Psychiatric hospitalizations for affective disorders in Warsaw, Poland: Effect of season and intensity of sunlight

Effects of seasonality in emergency admissions for mental disorders: two years of clinical experience

OBJECTIVES

This retrospective study, conducted in Turin, Italy, between January 2021 and February 2023, investigates the impact of seasonal heatwaves on emergency department (ED) admissions for mental disorders.

METHODS

Through the analysis of data from 2,854 patients, this research found a significant link between the occurrence of heatwaves, especially from June to August, and an elevated rate of ED admissions for psychiatric conditions.

RESULTS

The data indicate a clear seasonal pattern, with admissions peaking during the hot months and diminishing in the colder months. Particularly, the study delineates an enhanced correlation between heatwaves and admissions for severe psychiatric disorders, such as bipolar disorder, major depression, personality disorders, and schizophrenia, accounting for 1,868 of the cases examined. This correlation was most pronounced among individuals aged 50-59 years.

CONCLUSIONS

The results of this study highlight a critical association between the incidence of seasonal heatwaves and an uptick in ED visits for psychiatric disorders, with a distinct impact on severe cases. It underscores the urgency for healthcare systems to anticipate seasonal fluctuations in psychiatric ED admissions and to allocate resources effectively to support patients during peak periods.

Seasonal patterns of sickness absence due to diagnosed mental disorders: a nationwide 12-year register linkage study

AIMS

Although seasonality has been documented for mental disorders, it is unknown whether similar patterns can be observed in employee sickness absence from work due to a wide range of mental disorders with different severity level, and to what extent the rate of change in light exposure plays a role. To address these limitations, we used daily based sickness absence records to examine seasonal patterns in employee sickness absence due to mental disorders.

METHODS

We used nationwide diagnosis-specific psychiatric sickness absence claims data from 2006 to 2017 for adult individuals aged 16-67 (n = 636,543 sickness absence episodes) in Finland, a high-latitude country with a profound variation in daylength. The smoothed time-series of the ratio of observed and expected (O/E) daily counts of episodes were estimated, adjusted for variation in all-cause sickness absence rates during the year.

RESULTS

Unipolar depressive disorders peaked in October-November and dipped in July, with similar associations in all forms of depression. Also, anxiety and non-organic sleep disorders peaked in October-November. Anxiety disorders dipped in January-February and in July-August, while non-organic sleep disorders dipped in April-August. Manic episodes reached a peak from March to July and dipped in September-November and in January-February. Seasonality was not dependent on the severity of the depressive disorder.

CONCLUSIONS

These results suggest a seasonal variation in sickness absence due to common mental disorders and bipolar disorder, with high peaks in depressive, anxiety and sleep disorders towards the end of the year and a peak in manic episodes starting in spring. Rapid changes in light exposure may contribute to sickness absence due to bipolar disorder. The findings can help clinicians and workplaces prepare for seasonal variations in healthcare needs.

A Systematic Review on the Impact of Seasonality on Severe Mental Illness Admissions: Does Seasonal Variation Affect Coercion?

Coercion in psychiatry is associated mainly with involuntary admissions. The purpose of this study was to investigate the associations between hospital admissions of patients suffering from affective and schizophrenic disorders and seasonality. A systematic literature search using PubMed, Scopus and Google Scholar was conducted, including studies with affective and schizophrenia disorder admissions, published from October 1992 to August 2020. A total of 31 studies were included in the review. Four broad severe mental illness admission categories were identified regarding seasonality: affective disorders, schizophrenia disorders, involuntary admission affective disorders and involuntary admission schizophrenia disorders. There was clear and strong evidence for spring and summer peaks for severe mental illness admissions; data provided for age, gender and involuntary admissions was limited. Seasonality may have a significant effect on the onset and exacerbation of psychopathology of severe mental illness and should be considered as a risk factor in psychiatric admissions, violence and the risk of mental health coercion. A better understanding of the impact of seasonality on severe mental illness will help professionals to provide the best practices in mental health services in order to reduce and prevent psychiatric hospitalizations (especially involuntary admissions) resulting in further coercive measures.

Seasonality of hospitalization for schizophrenia and mood disorders: A single-center cross-sectional study in China

BACKGROUND

Seasonal patterns exist in many disorders and even serve as potential drivers of some disorders, but in schizophrenia and affective disorders, there is no uniform conclusion on the seasonal pattern.

METHODS

A total of 100,621 inpatients were surveyed in this study over 16 years, and 21,668 inpatients were ultimately included in the count after standard exclusion criteria were applied.

