Dark therapy for bipolar disorder using amber lenses for blue light blockade

Therapeutic sleep deprivation for major depressive disorder: A randomized controlled trial

BACKGROUND

Major depressive disorder (MDD) is treated primarily using antidepressant drugs, but clinical effects may be delayed for weeks to months. This study investigated the efficacy of brief therapeutic sleep deprivation (TSD) for inducing rapid improvements in MDD symptoms.

METHODS

From November 2020 to February 2023, 54 inpatients with MDD were randomly allocated to TSD and Control groups. The TSD group (23 cases) remained awake for 36 h, while the Control group (31 cases) maintained regular sleep patterns. All participants continued regular drug therapy. Mood was assessed using the 24-item Hamilton Depression Scale (HAMD-24) at baseline and post-intervention in both groups. In the TSD group, the Visual Analogue Scale (VAS) was utilized to evaluate subjective mood during and after the intervention. Cognitive function was assessed at baseline and post-intervention using the Montreal Cognitive Assessment (MoCA). Objective sleep parameters were recorded in the TSD group by polysomnography. The follow-up period spanned one week.

RESULTS

HAMD-24 scores did not differ between groups at baseline or post-intervention. However, the clinical response rate was 34.8 % higher in the TSD group on day 3 post-intervention compared to the Control group (3.2 %), but not sustained by day 7. Moreover, responders demonstrated a faster improvement in the VAS score during TSD than non-responders (p = 0.047). There were no significant differences in MoCA scores or objective sleep parameters between the groups.

LIMITATIONS

Small sample size and notable attrition rate.

CONCLUSIONS

Therapeutic sleep deprivation can rapidly improve MDD symptoms without influencing sleep parameters or cognitive functions. Assessment of longer-term effects and identification of factors predictive of TSD response are warranted.

Does circadian dysrhythmia drive the switch into high- or low-activation states in bipolar I disorder?

OBJECTIVES

Emerging evidence suggests a role of circadian dysrhythmia in the switch between "activation" states (i.e., objective motor activity and subjective energy) in bipolar I disorder.

METHODS

We examined the evidence with respect to four relevant questions: (1) Are natural or environmental exposures that can disrupt circadian rhythms also related to the switch into high-/low-activation states? (2) Are circadian dysrhythmias (e.g., altered rest/activity rhythms) associated with the switch into activation states in bipolar disorder? (3) Do interventions that affect the circadian system also affect activation states? (4) Are associations between circadian dysrhythmias and activation states influenced by other "third" factors?

RESULTS

Factors that naturally or experimentally alter circadian rhythms (e.g., light exposure) have been shown to relate to activation states; however future studies need to measure circadian rhythms contemporaneously with these natural/experimental factors. Actigraphic measures of circadian dysrhythmias are associated prospectively with the switch into high- or low-activation states, and more studies are needed to establish the most relevant prognostic actigraphy metrics in bipolar disorder. Interventions that can affect the circadian system (e.g., light therapy, lithium) can also reduce the switch into high-/low-activation states. Whether circadian rhythms mediate these clinical effects is an unknown but valuable question. The influence of age, sex, and other confounders on these associations needs to be better characterised.

CONCLUSION

Based on the reviewed evidence, our view is that circadian dysrhythmia is a plausible driver of transitions into high- and low-activation states and deserves prioritisation in research in bipolar disorders.

Blue Light Blocking Treatment for the Treatment of Bipolar Disorder: Directions for Research and Practice

Recent results from a small number of clinical studies have resulted in the suggestion that the process of blocking the transmission of shorter-wavelength light (‘blue light’ with a wave length of 450 nm to 470 nm) may have a beneficial role in the treatment of bipolar disorder. This critical review will appraise the quality of evidence so far as to these claims, assess the neurobiology that could be implicated in the underlying processes while introducing a common set of research criteria for the field.

Toward a Digital Future in Bipolar Disorder Assessment: A Systematic Review of Disruptions in the Rest-Activity Cycle as Measured by Actigraphy

BACKGROUND

Disruptions in rest and activity patterns are core features of bipolar disorder (BD). However, previous methods have been limited in fully characterizing the patterns. There is still a need to capture dysfunction in daily activity as well as rest patterns in order to more holistically understand the nature of 24-h rhythms in BD. Recent developments in the standardization, processing, and analyses of wearable digital actigraphy devices are advancing longitudinal investigation of rest-activity patterns in real time. The current systematic review aimed to summarize the literature on actigraphy measures of rest-activity patterns in BD to inform the future use of this technology.

METHODS

A comprehensive systematic review using PRISMA guidelines was conducted through PubMed, MEDLINE, PsycINFO, and EMBASE databases, for papers published up to February 2021. Relevant articles utilizing actigraphy measures were extracted and summarized. These papers contributed to three research areas addressed, pertaining to the nature of rest-activity patterns in BD, and the effects of therapeutic interventions on these patterns.

RESULTS

Seventy articles were included. BD was associated with longer sleep onset latency and duration, particularly during depressive episodes and with predictive value for worsening of future manic symptoms. Lower overall daily activity was also associated with BD, especially during depressive episodes, while more variable activity patterns within a day were seen in mania. A small number of studies linked these disruptions with differential patterns of brain functioning and cognitive impairments, as well as more adverse outcomes including increased suicide risk. The stabilizing effect of therapeutic options, including pharmacotherapies and chronotherapies, on activity patterns was supported.

CONCLUSION

The use of actigraphy provides valuable information about rest-activity patterns in BD. Although results suggest that variability in rhythms over time may be a specific feature of BD, definitive conclusions are limited by the small number of studies assessing longitudinal changes over days. Thus, there is an urgent need to extend this work to examine patterns of rhythmicity and regularity in BD. Actigraphy research holds great promise to identify a much-needed specific phenotypic marker for BD that will aid in the development of improved detection, treatment, and prevention options.

