Relationship between sunlight and the age of onset of bipolar disorder: an international multisite study

Novel multimodal precision medicine approaches and the relevance of developmental trajectories in bipolar disorder

There is a pressing need to establish objective measures to improve diagnosis, prediction, prevention and treatment of bipolar disorder (BD). Multimodal artificial intelligence (AI) tools could provide these means by incorporating various layers of data orthogonally related to BD, including genomics and other omics, environmental exposures, imaging measures, electronic health records, cognition, sensing devices and clinical variables. These rapidly evolving AI models hold promise to capture the multidimensional complexity of BD and delineate clinically relevant developmental trajectories that could guide clinical care and therapeutic strategies. In this review, we describe the potential of mapping developmental trajectories underlying BD, outline how novel multimodal models could improve the prediction of BD and related outcomes, and discuss specific clinical use cases and key ethical and practical challenges regarding the development and potential implementation of these multimodal AI solutions to advance precision medicine approaches in BD.

The Impact of Seasonality on Mental Health Disorders: A Narrative Review and Extension of the Immunoseasonal Theory

The impact of weather on mental illness is widely debated, but the mechanism of this relationship remains unclear. The immunoseasonal theory suggests that in winter, a T-helper 1 (Th1) response predominates, impairing Prefrontal Cortex (PFC) control, which exacerbates symptoms of depression, while after it, in summer, a Th2 response predominates in immunologically prone individuals, activating cortical and mesolimbic centers, which can exacerbate symptoms of psychosis. In this paper, we aim to describe the validity of this theory through a narrative review of data related to weather and immunology in psychiatry. This review extends existing literature by integrating immunological findings with psychiatric seasonality research, offering a mechanistic perspective that links Th1/Th2 shifts to specific symptom exacerbations. Winter Th1 severity may worsen depression and anxiety, while summer Th2 dominance appears to be associated with exacerbations of schizophrenia, mania, impulsivity, and suicide risk. It is possible that the mechanism of Th1 response potentiation and deterioration of PFC function is common to most psychiatric entities and is nonspecific. This suggests that seasonal immune dysregulation may play a broader role in psychiatric disorders than previously recognized, challenging the idea that seasonality impacts only selected conditions. Characteristic dysfunctions within an individual determine further differences in clinical manifestations. The mechanism of Th2 potentiation may not be limited to mania and psychosis but may also be associated with increased impulsivity and suicide risk. If the immunoseasonal theory is confirmed, selected immunological markers could be used not only in the diagnosis of psychiatric exacerbations but also in predicting symptom fluctuations and tailoring treatment strategies. This could enable more personalized interventions, such as seasonally adjusted medication dosing or targeted anti-inflammatory therapies. While this mechanism seems plausible, further research, especially analyzing markers of inflammatory and anti-inflammatory responses, is needed to better understand and confirm it.

Milk derived extracellular vesicle uptake in human microglia regulates the DNA methylation machinery : Short title: milk-derived extracellular vesicles and the epigenetic machinery

Mammalian milk contains milk-derived extracellular vesicles (MEVs), a group of biological nanovesicles that transport macromolecules. Their ability to cross the blood brain barrier and the presence of cargo capable of modifying gene function have led to the hypothesis that MEVs may play a role in brain function and development. Here, we investigated the uptake of MEVs by human microglia cells in vitro and explored the functional outcomes of MEV uptake. We examined the expression of the miR-148/152 family, highly abundant MEV microRNAs, that directly suppress the translation of DNA methyltransferase (DNMT) enzymes crucial for catalyzing DNA methylation modifications. We also measured phenotypic and inflammatory gene expression in baseline homeostatic and IFN-γ primed microglia to determine if MEVs induce anti-inflammatory effects. We found that MEVs are taken up and localize in baseline and primed microglia. In baseline microglia, MEV supplementation reduced miR-148a-5P levels, increased DNMT1 transcript, protein abundance, and enzymatic activity, compared to cells that did not receive MEVs. In primed microglia, MEV supplementation decreased miR-148a-5P levels and increased DNMT1 protein abundance, but DNMT1 transcript and enzymatic levels remained unchanged. Contrary to predictions, MEV supplementation failed to attenuate pro-inflammatory IL1β expression in primed microglia. This study provides the first evidence of MEV uptake by a brain macrophage, suggesting a potential role in regulating epigenetic machinery and neuroimmune modulation.