RESULTS

There was an uneven seasonal distribution of mental illness admissions (χ2 = 48.299, df = 18, P < .001). The peak of schizophrenia admissions occurred in the winter and the trough in the spring (52.6 % vs 50 %, P < .05). The peaks for depression and bipolar disorder were in the fall and spring, respectively, while the troughs were in the winter and fall, respectively (24.7 % vs 21.7 %, P < .05; 15.2 % vs 13.2 %, P < .05). Admissions for childhood mood disorders peaked in the fall (P < .05). We also found that the length of stay was also correlated with the season of admission, and that this seasonal fluctuation was not consistent across male and female populations.

LIMITATIONS

To avoid the effect of repeated hospitalizations, we maintained a registry of each patient's first admission only, which also resulted in our inability to explore the seasonal pattern of each disease recurrence at the individual level.

CONCLUSIONS

We found that the seasonal distribution of psychiatric admissions was not uniform. And there was also an uneven seasonal distribution of length of stay for patients admitted in different seasons. This may imply that certain environmental factors that vary with the seasons are potential drivers of mental illness.

Are there joint effects of different air pollutants and meteorological factors on mental disorders? A machine learning approach

Exposure to air pollutants is considered to be associated with mental disorders (MD). Few studies have addressed joint effect of multiple air pollutants and meteorological factors on admissions of MD. We examined the association between multiple air pollutants (PM_2.5, PM₁₀, O₃, SO₂, and NO₂), meteorological factors (temperature, precipitation, relative humidity, and sunshine time), and MD risk in Yancheng, China. Associations were estimated by a generalized linear regression model (GLM) adjusting for time trend, day of the week, and patients' average age. Empirical weights of environmental exposures were judged by a weighted quantile sum (WQS) model. A machine learning approach, Bayesian kernel machine regression (BKMR), was used to assess the overall effect of mixed exposures. We calculated excess risk (ER) and 95% confidence interval (CI) for each exposure. According to the effect of temperature on MD, we divided the exposure of all factors into different temperature groups. In the high temperature group, GLM found that for every 10 μg/m³ increase in O₃, PM_2.5 and PM₁₀ exposure, the ERs were 1.926 (95%CI 0.345, 3.531), 1.038 (95%CI 0.024, 2.062), and 0.780 (95% CI 0.052, 1.512) after adjusting for covariates. Temperature, relative humidity, and sunshine time also reported significant results. The WQS identified O₃ and temperature (above the threshold) had the highest weights among air pollutants and meteorological factors. BKMR found a significant positive association between mixed exposure and MD risks. In the low temperature group, only O₃ and temperature (below the threshold) showed significant results. These findings provide policymakers and practitioners with important scientific evidence for possible interventions. The association between different exposures and MD risk warrants further study.

Exploring the association between precipitation and hospital admission for mental disorders in Switzerland between 2009 and 2019

While several studies proved the relationship between increasing temperatures and poor mental health, limited evidence exists on the effect of other weather factors, such as precipitation. This study assessed the impact of precipitation on hospital admissions for mental disorders in Switzerland between 2009-2019. We defined different precipitation events based on the duration (daily precipitation ≥1mm for 2, 3, or 4 days; PP.2/PP.3/PP.4) and intensity (≥90th percentile for 2 consecutive days; PEP90.2). First, we conducted aggregated time-stratified case-crossover analysis in eight main Swiss cities with distributed lag models to assess the association up to 3 days after the exposure. Then, we pooled the estimates in each city using a multivariate random effects meta-analysis for all hospital admissions and by subgroups (sex, age, diagnosis). Evidence of an association between precipitation and hospital admission for mental disorders was not found in Switzerland (PP.2: 1.003[0.978-1.029]; PP.3: 1.005[0.985-1.026]; PP.4: 0.994[0.960-1.030]; PEP90.2: 1.000[0.953-1.050]). Although the results were highly uncertain, we found an indication of increasing risks of hospital admission with increasing intensity of precipitation in warmer seasons (PP.2: 1.001[0.971-1.032] vs PEP90.2: 1.014[0.955-1.078]), while the risks of hospital admission slightly increased by the duration in colder season (PP.2: 1.009[0.981-1.039]; PP.3: 1.008[0.980-1.036]; PP.4: 1.017[0.956-1.081]). Overall, risks tend to be higher in people aged < 65 years. Duration of the events may influence more than intensity in females, while opposite patterns were observed in males. Risks tended to be larger but still uncertain for schizophrenia, mood disorders, and adult personality disorders. An indication of a negative association was found in neurotic disorders and null risks in the remaining groups. Although our findings did not show a clear association between precipitation and mental disorders, further research is required to clarify the role of precipitation and the potential implications of climate change and extreme precipitation events on mental health.

