The potential influence of LED lighting on mental illness

Artificial Light at Night and Type 2 Diabetes Mellitus

The widespread and pervasive use of artificial light at night (ALAN) in our modern 24-hour society has emerged as a substantial disruptor of natural circadian rhythms, potentially leading to a rise in unhealthy lifestyle-related behaviors (e.g., poor sleep; shift work). This phenomenon has been associated with an increased risk of type 2 diabetes mellitus (T2DM), which is a pressing global public health concern. However, to date, reviews summarizing associations between ALAN and T2DM have primarily focused on the limited characteristics of exposure (e.g., intensity) to ALAN. This literature review extends beyond prior reviews by consolidating recent studies from 2000 to 2024 regarding associations between both indoor and outdoor ALAN exposure and the incidence or prevalence of T2DM. We also described potential biological mechanisms through which ALAN modulates glucose metabolism. Furthermore, we outlined knowledge gaps and investigated how various ALAN characteristics beyond only light intensity (including light type, timing, duration, wavelength, and individual sensitivity) influence T2DM risk. Recognizing the detrimental impact of ALAN on sleep health and the behavioral correlates of physical activity and dietary patterns, we additionally summarized studies investigating the potential mediating role of each component in the relationship between ALAN and glucose metabolism. Lastly, we proposed implications of chronotherapies and chrononutrition for diabetes management in the context of ALAN exposure.

New Series of Red-Light Phosphor Ca9-xZnxGd0.9(PO4)7:0.1Eu3+ (x = 0-1)

In this study, a new series of phosphors, Ca9−xZnxGd0.9(PO4)7:0.1Eu3+ (x = 0.00−1.00, step dx 0.05), was synthesized, consisting of centro- and non-centrosymmetric phases with β-Ca3(PO4)2-type structure. Crystal structures with space groups R3c (0.00 ≤ x < 0.35) and R3¯c (x > 0.8) were determined using X-ray powder diffraction and the method of optical second harmonic generation. In the region 0.35 ≤ x ≤ 0.75, phases R3c and R3¯c were present simultaneously. Refinement of the Ca8ZnGd(PO4)7 crystal structure with the Rietveld method showed that 71% of Gd3+ ions are in M3 sites and 29% are in M1 sites. A luminescent spectroscopy study of Ca9−xZnxGd0.9(PO4)7:0.1Eu3+ indicated the energy transfer from the crystalline host to the Gd3+ and Eu3+ luminescent centers. The maximum Eu3+ luminescence intensity corresponds to the composition with x = 1.

Association between polarity of first episode and solar insolation in bipolar I disorder

OBJECTIVE

Circadian rhythm disruption is commonly observed in bipolar disorder (BD). Daylight is the most powerful signal to entrain the human circadian clock system. This exploratory study investigated if solar insolation at the onset location was associated with the polarity of the first episode of BD I. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area of the Earth.

METHODS

Data from 7488 patients with BD I were collected at 75 sites in 42 countries. The first episode occurred at 591 onset locations in 67 countries at a wide range of latitudes in both hemispheres. Solar insolation values were obtained for every onset location, and the ratio of the minimum mean monthly insolation to the maximum mean monthly insolation was calculated. This ratio is largest near the equator (with little change in solar insolation over the year), and smallest near the poles (where winter insolation is very small compared to summer insolation). This ratio also applies to tropical locations which may have a cloudy wet and clear dry season, rather than winter and summer.

RESULTS

The larger the change in solar insolation throughout the year (smaller the ratio between the minimum monthly and maximum monthly values), the greater the likelihood the first episode polarity was depression. Other associated variables were being female and increasing percentage of gross domestic product spent on country health expenditures. (All coefficients: P ≤ 0.001).

CONCLUSION

Increased awareness and research into circadian dysfunction throughout the course of BD is warranted.