Relationship between sun exposure and seasonal affective disorder symptoms in rural older people with different personalities: a cross-sectional study

OBJECTIVES

Evidence suggests that environmental support, personality traits, and psychological factors can influence seasonal changes in human mood and behavior, particularly in rural middle-aged women and older people. This study aimed to quantify the associations between personality traits, seasonal affective disorder symptoms, and sun exposure in rural older people.

METHODS

This study is a cross-sectional analytical study, the participants were 300 rural older persons from 12 natural villages and 5 geriatric service centers in 4 different cities in Jiangxi Province, China. The Eysenck Personality Questionnaire (EPQ), the Personal Inventory of Depression and Seasonal Affective Disorder (PIDS-SA-SimpChi), and the Sunlight Exposure Scale were used to conduct follow-up interviews throughout the year. Spatial analysis was performed using ArcGIS and Geodetic Probes. The data were analyzed using SPSS 21 and Amos 23.0 mediated models.

RESULTS

Rural older people with low sun exposure exhibited higher personality trait scores (p < 0.001). Personality traits were directly associated with seasonal affective disorder symptoms(p < 0.01); Sun exposure mediated this effect in rural older people (p < 0.05).

CONCLUSION

High-scoring personalities are more typical of rural older people with low sun exposure, and there is a greater risk of emotional and behavioral instability. Latitudinal differences are not a determinant of SAD. Increased sun exposure is associated with symptom relief. The promotion of light therapy devices in rural areas with low sunlight is warranted.

Vitamin D Status in Bipolar Disorder

Vitamin D status may impact acute affective symptomatology and the severity of symptoms in patients with bipolar disorder (BD). Therefore, this cross-sectional study analyzed 25(OH)D, 24,25(OH)2D, and the vitamin D metabolite ratio (VMR) in BD and correlated the results with clinical affective symptomatology and functionality. The inactive precursor 25(OH)D, and its principal catabolite 24,25(OH)2D, were measured simultaneously with a validated liquid chromatography-tandem mass spectrometry method in 170 BD outpatients and 138 healthy controls. VMR was calculated as follows: VMR = 100×(24,25(OH)2D/25(OH)D). The psychometric assessment comprised: Beck Depression Inventory-II, Hamilton Depression Rating Scale, Young Mania Rating Scale, Global Assessment of Functioning, and number of suicide attempts. We did not find a significant difference between patients and controls in the concentrations of 25(OH)D and 24,25(OH)2D. Additionally, the VMR was comparable in both groups. The calculations for the clinical parameters showed a negative correlation between the Young Mania Rating Scale and 24,25(OH)2D (r = -0.154, p = 0.040), as well as the Young Mania Rating Scale and the VMR (r = -0.238, p = 0.015). Based on the small effect size and the predominantly euthymic sample, further exploration in individuals with manic symptoms would be needed to confirm this association. In addition, long-term clinical markers and an assessment in different phases of the disease may provide additional insights.

Annual Transmittance Behavior of Light-Transmitting Concrete with Optical Fiber Bundles

This study characterizes the transmittance behavior of structural light-transmitting concrete under natural sunlight. The experimentation involves the use of a novel test setup and a detailed analysis considering the variation and dependence on time of day, month of the year and seasonal variations. The test set consisted of 28 variations of fiber configurations, with two different diameters, spacing and bundling techniques used to increase the area of fibers while maintaining spacing to aid the placing of concrete without compromising on transmittance. The study provides a real-time observational understanding of the behavior of light-transmitting concrete, a result usually obtained by modelling and simulation. The statistical analysis helps in understanding the impact of various variables as well as their interrelationships, which can help in design optimization. Based on the behavior as well as the stipulations of standards, the applicability of the material to various structural applications has been identified.

Prevalence and characteristics of unipolar mania in a low-income country setting: population-based data from the Butajira cohort, rural Ethiopia

PURPOSE

Previous research suggests unipolar mania, i.e., bipolar disorder without depression, to be more common in low-income countries. However, longitudinal population-based studies on unipolar mania from low-income countries are lacking. This study therefore examined unipolar mania, in Butajira, Ethiopia, and associations with possible determinants.

METHODS

Key informants and 68,378 screenings with the Composite International Diagnostic Interviews (CIDI 2.1) identified suspected cases of bipolar disorder. Diagnosis was confirmed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN 2.1) (n = 2,285). 315 participants with bipolar disorder were recruited and followed up for an average of 2.5 years. Unipolar mania was defined when illness episodes consisted of at least two manic relapses. 240 cases had sufficient data to ascertain course of disorder.