Seasonal Effects on Hospitalizations Due to Mood and Psychotic Disorders: A Nationwide 31-Year Register Study

Purpose

To examine seasonal patterns of hospital admissions due to mood and psychotic disorders and to investigate whether the admission rates show variation according to the seasonal daylength (photoperiods).

Patients and Methods

A retrospective nationwide register-based cohort of all psychiatric admissions (N=978,079) during 1987–2017 in Finland was utilized. The smoothed time-series of adjusted ratio of observed and expected (O/E) daily counts were estimated to examine seasonal variation. The mean O/E with 95% confidence intervals (CI) was used to study the admission rates by photoperiods. The calendar days were classified into the 71-day photoperiods based on the daylength (long/summer, short/winter, equal/spring, equal/fall) and the pace of change in daylength (slowly/rapidly increasing/decreasing daylength).

Results

Manic episodes peaked in summer during the long (mean O/E=1.10, 95% CI=1.06–1.13) and slowly decreasing (1.09, 1.06–1.13) photoperiods and had a nadir in winter during the slowly increasing (0.93, 0.89–0.98) photoperiod. Admissions for unipolar depressive (UPD) episodes peaked in autumn and in spring at the end of the rapidly decreasing (1.03, 1.02–1.04) and increasing (1.03, 1.01–1.04) photoperiod, and dropped in summer during the long and slowly decreasing (0.95, 0.94–0.96) photoperiods. Bipolar depressive (BPD) and mixed episodes signaled excess admissions in autumn and in spring. Admissions for schizophrenia were higher than expected from summer to early-autumn, during the long and slowly decreasing photoperiods (1.02, 1.02–1.03), and lower than expected in other seasons, especially in mid-spring during the rapidly increasing photoperiod (0.98, 0.98–0.99).

Conclusion

The study indicates the seasonality and photoperiodicity of mental disorders, especially for manic episodes. The seasonal pattern is similar between schizophrenia and manic episodes, and between UPD, BPD, and mixed episodes.

Recent Techniques in Determining the Effects of Climate Change on Depressive Patients: A Systematic Review

Climate change is amongst the most serious issues nowadays. Climate change has become a concern for the scientific community as it could affect human health. Researchers have found that climate change potentially impacts human mental health, especially among depressive patients. However, the relationship is still unclear and needs further investigation. The purpose of this systematic review is to systematically evaluate the evidence of the association between climate change effects on depressive patients, investigate the effects of environmental exposure related to climate change on mental health outcomes for depressive patients, analyze the current technique used to determine the relationship, and provide the guidance for future research. Articles were identified by searching specified keywords in six electronic databases (Google Scholar, PubMed, Scopus, Springer, ScienceDirect, and IEEE Digital Library) from 2012 until 2021. Initially, 1823 articles were assessed based on inclusion criteria. After being analyzed, only 15 studies fit the eligibility criteria. The result from included studies showed that there appears to be strong evidence of the association of environmental exposure related to climate change in depressive patients. Temperature and air pollution are consistently associated with increased hospital admission of depressive patients; age and gender became the most frequently considered vulnerability factors. However, the current evidence is limited, and the output finding between each study is still varied and does not achieve a reasonable and mature conclusion regarding the relationship between the variables. Therefore, more evidence is needed in this domain study. Some variables might have complex patterns, and hard to identify the relationship. Thus, technique used to analyze the relationship should be strengthened to identify the relevant relationship.

Seasonality in Major Depressive Disorder: Effect of Sex and Age

BACKGROUND

Aside from the concept of seasonal affective disorder, the evidence for a seasonal pattern (SP) of major depressive disorder (MDD) is controversial. Furthermore, the effect of sex and age is still unclear.

METHODS

This is a nationwide, registry-based study assessing all inpatient admissions in mental health hospitals due to MDD episodes according to ICD-10 (moderate (F32/33.1), severe (F32/33.2) and severe with psychotic features (F32/33.3)) in Austria across 14 years. Calculations were based on deviations from expected monthly admissions.

RESULTS

The sample comprised 231,824 hospitalisations (36.8% men) for MDD. A significant SP (p=0.001) in moderate and severe depressive episodes in both women and men with decreased admission rates in the summer months and December was detected. In psychotic depression a significant SP was only evidenced in women (p = 0.002, men: p = 0.291). Patients older than 55 years had a reduced SP compared to those being younger.