How Smart Is It to Go to Bed with the Phone? The Impact of Short-Wavelength Light and Affective States on Sleep and Circadian Rhythms

Previously, we presented our preliminary results (N = 14) investigating the effects of short-wavelength light from a smartphone during the evening on sleep and circadian rhythms (Höhn et al., 2021). Here, we now demonstrate our full sample (N = 33 men), where polysomnography and body temperature were recorded during three experimental nights and subjects read for 90 min on a smartphone with or without a filter or from a book. Cortisol, melatonin and affectivity were assessed before and after sleep. These results confirm our earlier findings, indicating reduced slow-wave-sleep and -activity in the first night quarter after reading on the smartphone without a filter. The same was true for the cortisol-awakening-response. Although subjective sleepiness was not affected, the evening melatonin increase was attenuated in both smartphone conditions. Accordingly, the distal-proximal skin temperature gradient increased less after short-wavelength light exposure than after reading a book. Interestingly, we could unravel within this full dataset that higher positive affectivity in the evening predicted better subjective but not objective sleep quality. Our results show disruptive consequences of short-wavelength light for sleep and circadian rhythmicity with a partially attenuating effect of blue-light filters. Furthermore, affective states influence subjective sleep quality and should be considered, whenever investigating sleep and circadian rhythms.

Sleep Interventions in the Treatment of Schizophrenia and Bipolar Disorder

Due to the effects of sleep on the central nervous system, it is thought that sleep disorders have a special importance in the onset, course and treatment of psychiatric diseases. Although the negative effects of sleep problems on the occurrence, recurrence and clinical course of psychiatric disorders are well known, it is reported that clinicians do not spend enough time for sleep problems in practice. This may be related to the fact that patients underreport their complaints for various reasons, insufficient examination time, and clinicians' lack of knowledge about the importance of the subject. Pharmacotherapy, psychological and behavioral interventions are options among the therapeutic approaches to sleep problems. But, it seems that clinicians tend to prefer pharmacological approaches for the treatment of sleep problems. However, it is important to choose the appropriate treatment option with considering the method preferred by the patients, who already use many and high doses of pharmacological agents, the nature of the psychiatric disorder and the sleep problem. In this context, chronotherapeutic approaches such as bright light, sleep deprivation, interpersonal relations and social rhythm therapy, and cognitive behavioral therapy techniques adapted for patients with bipolar disorder can be used in the treatment of suitable patients. In this article, the current literature about sleep-related problems observed in patients with schizophrenia and bipolar disorder is reviewed comprehensively with presenting clinical phenotypes and treatment approaches.

Changes of evening exposure to electronic devices during the COVID-19 lockdown affect the time course of sleep disturbances

STUDY OBJECTIVES

During the coronavirus disease 2019 (COVID-19) lockdown, there was a worldwide increase in electronic devices' daily usage. Prolonged exposure to backlit screens before sleep influences the circadian system leading to negative consequences on sleep health. We investigated the relationship between changes in evening screen exposure and the time course of sleep disturbances during the home confinement period due to COVID-19.

METHODS

2,123 Italians (mean age ± standard deviation, 33.1 ± 11.6) were tested longitudinally during the third and the seventh week of lockdown. The web-based survey evaluated sleep quality and insomnia symptoms through the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. The second assessment survey inquired about intervening changes in backlit screen exposure in the two hours before falling asleep.

RESULTS

Participants who increased electronic device usage showed decreased sleep quality, exacerbated insomnia symptoms, reduced sleep duration, prolonged sleep onset latency, and delayed bedtime and rising time. In this subgroup, the prevalence of poor sleepers and individuals reporting moderate/severe insomnia symptoms increased. Conversely, respondents reporting decreased screen exposure exhibited improved sleep quality and insomnia symptoms. In this subgroup, the prevalence of poor sleepers and moderate/severe insomniacs decreased. Respondents preserving screen time habits did not show variations of the sleep parameters.

CONCLUSIONS

Our investigation demonstrated a strong relationship between modifications of evening electronic device usage and time course of sleep disturbances during the lockdown period. Monitoring the potential impact of excessive evening exposure to backlit screens on sleep health is recommendable during the current period of restraining measures due to COVID-19.

Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review

Blue-blocking glasses, also known as amber glasses, are plastic glasses that primarily block blue light. Blue-blocking glasses have been studied as a sleep intervention for insomnia, delayed sleep-phase disorder, shift work, jet lag, and nonpathologic sleep improvement. Blue-blocking glasses have also been studied as a treatment for bipolar disorder, major depression, and postpartum depression. Blue-blocking glasses improve sleep by inducing dim-light melatonin onset by reducing activation of intrinsically photosensitive retinal ganglion cells (ipRGCs) which are most sensitive to blue light and are a major input for circadian regulation; their mechanism for mood regulation is unclear but may be similar to that of dark therapy for bipolar disorder where patients are kept in darkness for an extended period every night. A systematic search of the scientific literature identified a total of 29 experimental publications involving evening wear of blue-blocking glasses for sleep or mood disorders. These consisted of 16 randomized controlled trials (RCTs) published in journals with a total of 453 patients, 5 uncontrolled trials, 1 case series, 1 case study, and 6 abstracts from conference proceedings. Only 1 case study and 1 RCT were for acutely manic patients but both found substantial decreases in manic symptoms with the use of blue-blocking glasses; these give preliminary clinical evidence of efficacy that makes blue-blocking glasses a high-yield intervention to study for bipolar disorder. Findings in the 3 publications for major depression and postpartum depression were heterogeneous and conflicting as to their efficacy. Out of the 24 publications focusing on sleep, there was substantial evidence for blue-blocking glasses being a successful intervention for reducing sleep onset latency in patients with sleep disorders, jet lag, or variable shift work schedules. Given the well-established biological mechanism and clinical research showing that blue-blocking glasses are effective for inducing sleep, they are a viable intervention to recommend to patients with insomnia or a delayed sleep phase.

Effect of evening light exposure on sleep in bipolar disorder: A longitudinal analysis for repeated measures in the APPLE cohort

OBJECTIVE

Sleep disturbance, a core feature of bipolar disorder, is associated with residual mood symptoms, mood episode recurrence and suicide ideation. We investigated the effect of evening light exposure on sleep in patients with bipolar disorder.

