

Effect of Dawn Simulation on Difficulty Awakening in the Morning and Daytime Sleepiness in Adolescents with Delayed Sleep Phase Syndrome / 신경정신의학

OBJECTIVES: Delayed sleep phase syndrome (DSPS) is characterized by difficulties in falling asleep and waking up at a desired time. Dawn simulation is a technique using a light that gradually increases in intensity before awakening in the morning, to imitate a natural sunrise. It has been found to be effective in decreasing both morning drowsiness and difficulty in awakening as well as treating symptoms of seasonal affective disorder. The aim of this study was to determine whether dawn simulation is helpful in decreasing difficulty in morning awakening and daytime sleepiness in adolescents with DSPS. METHODS: Twelve adolescents with DSPS participated in a 2-week dawn simulation trial. Each subject self-assessed level of difficulty in awakening, morning drowsiness and daytime sleepiness during a 2-week baseline period and a following 2-week trial period with dawn simulator. Subjects used Stanford Sleepiness Scale (SSS) for measuring morning drowsiness and Epworth Sleepiness Scale (ESS) for measuring daytime sleepiness. Difficulty in awakening was assessed by a single-item questionnaire. RESULTS: Dawn simulation trial decreased morning drowsiness (p=0.016) and daytime sleepiness (p=0.013) significantly compared to baseline. It also seemed to improve difficulty in awakening, but the effect was not statistically significant (p=0.092). CONCLUSION: Dawn simulation may help waking up in the morning and may improve daytime functioning by deceasing both morning drowsiness and daytime sleepiness in adolescents with DSPS.