LIMITATIONS

Only anonymised admission data of inpatient treatments were available. Hospitalization rates cannot fully be equated to the occurrence of MDD.

CONCLUSIONS

The current study indicates a seasonal variation in MDD symptoms that may go beyond seasonal affective disorder. Knowledge about the predictability of depressive symptoms in patients should encourage preventive strategies.

Investigating the association between temperature and hospital admissions for major psychiatric diseases: A study in Greece

Evidence has emerged regarding the role of seasonality and several meteorological parameters on bipolar disorder, schizophrenia and depression. We investigated the relationship between ambient and apparent temperature and hospital admissions of major psychiatric diseases in a psychiatric clinic of a General Hospital situated in Northern Greece during 2013-19. Temperature data was provided by the National Observatory of Athens and diagnosis for psychotic, schizophrenic, manic and bipolar and unipolar depression were retrieved from medical records. A total of 783 admissions were recorded. Poisson regression models adjusted for time trends were applied to analyze the impact of temperature on monthly admissions. A summer peak was observed for the bipolar disorder, irrespectively of substance/alcohol use status. Seasonality emerged also for psychotic and schizophrenic patients with a through in winter. An increase of 1 °C in either ambient or apparent temperature was associated with an increase 1-2% in the monthly admissions in most outcomes under investigation. Alcohol and drug abuse did not modify this effect. Although our results indicate effects of temperature on psychiatric admissions, they are not consistent across subgroups populations and need to be replicated by other methodologically superior studies.

A Data-Driven Analysis of Sociocultural, Ecological, and Economic Correlates of Depression Across Nations

The prevalence of depression varies widely across nations, but we do not yet understand what underlies this variation. Here we use estimates from the Global Burden of Disease study to analyze the correlates of depression across 195 countries and territories. We begin by identifying potential cross-correlates of depression using past clinical and cultural psychology literature. We then take a data-driven approach to modeling which factors correlate with depression in zero-order analyses, and in a multiple regression model that controls for covariation between factors. Our findings reveal several potential correlates of depression, including cultural individualism, daylight hours, divorce rate, and GDP per capita. Cultural individualism is the only factor that remains significant across all our models, even when adjusting for spatial autocorrelation, mental healthcare workers per capita, multicollinearity, and outliers. These findings shed light on how depression varies around the world, the sociocultural and environmental factors that underlie this variation, and potential future directions for the study of culture and mental illness.

The relationship between sunlight exposure duration and depressive symptoms: A cross-sectional study on elderly Chinese women

Sunlight has been reported to have various beneficial effects on human health. Although research indicates an association between sunlight exposure and depressive symptoms, no study has examined it among the older adult population, especially among elderly Chinese women. This cross-sectional study addresses the aforesaid gap by investigating this association in 1,429 Chinese women aged 60 years and older. Information on their sunlight exposure was collected through a self-reported questionnaire. Depressive symptoms were assessed using the Zung Self-Rating Depression Scale (SDS). The logistic regression models revealed that greater exposure to sunlight is associated with a lower prevalence of depressive symptoms. In the final adjusted model, when the short sunlight exposure category (reference) was compared with the medium and long ones, the odds ratios and 95% confidence intervals for the prevalence of depressive symptoms (SDS cutoff ≥ 45) were 0.84 (0.60, 1.19) and 0.62 (0.43, 0.91), respectively (p-value for trend = 0.01). This significant association did not change when the SDS cutoff points were altered to ≥ 40 and ≥ 50. Findings indicate that an increased sunlight exposure duration is associated with a lower prevalence of depressive symptoms in elderly women.

Bimodal effects of sunlight on major depressive disorder

BACKGROUND

Seasonal patterns in the effect of sunlight on depression, where depression decreases when sunlight increases, have been observed in previous studies. In this study, we demonstrate a bimodal effect of sunlight on depression - short-term increases in sunlight increase depression and long-term increases in sunlight decrease depression. The analysis showed that the significant effect of sunlight is temporary and appears only when seasonal changes are severe within a given year.

METHODS

We analyzed approximately 530,000 cases where patients visited hospital for depression in Korea from January 1 to December 31, 2016. We measured the daily average amount of sunlight and daily sunlight for the 30 days previous to the day of measurement using data from 96 weather stations. To analyze the effect of sunlight, several climatic variables and local dummies were added to the negative binomial model, and the period in which the effect of sunlight was significant was derived as a term of the interaction between the month variable and sunlight.