METHODS

In this longitudinal analysis, we measured the sleep parameters of 207 outpatients with bipolar disorder using actigraphy at their homes for seven consecutive nights. We measured the white-light illuminance and the irradiance of each wavelength during the 4 hours before each participant's bedtime. We used mixed-effect linear regression analysis for repeated measures to evaluate the effect of evening light exposure on subsequent sleep parameters.

RESULTS

The median white-light illuminance was 25.8 lux (interquartile range, 12.9-50.1 lux). In a multivariable model adjusted for potential confounders, we found higher white-light illuminance to be significantly associated with lower sleep efficiency (per log lux: 95% confidence interval = [-1.328, -0.133]; p = 0.017), prolonged sleep-onset latency (95% confidence interval = [0.006, 0.172]; p = 0.035) and longer wake after sleep onset (95% confidence interval = [1.104, 4.459]; p = 0.001). This effect size was larger in the younger age group (aged < 44 years) stratified by median age. Higher irradiance of the blue wavelength range was significantly associated with longer wake after sleep onset, a result similar to those for the green and red wavelength ranges.

CONCLUSION

We observed significant associations between evening light exposure and subsequent sleep in patients with bipolar disorder. The effects of various light wavelengths on sleep in bipolar disorder require further investigation.

A double-blind, randomized, placebo-controlled trial of adjunctive blue-blocking glasses for the treatment of sleep and circadian rhythm in patients with bipolar disorder

OBJECTIVES

Recent studies have suggested that evening blue light exposure is associated with sleep and circadian rhythm abnormalities. This study examined the effect of blue-blocking (BB) glasses on sleep and circadian rhythm in patients with bipolar disorder (BD).

METHODS

We used a randomized, placebo-controlled, double-blinded design. Outpatients with BD and also with insomnia were randomly assigned to wear either orange glasses (BB) or clear ones (placebo) and were instructed to use these from 20:00 hours until bedtime for 2 weeks. The primary outcome metric was the difference in change from baseline to after intervention in sleep quality, as measured by the visual analog scale (VAS).

RESULTS

Forty-three patients were included in this study (BB group, 21; placebo group, 22). The change in sleep quality as per the VAS metric was not significantly different between the two groups (95% confidence interval [CI], -3.34 to 24.72; P = .13). However, the Morningness-Eveningness Questionnaire score had shifted to an advanced rhythm in the BB group and to a delayed rhythm in the placebo group, and the difference in these changes was statistically significant (95% CI, 1.69-7.45; P = .003). The change in the actigraphy sleep parameters and mood symptoms was not significantly different between the two groups.

CONCLUSION

Although concurrent medications may have influenced, our results suggest that BB glasses may be useful as an adjunctive treatment for circadian rhythm issues in patients with BD.

Visual and non-visual properties of filters manipulating short-wavelength light

Purpose

Optical filters and tints manipulating short‐wavelength light (sometimes called ‘blue‐blocking’ or ‘blue‐attenuating’ filters) are used in the management of a range of ocular, retinal, neurological and psychiatric disorders. In many cases, the only available quantification of the optical effects of a given optical filter is the spectral transmittance, which specifies the amount of light transmitted as a function of wavelength.

Methods

We propose a novel physiologically relevant and retinally referenced framework for quantifying the visual and non‐visual effects of these filters, incorporating the attenuation of luminance (luminous transmittance), the attenuation of melanopsin activation (melanopsin transmittance), the colour shift, and the reduction of the colour gamut (gamut reduction). Using these criteria, we examined a novel database of spectral transmittance functions of optical filters (n = 121) which were digitally extracted from a variety of sources.

Results

We find a large diversity in the alteration of visual and non‐visual properties. The spectral transmittance properties of the examined filters vary widely, in terms of shapes and cut‐off wavelengths. All filters show relatively more melanopsin attenuation than luminance attenuation (lower melanopsin transmittance than luminous transmittance). Across the data set, we find that melanopsin transmittance and luminous transmittance are correlated.

Conclusions

We suggest that future studies and examinations of the physiological effects of optical filters quantify the visual and non‐visual effects of the filters beyond the spectral transmittance, which will eventually aid in developing a mechanistic understanding of how different filters affect physiology. We strongly discourage comparing the downstream effects of different filters on, e.g. sleep or circadian responses, without considering their effects on the retinal stimulus.

The chronotherapeutic treatment of bipolar disorders: A systematic review and practice recommendations from the ISBD task force on chronotherapy and chronobiology

AIMS

To systematically review the literature on the efficacy and tolerability of the major chronotherapeutic treatments of bipolar disorders (BD)-bright light therapy (LT), dark therapy (DT), treatments utilizing sleep deprivation (SD), melatonergic agonists (MA), interpersonal social rhythm therapy (IPSRT), and cognitive behavioral therapy adapted for BD (CBTI-BP)-and propose treatment recommendations based on a synthesis of the evidence.

METHODS

PRISMA-based systematic review of the literature.

RESULTS

The acute antidepressant (AD) efficacy of LT was supported by several open-label studies, three randomized controlled trials (RCTs), and one pseudorandomized controlled trial. SD showed rapid, acute AD response rates of 43.9%, 59.3%, and 59.4% in eight case series, 11 uncontrolled, studies, and one RCT, respectively. Adjunctive DT obtained significant, rapid anti-manic results in one RCT and one controlled study. The seven studies on MA yielded very limited data on acute antidepressant activity, conflicting evidence of both antimanic and maintenance efficacy, and support from two case series of improved sleep in both acute and euthymic states. IPSRT monotherapy for bipolar II depression had acute response rates of 41%, 67%, and 67.4% in two open studies and one RCT, respectively; as adjunctive therapy for bipolar depression in one RCT, and efficacy in reducing relapse in two RCTs. Among euthymic BD subjects with insomnia, a single RCT found CBTI-BP effective in delaying manic relapse and improving sleep. Chronotherapies were generally safe and well-tolerated.