RESULTS

41.7% (100 of 240 cases) of participants had unipolar mania. Unipolar mania was associated with less suicidal ideation (0% vs. 26.4%, p < 0.001), less suicidal thoughts (occasionally/often: 1%/3% vs. 19.6%/21%, p < 0.001), and less history of suicide attempt (2% vs. 11.6%, p = 0.01). The participants with unipolar mania tended to have better social functioning (OR = 2.05, p = 0.07) and less alcohol use (20.8% vs. 31.4%, p = 0.07). The study was partly based on retrospective data liable to recall bias. Some cases defined as unipolar mania in our study may later develop depression.

CONCLUSION

Previous cross-sectional studies finding high proportions of unipolar mania in low-income countries appear supported. Unipolar mania trended towards better social functioning and was associated with lower suicidality. Future unipolar mania specifications could inform treatment and prognostic estimates of bipolar disorder.

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.

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.

Variations in seasonal solar insolation are associated with a history of suicide attempts in bipolar I disorder

Background

Bipolar disorder is associated with circadian disruption and a high risk of suicidal behavior. In a previous exploratory study of patients with bipolar I disorder, we found that a history of suicide attempts was associated with differences between winter and summer levels of solar insolation. The purpose of this study was to confirm this finding using international data from 42% more collection sites and 25% more countries.

Methods

Data analyzed were from 71 prior and new collection sites in 40 countries at a wide range of latitudes. The analysis included 4876 patients with bipolar I disorder, 45% more data than previously analyzed. Of the patients, 1496 (30.7%) had a history of suicide attempt. Solar insolation data, the amount of the sun’s electromagnetic energy striking the surface of the earth, was obtained for each onset location (479 locations in 64 countries).

Results

This analysis confirmed the results of the exploratory study with the same best model and slightly better statistical significance. There was a significant inverse association between a history of suicide attempts and the ratio of mean winter insolation to mean summer insolation (mean winter insolation/mean summer insolation). This ratio is largest near the equator which has little change in solar insolation over the year, and smallest near the poles where the winter insolation is very small compared to the summer insolation. Other variables in the model associated with an increased risk of suicide attempts were a history of alcohol or substance abuse, female gender, and younger birth cohort. The winter/summer insolation ratio was also replaced with the ratio of minimum mean monthly insolation to the maximum mean monthly insolation to accommodate insolation patterns in the tropics, and nearly identical results were found. All estimated coefficients were significant at p < 0.01.

Conclusion

A large change in solar insolation, both between winter and summer and between the minimum and maximum monthly values, may increase the risk of suicide attempts in bipolar I disorder. With frequent circadian rhythm dysfunction and suicidal behavior in bipolar disorder, greater understanding of the optimal roles of daylight and electric lighting in circadian entrainment is needed.

Enlightened: addressing circadian and seasonal changes in photoperiod in animal models of bipolar disorder

Bipolar disorders (BDs) exhibit high heritability and symptoms typically first occur during late adolescence or early adulthood. Affected individuals may experience alternating bouts of mania/hypomania and depression, with euthymic periods of varying lengths interspersed between these extremes of mood. Clinical research studies have consistently demonstrated that BD patients have disturbances in circadian and seasonal rhythms, even when they are free of symptoms. In addition, some BD patients display seasonal patterns in the occurrence of manic/hypomanic and depressive episodes as well as the time of year when symptoms initially occur. Finally, the age of onset of BD symptoms is strongly influenced by the distance one lives from the equator. With few exceptions, animal models useful in the study of BD have not capitalized on these clinical findings regarding seasonal patterns in BD to explore molecular mechanisms associated with the expression of mania- and depression-like behaviors in laboratory animals. In particular, animal models would be especially useful in studying how rates of change in photoperiod that occur during early spring and fall interact with risk genes to increase the occurrence of mania- and depression-like phenotypes, respectively. Another unanswered question relates to the ways in which seasonally relevant changes in photoperiod affect responses to acute and chronic stressors in animal models. Going forward, we suggest ways in which translational research with animal models of BD could be strengthened through carefully controlled manipulations of photoperiod to enhance our understanding of mechanisms underlying seasonal patterns of BD symptoms in humans. In addition, we emphasize the value of incorporating diurnal rodent species as more appropriate animal models to study the effects of seasonal changes in light on symptoms of depression and mania that are characteristic of BD in humans.

Rate of change in solar insolation is a hidden variable that influences seasonal alterations in bipolar disorder

The consensus in the literature is that bipolar disorder is seasonal. We argue that there is finer detail to seasonality and that changes in mood and energy in bipolar disorder are dictated by the rate of change of solar insolation.