Influence of Visible Violet, Blue and Red Light on the Development of Cataract in Porcine Lenses

Background and Objectives: Cataract is a disease that is globally prevalent in today’s population and occurs mostly in the elderly. It is an opacity of the lens that worsens vision and can lead to blindness. One well-known risk factor of cataract is ultraviolet (UV) radiation. However, increasing exposure to modern artificial light sources like light emitting diodes (LEDs) and displays might have an impact on cataract formation due to possible high (and hidden) blue radiation. An ex-vivo study indicates that intense blue radiation causes cataract in porcine lenses. The goal of this work is the investigation whether violet or red light also lead to cataract formation in porcine lenses and to compare the impact of the different wavelengths. Materials and Methods: LEDs with wavelengths of 407 nm (violet), 463 nm (blue) and 635 nm (red) are used to irradiate ex–vivo porcine lenses with a dose of 6 kJ/cm². Before and after irradiation the lens transmissions are measured and dark field images are taken to determine cataract formation. The same procedure is performed for unirradiated controls. Results: The results of the transmission measurements are in accordance with the results of the dark field images and state that 635 nm (red) is inducing no or only weak cataract. In comparison to the dark field images the transmission measurements exhibit stronger cataract formation for 407 nm than for 463 nm irradiation while the dark field images show similar cataract formation for both wavelengths. Conclusions: Visible light of short wavelengths cause cataract formation in porcine eyes, and it cannot be excluded that these wavelengths, which are emitted by modern LED illuminants, also pose a danger to human eyes.

Selective blue-filtering spectacle lens protected primary porcine RPE cells against light emitting diode-induced cell damage

This study aimed to investigate whether use of a selective-blue-filtering (S-BF) lens can protect cultured primary porcine RPE cells against photo-irradiation. Transmittance of S-BF and UV-filtering (UVF) lenses was characterised spectrophotometrically. RPE cells were exposed to 1700 lux of white (peak λ at 443 and 533 nm; 0.44 mW/cm²) or blue (peak λ at 448 and 523 nm; 0.85 mW/cm²) LED light for 16 h to evaluate the influence of light source on the culture. The effect of the S-BF and UVF ophthalmic lenses on RPE cell cultures under blue light irradiation was then investigated. Cell viability was compared using trypan blue and MTT assays. Intracellular ROS production was detected by a fluorescein probe CM-H2DCFDA. Expression levels of catalase and Prdx3 were analysed by western blot. Trypan blue staining showed blue light caused more cell death than no light (p = 0.001) or white light (p = 0.005). MTT assay supported the hypothesis that exposure to blue light damaged RPE cells more severely than no light (p = 0.002) or white light (p = 0.014). Under blue light, use of the S-BF lens, which blocked 17% more blue light than the UVF lens, resulted in higher cellular viability (S-BF: 93.4±1.4% vs UVF: 90.6±1.4%; p = 0.022; MTT: 1.2-fold; p = 0.029). Blue and white light both significantly increased ROS production. The S-BF lens protected cells, resulting in lower levels of ROS and higher expression of catalase and Prdx3. To conclude, blue LED light exposure resulted in significant cytotoxicity to RPE cells. Partial blockage of blue light by an S-BF lens led to protective effects against retinal phototoxicity, which were mediated by reduction of ROS and increased levels of antioxidant enzymes.

Daytime Exposure to Blue Light Alters Cardiovascular Circadian Rhythms, Electrolyte Excretion and Melatonin Production

Artificial light is characterized by certain features of its impact on the body in terms of its spectral distribution of power, duration of exposure and intensity. Short waves, perceived as blue light, are the strongest synchronizing agent for the circadian system. In the present work, we investigated the features of the circadian rhythms of blood pressure (BP), heart rate (HR), the excretion of electrolytes and the secretion of melatonin in normotensive (Wistar–Kyoto) and hypertensive (SHR) rats under the action of monochromatic blue light in the daytime period. It was found that the exposure of Wistar–Kyoto rats to monochromatic blue light was accompanied by a significant decrease in nighttime and 24 h systolic BP. The most remarkable changes are characteristic of the HR in SHR rats under monochromatic light. A significant decrease in HR in each time period was found, but the predominance of nighttime over daytime values remained in SHR animals. There was also a significant increase in the mesor of the HR in SHR rats. Additionally, the amplitude of diastolic BP and HR, as well as the range of oscillations in HR, were significantly increased compared with the standard light pattern. In contrast to SHR rats, the regulation of the circadian rhythms in Wistar–Kyoto rats was more flexible and presented more changes, which may be aimed at the adaptation of the body to environmental conditions. For Wistar–Kyoto rats, an increase in the level of excreted electrolytes was observed under the action of monochromatic light, but no similar changes were found in SHR rats. For Wistar–Kyoto rats, a significant decrease in the urine concentration of aMT6s in the daytime and nighttime periods is characteristic, which results in the loss of the circadian rhythm. In SHR rats, there was a significant decrease in the nighttime content of aMT6s in the urine, while the daytime concentration, on the contrary, increased. The obtained data demonstrate that prolonged exposure to monochromatic blue light in the daytime period affects the circadian structure of the rhythms of the cardiovascular system, the rhythm of electrolyte excretion and the production of epiphyseal melatonin in wild-type and hypertensive animals. In SHR rats, the rhythms of BP and HR exhibit a more rigid pattern.