CONCLUSIONS

The outcome literature on the adjunctive use of chronotherapeutic treatments for BP is variable, with evidence bases that differ in size, study quality, level of evidence, and non-standardized treatment protocols. Evidence-informed practice recommendations are offered.

Light exposure at night and sleep quality in bipolar disorder: The APPLE cohort study

BACKGROUND

Sleep disturbance in bipolar disorder (BD) is common and is associated with a risk for mood episode recurrence. Thus, it is important to identify factors that are related to sleep disturbance in BD. This cross-sectional study investigated the association between exposure to light at night (LAN) and sleep parameters in patients with BD.

METHODS

The sleep parameters of 175 outpatients with BD were recorded using actigraphy at their homes for seven consecutive nights and were evaluated using the Insomnia Severity Index (ISI). The average LAN intensity in the bedroom during bedtime and rising time was measured using a portable photometer, and the participants were divided into two groups: "Light" (≥5 lx) and "Dark" (<5 lx). The association between LAN and sleep parameters was tested with multivariable analysis by adjusting for potential confounder such as age, gender, current smoker, mood state, day length, daytime light exposure, and sedative medications.

RESULTS

After adjusting for potential confounder, the actigraphy sleep parameters showed significantly lower sleep efficiency (mean, 80.1%vs. 83.4%; p = 0.01), longer log-transformed sleep onset latency (2.9 vs. 2.6 min; p = 0.01), and greater wake after sleep onset (51.4 vs. 41.6 min; p = 0.02) in the Light group than in the Dark group. Whereas, there were no significant differences in the ISI scores between the groups.

LIMITATIONS

This was a cross-sectional study; therefore, the results do not necessarily imply that LAN causes sleep disturbance.

CONCLUSIONS

Reducing LAN exposure may contribute to improved sleep quality in patients with BD.

Traits related to bipolar disorder are associated with an increased post-illumination pupil response

Mood states in bipolar disorder appear to be closely linked to changes in sleep and circadian function. It has been suggested that hypersensitivity of the circadian system to light may be a trait vulnerability for bipolar disorder. Healthy persons with emotional-behavioural traits associated with bipolar disorder also appear to exhibit problems with circadian rhythms, which may be associated with individual differences in light sensitivity. This study investigated the melanopsin-driven post-illumination pupil response (PIPR) in relation to emotional-behavioural traits associated with bipolar disorder (measured with the General Behavior Inventory) in a non-clinical group (n = 61). An increased PIPR was associated with increased bipolar disorder-related traits. Specifically, the hypomania scale of the General Behavior Inventory was associated with an increased post-blue PIPR. Further, both the full hypomania and shortened '7 Up' scales were significantly predicted by PIPR, after age, sex and depressive traits were controlled. These findings suggest that increased sensitivity to light may be a risk factor for mood problems in the general population, and support the idea that hypersensitivity to light is a trait vulnerability for, rather than symptom of, bipolar disorder.

Neuropsychological Function Response to Nocturnal Blue Light Blockage in Individuals With Symptoms of Insomnia: A Pilot Randomized Controlled Study

OBJECTIVES

Insomnia is associated with neuropsychological dysfunction. Evidence points to the role of nocturnal light exposure in disrupted sleep patterns, particularly blue light emitted through smartphones and computers used before bedtime. This study aimed to test whether blocking nocturnal blue light improves neuropsychological function in individuals with insomnia symptoms.

METHODS

This study used a randomized, placebo-controlled crossover design. Participants were randomly assigned to a 1-week intervention with amber lenses worn in wrap-around frames (to block blue light) or a 1-week intervention with clear lenses (control) and switched conditions after a 4-week washout period. Neuropsychological function was evaluated with tests from the NIH Toolbox Cognition Battery at three time points: (1) baseline (BL), (2) following the amber lenses intervention, and (3) following the clear lenses intervention. Within-subjects general linear models contrasted neuropsychological test performance following the amber lenses and clear lenses conditions with BL performance.

RESULTS

Fourteen participants (mean(standard deviation, SD): age = 46.5(11.4)) with symptoms of insomnia completed the protocol. Compared with BL, individuals performed better on the List Sorting Working Memory task after the amber lenses intervention, but similarly after the clear lenses intervention (F = 5.16; p = .014; η2 = 0.301). A similar pattern emerged on the Pattern Comparison Processing Speed test (F = 7.65; p = 0.002; η2 = 0.370). Consideration of intellectual ability indicated that treatment with amber lenses "normalized" performance on each test from approximately 1 SD below expected performance to expected performance.

CONCLUSIONS

Using a randomized, placebo-controlled crossover design, we demonstrated improvement in processing speed and working memory with a nocturnal blue light blocking intervention among individuals with insomnia symptoms. (JINS, 2019, 25, 668-677).

A pragmatic effectiveness randomized controlled trial of the duration of psychiatric hospitalization in a trans-diagnostic sample of patients with acute mental illness admitted to a ward with either blue-depleted evening lighting or normal lighting conditions

Background

There is increasing recognition of the need to stabilize sleep-wake cycles in individuals with major mental disorders. As such, clinicians and researchers advocate the use of interventions targeted at sleep and circadian dysrhythmias as an adjunct to the standard treatments offered for acute illness episodes of a broad range of diagnoses. To determine the trans-diagnostic generalizability of chronotherapy, we explore the benefits of admitting individuals with an acute illness episode to a psychiatric inpatient unit where changes in light exposure are integrated into the therapeutic environment.

Methods/design

A two-arm, pragmatic effectiveness, randomized controlled treatment trial, where individuals admitted for acute inpatient psychiatric care will be allocated to a ward with blue-depleted evening light or to a ward with the same layout and facilities but lacking the new lighting technology. The trial will test whether the experimental lighting conditions offer any additional benefits beyond those associated with usual treatment in an acute psychiatric inpatient unit. The main objectives are to examine any differences between groups in the mean duration of hospitalization in days. Additional analyses will compare group differences in symptoms, functioning, medication usage, and side effects and whether length of stay is associated with stability of sleep-wake cycles and circadian rhythms. Ancillary investigations should determine any benefits according to diagnostic subgroups and potential drawbacks such as any adverse effects on the well-being of professionals working across both wards.