Sunlight and health: shifting the focus from vitamin D3 to photobiomodulation by red and near-infrared light

Both sun exposure and serum vitamin D levels have been associated with lower risks of all-cause mortality and chronic age-related diseases, e.g., cancer, diabetes and cardiovascular disease, in epidemiological studies. These associations have mainly been ascribed to beneficial effects of vitamin D. However, a vast body of randomized controlled trials (RCTs) and Mendelian randomization studies have failed to confirm any major health benefits from vitamin D supplementation. In this review, we present tentative evidence showing that red and near-infrared light, both being present in sunlight, could explain the associations between sunlight exposure and better health status. Body irradiation with red and near-infrared light, usually termed as photobiomodulation (PBM), has demonstrated beneficial effects in animal models of chronic diseases. Beyond this, preliminary evidence from RCTs suggest potential clinical benefit from PBM for chronic diseases. PBM is currently being investigated in many pre-registered clinical trials, results of which will eventually clarify the role of red and near-infrared light in the prevention and treatment of common age-related chronic diseases.

Association Between Outdoor Activity and Insufficient Sleep in Chinese School-Aged Children

Background

The aim of this study was to explore the relationship between outdoor activity (OA) and insufficient sleep duration (ISD) among Chinese children and to assess the potential age- and gender-specific effects.

Material/Methods

A national sample of 62 517 children aged 6–17 years were recruited from 7 provinces of China in the autumn of 2013. Children and their caregivers reported daily sleep duration (<7 h, 7–9 h and ≥9 h), daily OA time (<1 h, 1–2 h, and ≥2 h), and other behavior and demographic information by standardized questionnaire. ISD was defined as <9 h/day. Logistic regression analysis was used to evaluate the relationship between ISD and OA.

Results

In total, 46 639 children (50.9% boys) completed this survey. The prevalence of ISD was 74.9% (73.7% in boys and 76.1% in girls). Stratified by age, compared with <1 h OA, the odds ratios for ISD were 0.67 (95% confidence interval: 0.62–0.72, aged 6–13 years) and 0.69 (0.49–0.98, 14–17 years) in the ≥2 h OA group; 0.91 (0.85–0.97, 6–13 years) and 0.73 (0.54–0.97, 14–17 years) in the 1–2 h OA group. Further stratified by gender, we found similar trends for both boys and girls in each age group, although some results became non-significant.

Conclusions

Adequate OA time per day is associated with decreased risks for ISD among children aged 6–17 years, but age and gender can modify the association.

Influence of birth cohort on age of onset cluster analysis in bipolar I disorder

Purpose:

Two common approaches to identify subgroups of patients with bipolar disorder are clustering methodology (mixture analysis) based on the age of onset, and a birth cohort analysis. This study investigates if a birth cohort effect will influence the results of clustering on the age of onset, using a large, international database.

Methods:

The database includes 4037 patients with a diagnosis of bipolar I disorder, previously collected at 36 collection sites in 23 countries. Generalized estimating equations (GEE) were used to adjust the data for country median age, and in some models, birth cohort. Model-based clustering (mixture analysis) was then performed on the age of onset data using the residuals. Clinical variables in subgroups were compared.

Results:

There was a strong birth cohort effect. Without adjusting for the birth cohort, three subgroups were found by clustering. After adjusting for the birth cohort or when considering only those born after 1959, two subgroups were found. With results of either two or three subgroups, the youngest subgroup was more likely to have a family history of mood disorders and a first episode with depressed polarity. However, without adjusting for birth cohort (three subgroups), family history and polarity of the first episode could not be distinguished between the middle and oldest subgroups.

Conclusion:

These results using international data confirm prior findings using single country data, that there are subgroups of bipolar I disorder based on the age of onset, and that there is a birth cohort effect. Including the birth cohort adjustment altered the number and characteristics of subgroups detected when clustering by age of onset. Further investigation is needed to determine if combining both approaches will identify subgroups that are more useful for research.

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.

Effects of light on aging and longevity

Increasing evidence suggests an important role for light in regulation of aging and longevity. UV radiation is a mutagen that can promote aging and decrease longevity. In contrast, NIR light has shown protective effects in animal disease models. In invertebrates, visible light can shorten or extend lifespan, depending on the intensity and wavelength composition. Visible light also impacts human health, including retina function, sleep, cancer and psychiatric disorders. Possible mechanisms of visible light include: controlling circadian rhythms, inducing oxidative stress, and acting through the retina to affect neuronal circuits and systems. Changes in artificial lighting (e.g., LEDs) may have implications for human health. It will be important to further explore the mechanisms of how light affects aging and longevity, and how light affects human health.