Influence of External Natural Environment Including Sunshine Exposure on Public Mental Health: A Systematic Review

The COVID-19 pandemic has been raging around the world and public health measures such as lockdowns have forced people to go out less often, reducing sunlight exposure time, green space use, and physical activity. It is well known that exercise has a positive impact on mental health, but the impact of external environmental factors such as sunlight exposure and green space use on mental health has not been systematically reviewed. In this review, we categorized the major factors that may affect people’s mental health into (1) external environmental factors such as exposure to sunlight and green spaces, (2) internal life factors such as physical activity and lifestyle, and (3) mixed external and internal factors, and systematically examined the relationship between each factor and people’s mental health. The results showed that exposure to sunlight, spending leisure time in green spaces, and physical activity each had a positive impact on people’s mental health, including depression, anxiety, and stress states. Specifically, moderate physical activity in an external environment with sunlight exposure or green space was found to be an important factor. The study found that exposure to the natural environment through sunbathing and exercise is important for people’s mental health.

Blue Light-Induced Retinal Neuronal Injury and Amelioration by Commercially Available Blue Light-Blocking Lenses

Blue light exposure-induced retinal damage has been extensively studied. Although many in vitro studies have shown the benefits of blue light-blocking lenses (BBL) there have been few comprehensive in vivo studies to assess the effects of BBL. We investigated the influence of blue light exposure using light-emitting diodes on retinal histology and visual cortex neurons in rodents. We also considered whether retinal and cortical changes induced by blue light could be ameliorated with blue light-blocking lenses. A total of n = 24 (n = 6 in each group; control, light exposure without lenses, two different BBLs)) male Wistar rats were subjected to blue light exposure (LEDs, 450–500 lux) without or with BBLs (400–490 nm) for 28 days on a 12:12 h light–dark cycle. Histological analysis of retinae revealed apoptosis and necrosis of the retinal pigment epithelium (RPE), photoreceptors, and inner retina in the light exposure (LE) group, along with increase caspase-3 immunostaining in the ganglion cell layer (p < 0.001). BBL groups showed less caspase-3 immunostaining compared with the LE group (p < 0.001). V1-L5PNs (primary visual cortex layer 5 pyramidal neurons) demonstrated reduced branching and intersections points for apical (p < 0.001) and basal (p < 0.05) dendrites following blue light exposure. Blue light-blocking lenses significantly improved the number of basal branching points compared with the LE group. Our study shows that prolonged exposure to high levels of blue light pose a significant hazard to the visual system resulting in damage to the retina with the associated remodeling of visual cortex neurons. BBL may offer moderate protection against exposure to high levels of blue light.

Current Insights into Optimal Lighting for Promoting Sleep and Circadian Health: Brighter Days and the Importance of Sunlight in the Built Environment

This perspective considers the possibility that daytime's intrusion into night made possible by electric lighting may not be as pernicious to sleep and circadian health as the encroachment of nighttime into day wrought by 20th century architectural practices that have left many people estranged from sunlight.