Discussion

This unit offers a unique opportunity to explore how exposure to different lighting conditions may modify sleep-wake cycles and how any changes in sleep-wake cycle may impact on the clinical and functional outcomes of individuals experiencing an acute episode of a severe mental disorder that requires inpatient care. The findings could influence the future design of hospital units offering care to patients with mental or physical disorders.

Trial registration

ClinicalTrials.gov, ID: NCT03788993. Retrospectively registered on 28 December 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3582-2) contains supplementary material, which is available to authorized users.

Treating Circadian Rhythm Disruption in Bipolar Disorder

PURPOSE OF REVIEW

Disruptions in circadian rhythms are believed to underlie the illness course of bipolar disorder (BD). This review evaluates recent studies on the treatment of circadian dysfunction in BD.

RECENT FINDINGS

Targeted social rhythm therapy may be useful for bipolar depression though some studies suggest that a non-targeted psychosocial or pharmacological intervention may be just as efficacious. Lithium holds potential for addressing circadian dysfunction in BD. Blue-blocking therapy may be useful for mania and midday bright light therapy may relieve depression.

CONCLUSIONS

Psychosocial, pharmacological, and light-based approaches are promising avenues for treating circadian dysfunction in BD.

Blue blocking glasses worn at night in first year higher education students with sleep complaints: a feasibility study

Background

Late adolescence and early adulthood is a period of highest incidence for onset of mental health problems. Transition to college environment has been associated with many risk factors such as the initial disruption—and subsequent irregularity—of the student’s sleep and activity schedule. We tested the feasibility of using blue blocking glasses (BBG) at night in first year higher education students with sleep complaints, to obtain preliminary evidence for the impact of BBG on sleep, activity, and mood.

Methods

Participants were 13 first year undergraduates (from 10 different academic courses) living on campus for the first time with sleep complaints/disorders confirmed at screening via the Duke Structured Interview Schedule for Sleep Disorders. We used a 2-week, balanced crossover design (BBG vs placebo glasses; participants were unaware which was the active intervention) with computer-generated random allocation. Exploratory analyses provided descriptive and frequency summaries to evaluate feasibility of the intervention.

Results

Preliminary evidence supports the feasibility and acceptability of the trial; almost all screened participants consented and completed the protocol with high adherence; missing data were negligible. Additionally, the effectiveness of BBGs to enhance sleep, mood, and activity levels in young adults was supported.

Conclusions

The results of this feasibility trial suggest that BBG have potential as an inexpensive and feasible intervention for reducing sleep and circadian dysregulation in young adult students. A larger trial, following this successfully implemented protocol, is necessary to fully test the efficacy of BBG.

Visceral theory of sleep and origins of mental disorders

Visceral theory of sleep states that the same brain neurons, which process external information in wakefulness, during sleep switch to the processing of internal information coming from various visceral systems. Here we hypothesize that a failure in the commutation of exteroceptive and interoceptive information flows in the brain can manifest itself as a mental illness.

Blocking nocturnal blue light for insomnia: A randomized controlled trial

The use of light-emitting electronic devices before bedtime may contribute to or exacerbate sleep problems. Exposure to blue-wavelength light in particular from these devices may affect sleep by suppressing melatonin and causing neurophysiologic arousal. We aimed to determine if wearing amber-tinted blue light-blocking lenses before bedtime improves sleep in individuals with insomnia. Fourteen individuals (n = 8 females; age ± SD 46.6 ± 11.5 y) with insomnia symptoms wore blue light-blocking amber lenses or clear placebo lenses in lightweight wraparound frames for 2 h immediately preceding bedtime for 7 consecutive nights in a randomized crossover trial (4-wk washout). Ambulatory sleep measures included the Pittsburgh Insomnia Rating Scale (PIRS) completed at the end of each intervention period, and daily post-sleep questionnaire and wrist-actigraphy. PIRS total scores, and Quality of Life, Distress, and Sleep Parameter subscales, were improved in amber vs. clear lenses condition (p-values <0.05). Reported wake-time was significantly delayed, and mean subjective total sleep time (TST), overall quality, and soundness of sleep were significantly higher (p-values <0.05) in amber vs. clear lenses condition over the 7-d intervention period. Actigraphic measures of TST only were significantly higher in amber vs. clear lenses condition (p = 0.035). Wearing amber vs. clear lenses for 2-h preceding bedtime for 1 week improved sleep in individuals with insomnia symptoms. These findings have health relevance given the broad use of light-emitting devices before bedtime and prevalence of insomnia. Amber lenses represent a safe, affordable, and easily implemented therapeutic intervention for insomnia symptoms.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov Identifier: NCT02698800.

Light therapy in the treatment of patients with bipolar depression: A meta-analytic study

Light therapy (LT) has been widely used in the treatment of seasonal affective disorder. Recently some evidence indicated that LT may play a role in bipolar depression, either as monotherapy or in combination with total sleep deprivation (TSD). However, the studies examining the treatment effect of LT in bipolar depression resulted in inconsistent findings. To clarify the role of LT in the disorder, we conducted a meta-analysis to compare the efficacy of LT in the treatment of bipolar depression. The results of individual studies were synthesized by a random effects model. Nine studies including 489 patients with bipolar depression were included in this current meta-analysis. We found that disease severity was significantly decreased after LT, in both with and without TSD, and with concomitant medication (p<0.001). Augmentation treatment with LT significantly decreased disease severity compared to treatment without LT (p=0.024). Our results highlight the significant efficacy of LT, either as monotherapy or in combination with TSD, in the treatment of bipolar depression. However, the detailed mechanism of LT still remains elusive. Further well-designed controlled trials are required to investigate the optimal intensity and frequency of LT in the treatment of bipolar depression.