RESULTS

When the average effects of climatic factors such as temperature, precipitation, and humidity were removed, the number of cases of depression increased when the daily average amount of sunlight increased [IRR = 1.024 (95% CI: 1.009 to 1.039)]; this effect was significant only in January and May. The number of cases of depression decreased with higher daily average sunlight for the previous 30 days increasing [IRR = 0.917 (95% CI: 0.892 to 0.944)], and this effect was significant only in January, March, and May.

CONCLUSIONS

The effect of sunlight on depression appears in both the short and long terms, but the effect is significant only for limited periods. The data examined in this study supports a pattern where short-term daily sunlight increases depression and daily sunlight for the previous 30 days decreases depression.

The Meaning of Recovery: The Lived Experience of Patients with Bipolar Disorder in Turkey

Recovery in mental illness refers to a process with many aspects, steps and meanings. This study aims to provide a deeper understanding of the lived experience of recovery of patients with bipolar disorder. A qualitative approach with 28 participants was performed. Data were collected through semi-structured interviews. The experiences of the individuals regarding the recovery processes were themed with the journey metaphor: the beginning of the journey, the route of the journey, a stop in the journey, the meaning of the journey. This study suggests ways clinicians must be aware of and adopted contemporary approach which recovery is defined as a process beyond treatment.

A new approach for seasonal pattern: is it related to bipolarity dimension? Findings from an Italian multicenter study

OBJECTIVE

The aims of this study were to assess the impact of seasonal pattern on several clinical dimensions in inpatients with a current major depressive episode and to evaluate clinical differences between unipolar and bipolar depression according to seasonal pattern.

METHODS

Study participants were 300 patients affected by major depressive disorder (MDD) or bipolar disorder (BD) currently experiencing a major depressive episode (MDE) and were recruited at three University Medical Centres in Italy. All study subjects completed several evaluation scales for depressive and hypomanic symptoms, quality of life and functioning, impulsiveness, and seasonal pattern.

RESULTS

Several differences between BD with and without seasonal pattern, MDD with and without seasonal pattern but in particular between BD and MDD with seasonal pattern were found. Patients with MDE with seasonal pattern had more frequently received a longitudinal diagnosis of BD.

CONCLUSIONS

A large number of patients with BD and seasonal pattern, but also a considerable number of patients with MDD and seasonal pattern, endorsed manic items during a current MDE. Seasonal pattern should be associated with a concept of bipolarity in mood disorders and not only related to bipolar disorder. A correct identification of seasonal patterns may lead to the implementation of personalised pharmacological treatment approaches.KEY POINTSHigh prevalence of mixed features in mood disorders with seasonal pattern, supporting the need for a dimensional approach to major depressive disorder and bipolar disorder.Significant percentage of patients with a primary diagnosis of major depressive disorder had seasonal pattern.Significant percentage of patients with a primary diagnosis of major depressive disorder reported (hypo)manic symptomatology.

Weather and Aggressive Behavior among Patients in Psychiatric Hospitals-An Exploratory Study

Background: The number of meteoropaths, or people negatively affected by weather conditions, is rising dramatically. Meteoropathy is developing rapidly due to ever poorer adaptations of people to changes in weather conditions. Strong weather stimuli may not only exacerbate symptoms in people with diseases of the cardiovascular and respiratory systems but may also induce aggressive behavior. Researchers have shown that patients suffering from mental illnesses are most vulnerable to changes in the weather and postulate a connection between the seasons and aggressive behavior. Methods: The goal of the study was to analyze the relationship between coercive measures and weather factors. The researchers identified what meteorological conditions prevailed on days with an increased number of incidents of aggressive behavior leading to the use of physical coercion towards patients in a psychiatric hospital in Poland. In order to determine the impact of weather conditions on the frequency at which physical coercion measures were used, the hospital’s “coercion sheets” from 1 January 2015 to 31 March 2017 were analyzed. The data were correlated with meteorological data. In order to determine the relationship between the occurrence of specific weather conditions and the number of coercive interventions (N), researchers utilized Spearman’s rank correlation analysis together with two-dimensional scatter diagrams (dependency models), multiple regression, stepwise regression, frequencies, and conditional probability (%). Results: Lower barometric pressure and foehn wind increased aggressive behavior in patients that led to coercive measures. For temperature (positive correlation) and humidity (negative correlation), there was a poor but statistically significant correlation. Conclusions: Monitoring weather conditions might be useful in predicting and preventing aggression by patients who are susceptible to weather changes

The effect of air-pollution and weather exposure on mortality and hospital admission and implications for further research: A systematic scoping review

BACKGROUND

Air-pollution and weather exposure beyond certain thresholds have serious effects on public health. Yet, there is lack of information on wider aspects including the role of some effect modifiers and the interaction between air-pollution and weather. This article aims at a comprehensive review and narrative summary of literature on the association of air-pollution and weather with mortality and hospital admissions; and to highlight literature gaps that require further research.