Cataract Development by Exposure to Ultraviolet and Blue Visible Light in Porcine Lenses

Background and Objectives: Cataract is still the leading cause of blindness. Its development is well researched for UV radiation. Modern light sources like LEDs and displays tend to emit blue light. The effect of blue light on the retina is called blue light hazard and is studied extensively. However, its impact on the lens is not investigated so far. Aim: Investigation of the impact of the blue visible light in porcine lens compared to UVA and UVB radiation. Materials and Methods: In this ex-vivo experiment, porcine lenses are irradiated with a dosage of 6 kJ/cm2 at wavelengths of 311 nm (UVB), 370 nm (UVA), and 460 nm (blue light). Lens transmission measurements before and after irradiation give insight into the impact of the radiation. Furthermore, dark field images are taken from every lens before and after irradiation. Cataract development is illustrated by histogram linearization as well as faults coloring of recorded dark field images. By segmenting the lens in the background's original image, the lens condition before and after irradiation could be compared. Results: All lenses irradiated with a 6 kJ/cm2 reveal cataract development for radiation with 311 nm, 370 nm, and 460 nm. Both evaluations reveal that the 460 nm irradiation causes the most cataract. Conclusion: All investigated irradiation sources cause cataracts in porcine lenses-even blue visible light.

Evening home lighting adversely impacts the circadian system and sleep

The regular rise and fall of the sun resulted in the development of 24-h rhythms in virtually all organisms. In an evolutionary heartbeat, humans have taken control of their light environment with electric light. Humans are highly sensitive to light, yet most people now use light until bedtime. We evaluated the impact of modern home lighting environments in relation to sleep and individual-level light sensitivity using a new wearable spectrophotometer. We found that nearly half of homes had bright enough light to suppress melatonin by 50%, but with a wide range of individual responses (0–87% suppression for the average home). Greater evening light relative to an individual’s average was associated with increased wakefulness after bedtime. Homes with energy-efficient lights had nearly double the melanopic illuminance of homes with incandescent lighting. These findings demonstrate that home lighting significantly affects sleep and the circadian system, but the impact of lighting for a specific individual in their home is highly unpredictable.

Is Melatonin the Cornucopia of the 21st Century?

Melatonin, an indoleamine hormone produced and secreted at night by pinealocytes and extra-pineal cells, plays an important role in timing circadian rhythms (24-h internal clock) and regulating the sleep/wake cycle in humans. However, in recent years melatonin has gained much attention mainly because of its demonstrated powerful lipophilic antioxidant and free radical scavenging action. Melatonin has been proven to be twice as active as vitamin E, believed to be the most effective lipophilic antioxidant. Melatonin-induced signal transduction through melatonin receptors promotes the expression of antioxidant enzymes as well as inflammation-related genes. Melatonin also exerts an immunomodulatory action through the stimulation of high-affinity receptors expressed in immunocompetent cells. Here, we reviewed the efficacy, safety and side effects of melatonin supplementation in treating oxidative stress- and/or inflammation-related disorders, such as obesity, cardiovascular diseases, immune disorders, infectious diseases, cancer, neurodegenerative diseases, as well as osteoporosis and infertility.

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.

The Effect of a Screen Protector on Blue Light Intensity Emitted from Different Hand-held Devices

PURPOSE:

In response to growing concern about the effect of blue light on ocular tissue, companies have created mobile device screen protectors to block blue light. This project evaluates one of these screen protectors' ability to reduce blue light intensity.

METHODS:

The intensity of light at 450 nm from an iPhone 8, iPhone X, and iPad was measured in a dark room. The averages of three measurements were taken with and without the screen protector at different distances, settings of brightness, and Apple's night shift (NS) mode. Results were analyzed using paired t-tests.

RESULTS:

At 33 cm, 100% brightness, and 0% NS, the screen protector decreased intensity by 43.9%, 32.3%, and 34.9% for the iPhone 8, iPhone X, and iPad, respectively. At 33 cm and 100% brightness, increasing NS mode from 0% to 100% decreased intensity by 81.2%, 84.2%, and 86.5%. At 33 cm without NS, decreasing the brightness from 100% to 0% decreased intensity by 99.5%, 99.8%, and 97.8%.

CONCLUSIONS:

The screen protector decreased the intensity at 450 nm for every setting other than those at 0% brightness. Decreasing brightness and applying NS mode were more effective in reducing blue light. More research is needed to determine the benefits of decreasing blue light exposure from electronic devices.