Blue-blocking glasses as additive treatment for mania: a randomized placebo-controlled trial

OBJECTIVES

The discovery of the blue lightsensitive retinal photoreceptor responsible for signaling daytime to the brain suggested that light to the circadian system could be inhibited by using blue-blocking orange tinted glasses. Blue-blocking (BB) glasses are a potential treatment option for bipolar mania. We examined the effectiveness of BB glasses in hospitalized patients with bipolar disorder in a manic state.

METHODS

In a single-blinded, randomized, placebo-controlled trial (RCT), eligible patients (with bipolar mania; age 18-70 years) were recruited from five clinics in Norway. Patients were assigned to BB glasses or placebo (clear glasses) from 6 p.m. to 8 a.m. for 7 days, in addition to treatment as usual. Symptoms were assessed daily by use of the Young Mania Rating Scale (YMRS). Motor activity was assessed by actigraphy, and compared to data from a healthy control group. Wearing glasses for one evening/night qualified for inclusion in the intention-to-treat analysis.

RESULTS

From February 2012 to February 2015, 32 patients were enrolled. Eight patients dropped out and one was excluded, resulting in 12 patients in the BB group and 11 patients in the placebo group. The mean decline in YMRS score was 14.1 [95% confidence interval (CI): 9.7-18.5] in the BB group, and 1.7 (95% CI: -4.0 to 7.4) in the placebo group, yielding an effect size of 1.86 (Cohen's d). In the BB group, one patient reported headache and two patients experienced easily reversible depressive symptoms.

CONCLUSIONS

This RCT shows that BB glasses are effective and feasible as add-on treatment for bipolar mania.

The bipolarity of light and dark: A review on Bipolar Disorder and circadian cycles

BACKGROUND

Bipolar Disorder is characterized by episodes running the full mood spectrum, from mania to depression. Between mood episodes, residual symptoms remain, as sleep alterations, circadian cycle disturbances, emotional deregulation, cognitive impairment and increased risk for comorbidities. The present review intends to reflect about the most recent and relevant information concerning the biunivocal relation between bipolar disorder and circadian cycles.

METHODS

It was conducted a literature search on PubMed database using the search terms "bipolar", "circadian", "melatonin", "cortisol", "body temperature", "Clock gene", "Bmal1 gene", "Per gene", "Cry gene", "GSK3β", "chronotype", "light therapy", "dark therapy", "sleep deprivation", "lithum" and "agomelatine". Search results were manually reviewed, and pertinent studies were selected for inclusion as appropriate.

RESULTS

Several studies support the relationship between bipolar disorder and circadian cycles, discussing alterations in melatonin, body temperature and cortisol rhythms; disruption of sleep/wake cycle; variations of clock genes; and chronotype. Some therapeutics for bipolar disorder directed to the circadian cycles disturbances are also discussed, including lithium carbonate, agomelatine, light therapy, dark therapy, sleep deprivation and interpersonal and social rhythm therapy.

LIMITATIONS

This review provides a summary of an extensive research for the relevant literature on this theme, not a patient-wise meta-analysis.

CONCLUSIONS

In the future, it is essential to achieve a better understanding of the relation between bipolar disorder and the circadian system. It is required to establish new treatment protocols, combining psychotherapy, therapies targeting the circadian rhythms and the latest drugs, in order to reduce the risk of relapse and improve affective behaviour.

Sleep- and circadian rhythm-associated pathways as therapeutic targets in bipolar disorder

INTRODUCTION

Disruptions in sleep and circadian rhythms are observed in individuals with bipolar disorders (BD), both during acute mood episodes and remission. Such abnormalities may relate to dysfunction of the molecular circadian clock and could offer a target for new drugs.

AREAS COVERED

This review focuses on clinical, actigraphic, biochemical and genetic biomarkers of BDs, as well as animal and cellular models, and highlights that sleep and circadian rhythm disturbances are closely linked to the susceptibility to BDs and vulnerability to mood relapses. As lithium is likely to act as a synchronizer and stabilizer of circadian rhythms, we will review pharmacogenetic studies testing circadian gene polymorphisms and prophylactic response to lithium. Interventions such as sleep deprivation, light therapy and psychological therapies may also target sleep and circadian disruptions in BDs efficiently for treatment and prevention of bipolar depression.

EXPERT OPINION

We suggest that future research should clarify the associations between sleep and circadian rhythm disturbances and alterations of the molecular clock in order to identify critical targets within the circadian pathway. The investigation of such targets using human cellular models or animal models combined with 'omics' approaches are crucial steps for new drug development.

Blocking blue light during mania - markedly increased regularity of sleep and rapid improvement of symptoms: a case report

OBJECTIVE

Available pharmacological treatment of mania is insufficient. Virtual darkness therapy (blue light-blocking treatment by means of orange-tinted glasses) is a promising new treatment option for mania. The basis for this might be the recently identified blue light-sensitive retinal photoreceptor, which is solely responsible for light stimulus to the circadian master clock. This is the first case report describing the clinical course of a closely monitored, hospitalized patient in a manic episode first receiving clear-lensed, and then blue light-blocking glasses.

METHODS

A 58-year-old Caucasian man, with bipolar I disorder and three previous manic episodes, was hospitalized during a manic episode. In addition to pharmacological treatment, he was treated with clear-lensed glasses for seven days, then one day without glasses, followed by six days of blue light-blocking glasses. During the entire observational period, he wore an actigraph with internal light sensors.

RESULTS

Manic symptoms were unaltered during the first seven days. The transition to the blue-blocking regime was followed by a rapid and sustained decline in manic symptoms accompanied by a reduction in total sleep, a reduction in motor activity during sleep intervals, and markedly increased regularity of sleep intervals. The patient's total length of hospital stay was 20 days shorter than the average time during his previous manic episodes.

CONCLUSIONS

The unusually rapid decline in symptoms, accompanied by uniform sleep parameter changes toward markedly increased regularity, suggest that blue-blockers might be targeting a central mechanism in the pathophysiology of mania that needs to be explored both in clinical research and in basic science.