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.

Maximum Temperature and Solar Radiation as Predictors of Bipolar Patient Admission in an Emergency Psychiatric Ward

Environmental variables can regulate behavior in healthy subjects. Recently, some authors investigated the role of meteorological variables in bipolar patients with an impact on both the onset and course of bipolar disorder (BD). The aim of this study was to investigate the impact of meteorological variables and other indexes in bipolar hospitalized patients. We examined all patients admitted to the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital, Orbassano (Turin, Italy) from September 2013 to August 2015, collecting several socio-demographic and clinical characteristics. Seven hundred and thirty patients were included. Compared to the day of admission of control individuals, patients with BD were admitted on a day that presented higher minimum, medium, and maximum temperature, higher maximum humidity, higher solar radiation, and higher hours of sunshine. After logistic regression analysis, admissions to the emergency psychiatric ward due to a primary diagnosis of BD were associated with maximum temperature and solar radiation. The current study provides a novel perspective on the question surrounding seasonal mood patterns in patients with BD. A greater awareness of all possible precipitating factors is needed to inform self-management and psycho-educational programs as well as to improve resilience regarding affective recurrences in the clinical practice.

Seasonality in bipolar disorder: Effect of sex and age

BACKGROUND

Mood episodes in bipolar disorder (BD) are reported to exhibit a seasonal pattern (SP). However, it is unclear whether this pattern is influenced by a patient's sex and age.

METHODS

In this nationwide registry study, we examined all inpatient treatments due to a manic (F31.0-2), depressive (F31.3-5) or mixed (F31.6) BD-episode in Austria for 2001-2014. Calculations were based on directly age-standardized rates and seasonality was analyzed on a monthly basis.

RESULTS

The database comprised 60,607 admissions (35.8% men). SP were shown for women during manic (summer-autumn), depressive (winter) and mixed (summer) episodes, for men only during manic (summer) episodes. However, no significant sex differences (manic p = 0.101, depressive p = 0.295, mixed p = 0.622 episode) were found. Women at young age (15-35 years) seemed to be more vulnerable to a SP in manic and mixed episodes.

LIMITATIONS

Only aggregated patient data of inpatient treatments and no single case histories were available.

CONCLUSIONS

In this nationwide registry study, a distinct SP could be shown for manic episodes in men and women, as well as a SP for depressive and mixed episodes in women. As no significant difference in any BD-subgroup could be observed, the effect of sex on the SP seems to be small, if existing at all. However, when taking age into account, we observed a higher likelihood for a SP in young women. Single case studies with information on possible further influencing factors (e.g. medication use) might help to clarify the impact of sex and age on SP in more detail.

Solar insolation in springtime influences age of onset of bipolar I disorder

OBJECTIVE

To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder.

METHOD

Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density.

RESULTS

There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001).

CONCLUSION

A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.

Recent advances in the understanding and management of bipolar disorder in adults

This article focuses on some aspects of recent progress in the neurobiology and treatment of bipolar disorder (BD) in adults. A molecular-genetic approach to the etiopathogenesis of the illness resulted in the findings of a genetic overlap between BD and other major psychiatric disorders. Furthermore, a poly-gene-environmental interaction in the development of the illness has been demonstrated. For the management of BD, new drugs with putative mood-stabilizing properties have been introduced in the past two decades. However, none of these can surpass lithium, the prototype mood-stabilizer, still considered the most specific drug for BD. Recent research on lithium, besides providing new data on the neurobiology of BD, has confirmed anti-suicidal, immunomodulatory, and neuroprotective properties of this drug.

Meteorological analysis of symptom data for people with seasonal affective disorder

It is thought that variation in natural light levels affect people with Seasonal Affective Disorder (SAD). Several meteorological factors related to luminance can be forecast but little is known about which factors are most indicative of worsening SAD symptoms. The aim of this meteorological analysis is to determine which factors are linked to SAD symptoms. The symptoms of 291 individuals with SAD in and near Groningen have been evaluated over the period 2003-2009. Meteorological factors linked to periods of low natural light (sunshine, global radiation, horizontal visibility, cloud cover and mist) and others (temperature, humidity and pressure) were obtained from weather observation stations. A Bayesian zero adjusted auto-correlated multilevel Poisson model was carried out to assess which variables influence the SAD symptom score BDI-II. The outcome of the study suggests that the variable sunshine duration, for both the current and previous week, and global radiation for the previous week, are significantly linked to SAD symptoms.