Smartphones in mental health: a critical review of background issues, current status and future concerns

There has been increasing interest in the use of smartphone applications (apps) and other consumer technology in mental health care for a number of years. However, the vision of data from apps seamlessly returned to, and integrated in, the electronic medical record (EMR) to assist both psychiatrists and patients has not been widely achieved, due in part to complex issues involved in the use of smartphone and other consumer technology in psychiatry. These issues include consumer technology usage, clinical utility, commercialization, and evolving consumer technology. Technological, legal and commercial issues, as well as medical issues, will determine the role of consumer technology in psychiatry. Recommendations for a more productive direction for the use of consumer technology in psychiatry are provided.

An Efficient Method for LED Light Sources Characterization

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs’ power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED’s response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions.

Association between solar insolation and a history of suicide attempts in bipolar I disorder

In many international studies, rates of completed suicide and suicide attempts have a seasonal pattern that peaks in spring or summer. This exploratory study investigated the association between solar insolation and a history of suicide attempt in patients with bipolar I disorder. Solar insolation is the amount of electromagnetic energy from the Sun striking a surface area on Earth. Data were collected previously from 5536 patients with bipolar I disorder at 50 collection sites in 32 countries at a wide range of latitudes in both hemispheres. Suicide related data were available for 3365 patients from 310 onset locations in 51 countries. 1047 (31.1%) had a history of suicide attempt. There was a significant inverse association between a history of suicide attempt and the ratio of mean winter solar insolation/mean summer solar insolation. This ratio is smallest near the poles where the winter insolation is very small compared to the summer insolation. This ratio is largest near the equator where there is relatively little variation in the insolation over the year. Other variables in the model that were positively associated with suicide attempt were being female, a history of alcohol or substance abuse, and being in a younger birth cohort. Living in a country with a state-sponsored religion decreased the association. (All estimated coefficients p < 0.01). In summary, living in locations with large changes in solar insolation between winter and summer may be associated with increased suicide attempts in patients with bipolar disorder. Further investigation of the impacts of solar insolation on the course of bipolar disorder is needed.

Perspectives in affective disorders: Clocks and sleep

Mood disorders are often characterised by alterations in circadian rhythms, sleep disturbances and seasonal exacerbation. Conversely, chronobiological treatments utilise zeitgebers for circadian rhythms such as light to improve mood and stabilise sleep, and manipulations of sleep timing and duration as rapid antidepressant modalities. Although sleep deprivation ("wake therapy") can act within hours, and its mood-elevating effects be maintained by regular morning light administration/medication/earlier sleep, it has not entered the regular guidelines for treating affective disorders as a first-line treatment. The hindrances to using chronotherapeutics may lie in their lack of patentability, few sponsors to carry out large multi-centre trials, non-reimbursement by medical insurance and their perceived difficulty or exotic "alternative" nature. Future use can be promoted by new technology (single-sample phase measurements, phone apps, movement and sleep trackers) that provides ambulatory documentation over long periods and feedback to therapist and patient. Light combinations with cognitive behavioural therapy and sleep hygiene practice may speed up and also maintain response. The urgent need for new antidepressants should hopefully lead to reconsideration and implementation of these non-pharmacological methods, as well as further clinical trials. We review the putative neurochemical mechanisms underlying the antidepressant effect of sleep deprivation and light therapy, and current knowledge linking clocks and sleep with affective disorders: neurotransmitter switching, stress and cortico-limbic reactivity, clock genes, cortical neuroplasticity, connectomics and neuroinflammation. Despite the complexity of multi-system mechanisms, more insight will lead to fine tuning and better application of circadian and sleep-related treatments of depression.

Impact of long-term daylight deprivation on retinal light sensitivity, circadian rhythms and sleep during the Antarctic winter

Long-term daylight deprivation such as during the Antarctic winter has been shown to lead to delayed sleep timing and sleep fragmentation. We aimed at testing whether retinal sensitivity, sleep and circadian rest-activity will change during long-term daylight deprivation on two Antarctic bases (Concordia and Halley VI) in a total of 25 healthy crew members (mean age: 34 ± 11y; 7f). The pupil responses to different light stimuli were used to assess retinal sensitivity changes. Rest-activity cycles were continuously monitored by activity watches. Overall, our data showed increased pupil responses under scotopic (mainly rod-dependent), photopic (mainly L-/M-cone dependent) as well as bright-blue light (mainly melanopsin-dependent) conditions during the time without direct sunlight. Circadian rhythm analysis revealed a significant decay of intra-daily stability, indicating more fragmented rest-activity rhythms during the dark period. Sleep and wake times (as assessed from rest-activity recordings) were significantly delayed after the first month without sunlight (p < 0.05). Our results suggest that during long-term daylight deprivation, retinal sensitivity to blue light increases, whereas circadian rhythm stability decreases and sleep-wake timing is delayed.