Circadian rhythms and sleep in bipolar disorder: implications for pathophysiology and treatment

PURPOSE OF REVIEW

Multiple lines of evidence support the conceptualization of bipolar disorder as a disorder of circadian rhythms. Considering bipolar disorder in the framework of circadian disturbances also helps understand the clinical phenomenology pointing toward a multisystemic involvement.

RECENT FINDINGS

Patients with bipolar disorder show altered rhythmicity in body temperature and melatonin rhythms, high day-to-day variability in activity and sleep timing, persistent disturbances of sleep or wake cycles, including disturbances of sleep continuity. The internal clocks are, indeed, responsible for regulating a variety of physiologic functions, including appetitive behaviors, cognitive functions and metabolism.

SUMMARY

An underlying circadian pathology in bipolar disorder is a unifying explicatory model for the high psychiatric and medical comorbidity observed during the long-term course of the disorder. This model also provides a rationale for therapeutic interventions aimed at re-entraining the internal clock.

Inpatient treatment for mania: A review and rationale for adjunctive interventions

OBJECTIVE

To examine the evidence for adjunctive non-pharmacological interventions in the treatment of mania in an acute inpatient setting.

METHOD

A selective review of original and review papers was conducted. The electronic databases PsycINFO and PubMed were searched using the following MeSH terms: mania, mania treatment and inpatient.

RESULTS

Four studies were identified in the search for non-psychopharmacological interventions for mania that commenced in an inpatient setting: Interpersonal and Social Rhythm Therapy (IPSRT), Group Cognitive Behavioural Therapy (G-CBT), sensory room, and dark room therapy. Only two of these were designed exclusively for patients with bipolar disorder and the other two included these patients in a heterogeneous group of acute psychiatric inpatients.

CONCLUSIONS

Sleep and circadian regulation (Social Rhythm Therapy) that focuses on the establishment and maintenance of regular daily rhythms, particularly in relation to sleep-wake times, meal times and socialization, provides a potentially useful model for managing mania in the inpatient setting. However, there is an urgent need for further research into the effective treatment of mania.

Basic sleep and circadian science as building blocks for behavioral interventions: a translational approach for mood disorders

Sleep and circadian functioning has been of particular interest to researchers focused on improving treatments for psychiatric illness. The goal of the present paper is to highlight the exciting research that utilizes basic sleep and circadian science as building blocks for intervention in the mood disorders. The reviewed evidence suggests that the sleep and circadian systems are a) disrupted in the mood disorders and linked to symptoms, b) open systems that can be modified, c) the focus of interventions which have been developed to effectively treat sleep disturbance within mood disorders, and d) intimately linked with mood, such that improvements in sleep are associated with improvements in mood. Although significant positive treatment effects are evident, more research is needed to fill the gap in our basic understanding of the relationship between sleep and mood.

Cyclin-dependent kinase 5 (Cdk5) regulates the function of CLOCK protein by direct phosphorylation

Circadian rhythm is a biological rhythm governing physiology and behavior with a period of ∼24 h. At the molecular level, circadian output is controlled by a molecular clock composed of positive and negative feedback loops in transcriptional and post-translational processes. CLOCK is a transcription factor known as a central component of the molecular clock feedback loops generating circadian oscillation. Although CLOCK is known to undergo multiple post-translational modifications, the knowledge of their entities remains limited. Cyclin-dependent kinase 5 (Cdk5) is a proline-directed serine-threonine kinase that is involved in various neuronal processes. Here, we report that Cdk5 is a novel regulator of CLOCK protein. Cdk5 phosphorylates CLOCK at the Thr-451 and Thr-461 residues in association with transcriptional activation of CLOCK. The Cdk5-dependent regulation of CLOCK function is mediated by alterations of its stability and subcellular distribution. These results suggest that Cdk5 is a novel regulatory component of the core molecular clock machinery.

Chronobiology of mood disorders

OBJECTIVE

As part of a series of papers examining chronobiology ['Getting depression clinical guidelines right: time for change?' Kuiper et al. Acta Psychiatr Scand 2013;128(Suppl. 444):24-30; and 'Manipulating melatonin in managing mood' Boyce & Hopwood. ActaPsychiatrScand 2013;128(Suppl. 444):16-23], in this article, we review and synthesise the extant literature pertaining to the chronobiology of depression and provide a preliminary model for understanding the neural systems involved.

METHOD

A selective literature search was conducted using search engines such as MEDLINE/PubMed, combining terms associated with chronobiology and mood disorders.

RESULTS

We propose that understanding of sleep-wake function and mood can be enhanced by simultaneously considering the circadian system, the sleep homoeostat and the core stress system, all of which are likely to be simultaneously disrupted in major mood disorders. This integrative approach is likely to allow flexible modelling of a much broader range of mood disorder presentations and phenomenology.

CONCLUSION

A preliminary multifaceted model is presented, which will require further development and testing. Future depression research should aim to examine multiple systems concurrently in order to derive a more sophisticated understanding of the underlying neurobiology.

Day type and the relationship between weight status and sleep duration in children and adolescents

OBJECTIVE

This study aimed to explore sleep duration in young Australians on different types of days across weight classes.

METHODS

Use of time and anthropometric data were collected on 8,866 nights from 3,884 9-18 year old Australians. The association between sleep duration and weight status was examined using factorial ANOVA for four day types: S-S (to bed and waking on school days); S-NS (to bed on school day and waking on non-school day); NS-NS (to bed and waking on non-school days); NS-S (to bed on non-school day and waking on school day).

RESULTS

Sleep duration varied with weight status when all day types were considered together (p=0.0012). Obese adolescents slept less than normal and underweight adolescents. However, the relationship varied for different day types; with the strongest relationship for NS-S days (on which obese children slept 65 min less than very underweight children, p<0.0001).

CONCLUSIONS

The association between weight status and sleep duration showed consistent gradients across weight categories, but only for certain day types.