METHODS

We conducted a scoping literature review. The search on two databases (PubMed and Web-of-Science) from 2012 to 2020 using three conceptual categories of "environmental factors", "health outcomes", and "Geographical region" revealed a total of 951 records. The narrative synthesis included all original studies with time-series, cohort, or case cross-over design; with ambient air-pollution and/or weather exposure; and mortality and/or hospital admission outcomes.

RESULTS

The final review included 112 articles from which 70 involved mortality, 30 hospital admission, and 12 studies included both outcomes. Air-pollution was shown to act consistently as risk factor for all-causes, cardiovascular, respiratory, cerebrovascular and cancer mortality and hospital admissions. Hot and cold temperature was a risk factor for wide range of cardiovascular, respiratory, and psychiatric illness; yet, in few studies, the increase in temperature reduced the risk of hospital admissions for pulmonary embolism, angina pectoris, chest, and ischemic heart diseases. The role of effect modification in the included studies was investigated in terms of gender, age, and season but not in terms of ethnicity.

CONCLUSION

Air-pollution and weather exposure beyond certain thresholds affect human health negatively. Effect modification of important socio-demographics such as ethnicity and the interaction between air-pollution and weather is often missed in the literature. Our findings highlight the need of further research in the area of health behaviour and mortality in relation to air-pollution and weather, to guide effective environmental health precautionary measures planning.

What is the role of meteorological variables on involuntary admission in psychiatric ward? An Italian cross-sectional study

Weather affects physical and mental health through several modalities which are not fully elucidated. The aim of the present study was to investigate the impact of meteorological variables and other indexes in a large sample of hospitalized patients, focusing on subjects who were involuntarily admitted. We hypothesized a direct relation between the amount of involuntary admissions and mean sunshine hours. Furthermore, we supposed that specific meteorological factors may significantly influence hospitalizations of patients affected by severe psychiatric conditions. All subjects were consecutively recruited from the Psychiatric Inpatient Unit of San Luigi Gonzaga Hospital, Orbassano (Turin, Italy) from September 2013 to August 2015. Socio-demographic and clinical characteristics were carefully collected. Meteorological data were derived by the Italian Meteorology's Climate Data Service of Physics Department of the University of Turin (Latitude: 45°03'07,15″ Nord, Longitude: 007°40'53,30″ Est, Altitude: 254 m above the sea level) (http://www.meteo.dfg.unito.it/). Our data indicate significant differences regarding temperature (minimum, maximum, and medium), solar radiation, humidex and windchill index, and hours of sunshine in psychiatric patients who were involuntarily hospitalized. After logistic regression analyses, only maximum and medium temperature, and humidex index remained significantly associated with involuntary admission in an emergency psychiatric ward. The limitations of this study include the cross-sectional study design and the single hospital for patients' recruitment. Furthermore, results and seasonal patterns obtained by patients requiring hospitalization might significantly differ from those who were not hospitalized. Exploring in a more detailed manner those environmental factors associated with involuntary admissions could lead to early intervention and prevention strategies for such distressing hospitalizations.

Natural sunlight plus vitamin D supplementation ameliorate delayed early motor development in newborn infants from maternal perinatal depression

BACKGROUND

Increased cortisol has been shown to be negatively correlated with infant motor development. Sunlight help decrease the level of cortisol. Vitamin D is associated with infant motor development. The present study aimed to determine whether natural sunlight exposure plus vitamin D supplements could ameliorate delayed early motor development in little infants from maternal perinatal depression.

METHODS

The term pregnant women waiting for delivery from the department of gynecology and obstetrics were assessed depressive symptoms by Hamilton Rating Scale for Depression (HAMD). 120 normal and 229 depressed subjects were recruited. During 2 days postpartum, infant motor development were assessed by Neonatal Behavioral Assessment Scale (NBAS). Infants of 2-day-old in maternal depression group were divided into four groups: control group, conventional vitamin D supplements (400IU/d) group, high dose of vitamin D supplements group (1000IU/d), sunlight plus conventional vitamin D supplement group (400IU/d). Serum and hair cortisol (HairF) in mothers and infants were measured.