Bipolar disorder in Asia: Illness course and contributing factors

BACKGROUND

Epidemiological studies analysing the course of Bipolar Disorder (BD) are relatively rare in the Asian context, contributing to the uncertainty regarding the prevalent course patterns and factors influencing such patterns. The current review identifies the regional characteristics of BD course patterns and the associated factors.

METHODS

A review of the existing literature was done using 'PubMed' and 'Cochrane' databases which yielded 145 studies including those from all 48 Asian countries. Relevant discussions from the Western literature were incorporated.

RESULTS

Regional and cross-national studies reveal a mania-predominant course in BD in Asian countries. Prolonged depressive episodes and comorbid anxiety disorders worsen the course of BD-II. Certain risk factors such as the young age of onset and greater episode frequency are useful predictors of bipolar diatheses. Substance use disorder comorbidity is more prevalent in males whereas depression and suicidal behaviours are more frequent in females with BD. Comorbid anxiety and personality disorders also encumber the illness course. Logistic reasons and ignorance of side-effects were specifically associated with poor adherence. An 'eveningness' chronotype and poor sleep quality were associated with frequent recurrences. Seasonal patterns vary among men and women, especially for depressive episodes.

LIMITATIONS

The effects of treatment and childhood BD course features were not discussed.

CONCLUSIONS

There are region-specific characteristics in bipolar illness course and factors influencing such course patterns compared to the rest of the World. Future research from Asia shall attempt to study the neurobiological underpinnings of such characteristics and plan appropriate strategies to address the same.

White Matter Tract Integrity in Alzheimer's Disease vs. Late Onset Bipolar Disorder and Its Correlation with Systemic Inflammation and Oxidative Stress Biomarkers

Background: Late Onset Bipolar Disorder (LOBD) is the development of Bipolar Disorder (BD) at an age above 50 years old. It is often difficult to differentiate from other aging dementias, such as Alzheimer's Disease (AD), because they share cognitive and behavioral impairment symptoms.

Objectives: We look for WM tract voxel clusters showing significant differences when comparing of AD vs. LOBD, and its correlations with systemic blood plasma biomarkers (inflammatory, neurotrophic factors, and oxidative stress).

Materials: A sample of healthy controls (HC) (n = 19), AD patients (n = 35), and LOBD patients (n = 24) was recruited at the Alava University Hospital. Blood plasma samples were obtained at recruitment time and analyzed to extract the inflammatory, oxidative stress, and neurotrophic factors. Several modalities of MRI were acquired for each subject,

Methods: Fractional anisotropy (FA) coefficients are obtained from diffusion weighted imaging (DWI). Tract based spatial statistics (TBSS) finds FA skeleton clusters of WM tract voxels showing significant differences for all possible contrasts between HC, AD, and LOBD. An ANOVA F-test over all contrasts is carried out. Results of F-test are used to mask TBSS detected clusters for the AD > LOBD and LOBD > AD contrast to select the image clusters used for correlation analysis. Finally, Pearson's correlation coefficients between FA values at cluster sites and systemic blood plasma biomarker values are computed.

Results: The TBSS contrasts with by ANOVA F-test has identified strongly significant clusters in the forceps minor, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and cingulum gyrus. The correlation analysis of these tract clusters found strong negative correlation of AD with the nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) blood biomarkers. Negative correlation of AD and positive correlation of LOBD with inflammation biomarker IL6 was also found.

Conclusion: TBSS voxel clusters tract atlas localizations are consistent with greater behavioral impairment and mood disorders in LOBD than in AD. Correlation analysis confirms that neurotrophic factors (i.e., NGF, BDNF) play a great role in AD while are absent in LOBD pathophysiology. Also, correlation results of IL1 and IL6 suggest stronger inflammatory effects in LOBD than in AD.

Bipolar disorders: is there an influence of seasonality or photoperiod?

Objective:

To increase understanding of the influence of photoperiod variation in patients with bipolar disorders.

Methods:

We followed a sample of Italian bipolar patients over a period of 24 months, focusing on inpatients. All patients admitted to the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital in Orbassano (Turin, Italy) between September 1, 2013 and August 31, 2015 were recruited. Sociodemographic and clinical data were collected.

Results:

Seven hundred and thirty patients were included. The admission rate for bipolar patients was significantly higher during May, June and July, when there was maximum sunlight exposure, although no seasonal pattern was found. Patients with (hypo)manic episodes were admitted more frequently during the spring and during longer photoperiods than those with major depressive episodes.