Effects of blue- and red-enriched light on attention and sleep in typically developing adolescents

Differential effects of blue- and red-enriched light on attention and sleep have been primarily described in adults. In our cross-over study in typically developing adolescents (11-17 years old), we found attention enhancing effects of blue- compared to red-enriched light in the morning (high intensity of ca. 1000 lx, short duration: <1 h) in two of three attention tasks: e.g. better performance in math tests and reduced reaction time variability in a computerized attention test. In our pilot study, actigraphy measures of sleep indicated slight benefits for red- compared to blue-enriched light in the evening: tendencies toward a lower number of phases with movement activity after sleep onset in the complete sample and shorter sleep onset latency in a subgroup with later evening exposure times. These findings point to the relevance of light concepts regarding attention and sleep in typically developing adolescents. Such concepts should be developed and tested further in attention demanding contexts (at school) and for therapeutic purposes in adolescents with impaired attention or impaired circadian rhythms.

Internet use by older adults with bipolar disorder: international survey results

Background

The world population is aging and the number of older adults with bipolar disorder is increasing. Digital technologies are viewed as a framework to improve care of older adults with bipolar disorder. This analysis quantifies Internet use by older adults with bipolar disorder as part of a larger survey project about information seeking.

Methods

A paper-based survey about information seeking by patients with bipolar disorder was developed and translated into 12 languages. The survey was anonymous and completed between March 2014 and January 2016 by 1222 patients in 17 countries. All patients were diagnosed by a psychiatrist. General estimating equations were used to account for correlated data.

Results

Overall, 47% of older adults (age 60 years or older) used the Internet versus 87% of younger adults (less than 60 years). More education and having symptoms that interfered with regular activities increased the odds of using the Internet, while being age 60 years or older decreased the odds. Data from 187 older adults and 1021 younger adults were included in the analysis excluding missing values.

Conclusions

Older adults with bipolar disorder use the Internet much less frequently than younger adults. Many older adults do not use the Internet, and technology tools are suitable for some but not all older adults. As more health services are only available online, and more digital tools are developed, there is concern about growing health disparities based on age. Mental health experts should participate in determining the appropriate role for digital tools for older adults with bipolar disorder.

Healthy hearts at hectic pace: From daily life stress to abnormal cardiomyocyte function and arrhythmias

The hectic pace of contemporary life is a major source of acute and chronic stress, which may have a deleterious impact on body health . In the field of cardiovascular disease, acute emotional stress has been associated with coronary spasm and Takotsubo cardiomyopathy, whereas the manifestations of chronic stress have been overlooked, and most underlying pathophysiology remains to be elucidated. Chronic stress affects the neuronal circuitry composed of cortico-limbic structures and the nuclei regulating autonomic function, eliciting a sympatho-vagal imbalance, characterised by adrenergic activation and vagal withdrawal. Sympathetic terminals are connected to cardiomyocytes in a quasi-synaptic way, producing the so called 'neuro-cardiac junction'. During chronic stress, norepinephrine release is increased, leading to overstimulation of cardiomyocytes via β₁-adrenergic receptors, influencing mainly calcium dynamics, and β₂-adrenergic receptors, which control housekeeping functions. The circadian rhythm of cardiomyocytes is then impaired, with elongation of the catabolic ('light' phase) over the anabolic ('nocturnal') phase. This leads to a depletion of cell energy storage, and a decreased turnover of cell constituents. Even cell interactions are affected, as coupling between cardiomyocytes decreases while coupling between cardiomyocytes and fibroblasts increases. The ultimate results are changes in the shape and velocity of action potential, fibroblast activation and deposition of extracellular matrix. These alterations may predispose to arrhythmias and may favour the development of a stress-related cardiomyopathy. A better comprehension of this cascade of events may allow us to identify screening protocols and treatment strategies (meditation, yoga, physical activity, psychological assistance, β-blockers) to prevent or relieve ongoing cardiac damage.