RESULTS

The infants of perinatal depressed mothers displayed early motor developmental delay accompanied by increased cortisol. Sunlight plus conventional vitamin D supplement (400IU/d) were better than exclusive vitamin D supplements for the amelioration delayed early motor development in infants (p < 0.05). The infants exposure to sunlight 7-14 h/week plus conventional vitamin D supplement reached the best scores of motor development and the lowest HairF (p < 0.05).

LIMITATIONS

We should have measured the serum 25OH-vitamin D concentrations.

CONCLUSIONS

Sunlight plus vitamin D supplements could ameliorate delayed early motor development in little infants by decreasing cortisol from perinatal depression.

Chris Cornell, the Black Hole Sun, and the Seasonality of Suicide

PURPOSE

Seattle-inspired rock and roll superstar Chris Cornell died by suicide in May 2017. In the northern hemisphere, May represents the peak of the widely replicated but still unexplained seasonal spring rhythm in suicide. Years earlier, Cornell had suffered openly from recurrent bouts of severe depression, and his early musical lyrics do indeed suggest an enduring sensitivity to the vicissitudes of depressed and suicidal states. Cornell's most famous song, Black Hole Sun, suggests a mixed mood state, the incidence of which also peaks in the spring. The present work explores Cornell's May suicide from a chronobiologic perspective.

METHODS

Review of Cornell's lyrics and literature on suicide.

RESULTS

Cornell's lyrics contain clear indicators of mixed depressive and seasonal imagery, highlighting 3 fundamental axioms of suicidology: (1) the yearly suicide rhythm peaks in May in the northern hemisphere, (2) mixed depressive states are particularly lethal, and (3) the suicide risk increases dramatically when recovering from depression and mood turns mixed.

CONCLUSIONS

Cornell, in his life and music, left us with a novel and important hypothesis about the spring seasonality of suicide, namely, that the yearly suicide risk becomes maximal when winter turns to spring and there emerges a deadly mixed mood state under a May photoperiod, i.e., the suicide risk is maximal when a Black Hole Sun occurs in May. It is hoped that Cornell's legacy and sensitive hypothesis inspire research into the etiology and treatment of the spring seasonality of suicide risk and mixed mood states.

LIMITATIONS

The Cornell hypothesis was formulated based in part on several speculative inferences regarding the course of his functioning just prior to his suicide.

Seasonality and symptoms of depression: A systematic review of the literature

AIMS

Lay opinions and published papers alike suggest mood varies with the seasons, commonly framed as higher rates of depression mood in winter. Memory and confirmation bias may have influenced previous studies. We therefore systematically searched for and reviewed studies on the topic, but excluded study designs where explicit referrals to seasonality were included in questions, interviews or data collection.

METHODS

Systematic literature search in Cochrane database, DARE, Medline, Embase, PsychINFO and CINAHL, reporting according to the PRISMA framework, and study quality assessment using the Newcastle-Ottawa scale. Two authors independently assessed each study for inclusion and quality assessment. Due to large heterogeneity, we used a descriptive review of the studies.

RESULTS

Among the 41 included studies, there was great heterogeneity in regards to included symptoms and disorder definitions, operationalisation and measurement. We also observed important heterogeneity in how definitions of 'seasons' as well as study design, reporting and quality. This heterogeneity precluded meta-analysis and publication bias analysis. Thirteen of the studies suggested more depression in winter. The remaining studies suggested no seasonal pattern, seasonality outside winter, or inconclusive results.

CONCLUSIONS

The results of this review suggest that the research field of seasonal variations in mood disorders is fragmented, and important questions remain unanswered. There is some support for seasonal variation in clinical depression, but our results contest a general population shift towards lower mood and more sub-threshold symptoms at regular intervals throughout the year. We suggest future research on this issue should be aware of potential bias by design and take into account other biological and behavioural seasonal changes that may nullify or exacerbate any impact on mood.