Conclusions:

Photoperiod is a key element in bipolar disorder, not only as an environmental factor but also as an important clinical parameter that should be considered during treatment.

More childhood onset bipolar disorder in the United States than Canada or Europe: Implications for treatment and prevention

Evidence of a high or increasing incidence of childhood onset bipolar disorder in the United States (US) has been viewed skeptically. Here we review evidence that childhood onsets of bipolar disorder are more common in the US than in Europe, treatment delays are longer, and illness course is more adverse and difficult. Epidemiological data and studies of offspring at high risk also support these findings. In our cohort of outpatients with bipolar disorder, two of the major vulnerability factors for early onset - genetics and environmental adversity in childhood - were also greater in the US than in Europe. An increased familial loading for multiple psychiatric disorders was apparent in 4 generations of the family members of the patients from the US, and that familial burden was linked to early onset bipolar disorder. Since both early onset and treatment delay are risk factors for a poor outcome in adulthood, new clinical, research, and public health initiatives are needed to begin to address and ameliorate this ongoing and potentially devastating clinical situation.

Predominant mania course in Indian patients with bipolar I disorder

Many long-term follow-up studies suggest that bipolar disorder (BD) is highly recurrent and that depressive episodes are commoner than hypomania/manic episodes. However, some studies from tropical countries including India suggest that the patients experience a greater proportion of manic episodes than depressive episodes. The aim of the present study was to examine the course of BD type 1 (BD I) in a sample of hospitalized Indian subjects. We examined the clinical course of 285 BD I subjects with at least 5 years of illness using standard life charting method. These subjects were hospitalized between October 2010 and October 2012. The predominant polarity (having at least two-thirds of their lifetime episodes at one polarity) was mania (79%). Unipolar mania (≥ 3 mania episodes and no episodes of depression) was observed in 48% of the subjects. The frequency of rapid cycling course was noted in 2.5% of the subjects. Predominant manic polarity group had the illness onset mostly with a manic episode (88.9%) and the predominant depressive polarity group with a depressive episode (73.8%). Mania was the predominant polarity with a high rate of unipolar mania and a majority of the subjects had greater number of manic episodes than depressive/mixed episodes. The onset polarity determined the predominant polarity during the course of illness. Predominantly, mania course could have significant implications in the treatment of bipolar disorder.

Discrimination between Alzheimer's Disease and Late Onset Bipolar Disorder Using Multivariate Analysis

Background

Late onset bipolar disorder (LOBD) is often difficult to distinguish from degenerative dementias, such as Alzheimer disease (AD), due to comorbidities and common cognitive symptoms. Moreover, LOBD prevalence in the elder population is not negligible and it is increasing. Both pathologies share pathophysiological neuroinflammation features. Improvements in differential diagnosis of LOBD and AD will help to select the best personalized treatment.

Objective

The aim of this study is to assess the relative significance of clinical observations, neuropsychological tests, and specific blood plasma biomarkers (inflammatory and neurotrophic), separately and combined, in the differential diagnosis of LOBD versus AD. It was carried out evaluating the accuracy achieved by classification-based computer-aided diagnosis (CAD) systems based on these variables.

Materials

A sample of healthy controls (HC) (n = 26), AD patients (n = 37), and LOBD patients (n = 32) was recruited at the Alava University Hospital. Clinical observations, neuropsychological tests, and plasma biomarkers were measured at recruitment time.

Methods

We applied multivariate machine learning classification methods to discriminate subjects from HC, AD, and LOBD populations in the study. We analyzed, for each classification contrast, feature sets combining clinical observations, neuropsychological measures, and biological markers, including inflammation biomarkers. Furthermore, we analyzed reduced feature sets containing variables with significative differences determined by a Welch’s t-test. Furthermore, a battery of classifier architectures were applied, encompassing linear and non-linear Support Vector Machines (SVM), Random Forests (RF), Classification and regression trees (CART), and their performance was evaluated in a leave-one-out (LOO) cross-validation scheme. Post hoc analysis of Gini index in CART classifiers provided a measure of each variable importance.

Results

Welch’s t-test found one biomarker (Malondialdehyde) with significative differences (p < 0.001) in LOBD vs. AD contrast. Classification results with the best features are as follows: discrimination of HC vs. AD patients reaches accuracy 97.21% and AUC 98.17%. Discrimination of LOBD vs. AD patients reaches accuracy 90.26% and AUC 89.57%. Discrimination of HC vs LOBD patients achieves accuracy 95.76% and AUC 88.46%.