IMPLICATIONS

These patterns cast light on the direction of causation in the obesity-sleep duration relationship. Findings suggest that short sleep duration contributes to obesity, or that a third unidentified factor has an impact on both.

Evolutionary origin of bipolar disorder-revised: EOBD-R

The hypothesis of the evolutionary origin of bipolar disorder (EOBD) synthesized ideas about the biological clock and seasonal shifts in mood (Rosenthal, Wehr) with theorizing that bipolar disorder descends from a pyknic (compact, cold-adapted) group (Kretchmer). The hypothesis suggested that bipolar behaviors evolved in the northern temperate zone as highly derived adaptations to the selective pressures of severe climatic conditions during the Pleistocene. Given evidence of Neandertal contributions to the human genome, the hypothesis is extended (EOBD-R) to suggest Neandertal as the ancestral source for bipolar vulnerability genes (susceptibility alleles). The EOBD-R hypothesis explains and integrates existing observations: bipolar disorder has the epidemiology of an adaptation; it is correlated with a cold-adapted build, and its moods vary according to light and season. Since the hypothesis was first published, data consistent with it have continued to appear. Individuals with seasonal affective disorder, which is related to bipolar disorder, have been shown to manifest a biological signal of season change similar to that found in hibernating animals. The involvement of the circadian gene network in the pathophysiology of bipolar disorder has been confirmed. Because selective pressures during the Pleistocene would have been greatest for women of reproductive age, they are expected to manifest winter depression more than males or younger females, which is the case. (This sex difference is also found in hibernating mammals.) Because it is hypothesized that the evolution of bipolar disorder took place in the northern temperate zone during the Pleistocene, it is not expected that individuals of African descent, lacking Neandertal genes, will manifest circular bipolar I disorder, and in fact, the incidence of bipolar disorder among black individuals is less than among whites. A definitive test of the hypothesis is proposed: It is predicted that the bipolar and Neandertal genomes will be more similar than the modern human and Neandertal genomes, and the modern human and San and Yoruba genomes will be more similar than the bipolar and San and Yoruba genomes. Failure to confirm these predictions will falsify the EOBD-R hypothesis. The EOBD-R hypothesis has important implications in the search for bipolar vulnerability genes and our understanding of ourselves and our Neandertal ancestor. At a practical level, confirmation of the EOBD-R hypothesis will boost interest and research in the prevention and management of bipolar symptoms by manipulation of ambient light.

Sleep disturbance as transdiagnostic: consideration of neurobiological mechanisms

Sleep disturbance is increasingly recognized as an important, but understudied, mechanism in the complex and multi-factorial causation of the symptoms and functional disability associated with psychiatric disorders. This review proposes that it is biologically plausible for sleep disturbance to be mechanistically transdiagnostic. More specifically, we propose that sleep disturbance is aetiologically linked to various forms of psychopathology through: its reciprocal relationship with emotion regulation and its shared/interacting neurobiological substrates in (a) genetics--genes known to be important in the generation and regulation of circadian rhythms have been linked to a range of disorders and (b) dopaminergic and serotonergic function--we review evidence for the interplay between these systems and sleep/circadian biology. The clinical implications include potentially powerful and inexpensive interventions including interventions targeting light exposure, dark exposure, the regulation of social rhythms and the reduction of anxiety. We also consider the possibility of developing a 'transdiagnostic' treatment; one treatment that would reduce sleep disturbance across psychiatric disorders.

Amber lenses to block blue light and improve sleep: a randomized trial

All light is not equal: blue wavelengths are the most potent portion of the visible electromagnetic spectrum for circadian regulation. Therefore, blocking blue light could create a form of physiologic darkness. Because the timing and quantity of light and darkness both affect sleep, evening use of amber lenses to block blue light might affect sleep quality. Mood is also affected by light and sleep; therefore, mood might be affected by blue light blockade. In this study, 20 adult volunteers were randomized to wear either blue-blocking (amber) or yellow-tinted (blocking ultraviolet only) safety glasses for 3 h prior to sleep. Participants completed sleep diaries during a one-week baseline assessment and two weeks' use of glasses. Outcome measures were subjective: change in overall sleep quality and positive/negative affect. Results demonstrated that sleep quality at study outset was poorer in the amber lens than the control group. Two- by three-way ANOVA revealed significant (p < .001) interaction between quality of sleep over the three weeks and experimental condition. At the end of the study, the amber lens group experienced significant (p < .001) improvement in sleep quality relative to the control group and positive affect (p = .005). Mood also improved significantly relative to controls. A replication with more detailed data on the subjects' circadian baseline and objective outcome measures is warranted.

Serotonergic potentiation of dark pulse-induced phase-shifting effects at midday in hamsters

In mammals, resetting of the suprachiasmatic clock (SCN) by behavioral activation or serotonin (5-HT) agonists is mimicked by dark pulses, presented during subjective day in constant light (LL). Because behavioral resetting may be mediated in part by 5-HT inputs to the SCN, here we determined whether 5-HT system can modulate dark-induced phase-shifts in Syrian hamsters housed in LL. Two hours of darkness at mid-subjective day (circadian time 6; CT-6) resulted in increased concentrations of 5-HT in the SCN tissue and induction of c-FOS expression in the raphe nuclei. Injections of the 5-HT(1A/7) agonist +8-OH-DPAT or dark pulses at CT-6 induced phase-advances of the wheel-running activity rhythm and down-regulated the expression of the clock genes Per1-2 and c-FOS in the SCN in a similar way. The combination of both treatments [+8-OH-DPAT + dark pulses], however, resulted in larger phase-advances, while associated molecular changes were not significantly modified, except for the gene Dbp, in comparison to +8-OH-DPAT or dark pulses alone. Dark resetting was blocked by pre-treatment with a 5-HT(7) antagonist, but not with a 5-HT(1A) antagonist. The additive phase-shifts of two different cues to reset the SCN clock open wide the gateway for non-photic shifting, leading to new strategies in chronotherapy.