Conclusion

It is feasible to build CAD systems for differential diagnosis of LOBD and AD on the basis of a reduced set of clinical variables. Clinical observations provide the greatest discrimination. Neuropsychological tests are improved by the addition of biomarkers, and both contribute significantly to improve the overall predictive performance.

Interaction between SLC6A4 promoter variants and childhood trauma on the age at onset of bipolar disorders

Age at onset (AAO) of bipolar disorders (BD) could be influenced both by a repeat length polymorphism (5HTTLPR) in the promoter region of the serotonin transporter gene (SLC6A4) and exposure to childhood trauma. We assessed 308 euthymic patients with BD for the AAO of their first mood episode and childhood trauma. Patients were genotyped for the 5HTTLPR (long/short variant) and the rs25531. Genotypes were classified on functional significance (LL, LS, SS). A sample of 126 Brazilian euthymic patients with BD was used for replication. In the French sample, the correlation between AAO and trauma score was observed only among 'SS' homozygotes (p = 0.002) but not among 'L' allele carriers. A history of at least one trauma decreased the AAO only in 'SS' homozygotes (p = 0.001). These results remained significant after correction using FDR. Regression models suggested an interaction between emotional neglect and 'SS' genotype on the AAO (p = 0.009) and no further interaction with other trauma subtypes. Partial replication was obtained in the Brazilian sample, showing an interaction between emotional abuse and 'LS' genotype on the AAO (p = 0.02). In conclusion, an effect of childhood trauma on AAO of BD was observed only in patients who carry a specific stress responsiveness-related SLC6A4 promoter genotype.

Comparison of precipitating factors for mania and partial seizures: Indicative of shared pathophysiology?

OBJECTIVES

Mania in bipolar disorder (BD) and partial (focal) seizures (PS) arising from the temporal lobes, have a number of similarities. Typically, a chronic course of the disorders is punctuated by acute illness episodes. Common features of episodes may include sensory, perceptual, cognitive and affective changes. Both respond to anticonvulsant treatment. Common mechanisms imputed include neurotransmitters and kindling processes. Further investigation may improve understanding of the occurrence of both mania and PS, casting light on the relevance of temporal lobe mediated processes and pathology. One avenue of investigation is to compare aetiological factors and determine the extent of overlap which may indicate shared brain localization or pathophysiology. Aetiology includes predisposing, precipitating or perpetuating factors. This paper examines the literature on precipitating factors of mania, first or subsequent episode, and of PS in diagnosed epilepsy, which is the second or subsequent seizure, to identify the extent and nature of their overlap.

METHOD

Narrative review based on a literature search of PubMed and Google Scholar.

RESULTS

Precipitating factors for both mania and PS were stress, sleep deprivation, antidepressant medication and, tentatively, emotion. For mania alone, goal-attainment events, spring and summer season, postpartum, and drugs include steroids and stimulants. For PS alone, winter season, menstruation and specific triggers in complex reflex epilepsies. Those not substantiated include lunar phase and menopause. A wide range of chemicals may provoke isolated seizures but by definition epilepsy requires at least two seizures.

CONCLUSIONS

The overlap of precipitating factors in mania and PS imply that common brain processes may contribute to both, consistent with findings from neuroscience research.

Influence of light exposure during early life on the age of onset of bipolar disorder

BACKGROUND

Environmental conditions early in life may imprint the circadian system and influence response to environmental signals later in life. We previously determined that a large springtime increase in solar insolation at the onset location was associated with a younger age of onset of bipolar disorder, especially with a family history of mood disorders. This study investigated whether the hours of daylight at the birth location affected this association.

METHODS

Data collected previously at 36 collection sites from 23 countries were available for 3896 patients with bipolar I disorder, born between latitudes of 1.4 N and 70.7 N, and 1.2 S and 41.3 S. Hours of daylight variables for the birth location were added to a base model to assess the relation between the age of onset and solar insolation.

RESULTS

More hours of daylight at the birth location during early life was associated with an older age of onset, suggesting reduced vulnerability to the future circadian challenge of the springtime increase in solar insolation at the onset location. Addition of the minimum of the average monthly hours of daylight during the first 3 months of life improved the base model, with a significant positive relationship to age of onset. Coefficients for all other variables remained stable, significant and consistent with the base model.

CONCLUSIONS

Light exposure during early life may have important consequences for those who are susceptible to bipolar disorder, especially at latitudes with little natural light in winter. This study indirectly supports the concept that early life exposure to light may affect the long term adaptability to respond to a circadian challenge later in life.