Exposure-lag-response association between sunlight and schizophrenia in Ningbo, China

Previous studies found that mental disorders such as bipolar disorder, seasonal affective disorder and schizophrenia, often show seasonal variability, which usually be attributed to the variations in the number of natural sunlight. However, few studies have been conducted on the acute effects of exposure to sunlight on the onset of these disease. The aim of this study was to evaluate the exposure-response relationship between sunshine duration and the hospital admissions for schizophrenia. We obtained data on hospital admissions for schizophrenia from the largest psychiatric hospital in Ningbo, China, during 2012-2016. A Distributed lag non-linear model was used to estimate the exposure-lag-response relationship between sunlight and schizophrenia. We calculated the effects of short and long sunshine duration, defined using the cutoffs at the 1st and 99th sunshine duration percentiles. We detected significant and non-linear associations between sunlight and schizophrenia, and the overall estimated relative risk (RR) for a lag of 0-21 days was 1.45 (95% CI: 1.07, 1.97) and 1.41(95% CI: 0.72, 2.75) for short and long sunshine duration, respectively. The burden of schizophrenia was greater during periods with short sunshine duration than during periods with long sunshine duration, with the AFs of 19.94% (95% CI: 8.65%, 28.24%) and 2.12% (95% CI: -2.70%, 5.57%), respectively. The female and people more than 45 years old were most susceptible to these effects. We repeated our analysis by using global solar radiation as a continuous exposure variable of sunlight intensity in the model, and the result shows that the female and middle-aged and eldly patients were also susceptible to the effects of low levels of global solar radiation. Our findings suggest that there may be a relationship between lack of exposure to sunlight and increased risk of hospital admissions for schizophrenia. Policymakers and doctors should promote further understanding of the health benefits of sunlight and take effective measures to prevent schizophrenia.

Short-term PM2.5 exposure and emergency hospital admissions for mental disease

Epidemiologic studies regarding the relationship between short-term exposure to particulate matter with a median aerodynamic diameter < 2.5 µm (PM_2.5) and mental disease are limited. This study examined the effects of short-term exposure to PM_2.5 on emergency admissions to the hospital for mental disease in Seoul, Korea. Data regarding 80,634 emergency admissions for mental diseases were collected from a nationally centralized healthcare claims database in Seoul during 2003-2013. Generalized linear models with climate variables were used to examine associations between short-term PM_2.5 exposure and mental disease admissions. To comprehensively assess PM_2.5 effects, we used single- and two-pollutant models, which considered other pollutants in combination with PM_2.5. The relative risk (RR) of emergency admissions for mental disease was 1.008 (95% confidence interval, 1.001-1.015) for each 10 μg/m³ increase in 2-day average PM_2.5 concentration. This effect persisted or became slightly stronger in the two-pollutant models that included carbon monoxide, nitrogen dioxide, ozone, or sulfur dioxide (RR, 1.01-1.021), but association appeared to be limited to individuals < 65 years of age. Significant association was estimated only during the warm season (RR, 1.021-1.023) in the two-pollutant models. The exposure-response curve was steeper at lower concentrations, suggesting that the risk of mental disease at lower concentrations of pm2.5 (0-30 µg/m³). PM_2.5 was associated with increased admissions even when it was below the World Health Organization's Air Quality Guidelines (25 μg/m³), but the association was not statistically significant. Thus, based on the data from a large database, exposure to PM_2.5 was associated with increases in emergency admissions for mental diseases, and this association was significant during the warm season. PM_2.5 may even affect mental disease at levels below the current air quality guidelines. These results provide substantial insight regarding the effects of air pollutants and have important implications for policy makers.

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.

Ambient temperature, sunlight duration, and suicide: A systematic review and meta-analysis

BACKGROUND

The relationship between sunlight hours, temperature, and suicide has been investigated in many previous studies, but with inconsistent findings. We conducted this meta-analysis aiming at providing clear evidence about whether sunlight hours and temperature can affect the risk of suicide.

METHODS

Relevant literature published before 7 Jul 2018 was searched in three electronic database of PubMed, Web of science and Cochrane. Between-study heterogeneity in the effect estimates were examined by study design (i.e., exposure time resolution, temperature measure and suicide classification) and population vulnerability (i.e., sex, national income level, climate zone and study location).

RESULTS

Regarding temperature-suicide association, we identified 14 studies that provided 23 effect estimates for meta-analysis. Our random-effects model showed that each 1 °C increase in temperature was significantly associated with a 1% increase in the incidence of suicide (Incidence Rate Radio (IRR) = 1.01; 95%CI = 1.00-1.02; p < 0.05). As for sunlight duration and suicide, 11 effect estimates from 4 studies were pooled using a fixed-effects model. Significant association between sunlight duration (per 1 h increase) and the risk of suicide was not observed, and the pooled IRR was 1.00 (95%CI = 0.99-1.01; p > 0.05). There was significant heterogeneity between previous studies' effect estimates, and significantly lower heterogeneity was noted for the female group, for studies that did analyses at daily scale, and for studies using mean temperature as the exposure indicator.

CONCLUSION

Our findings suggest a significant and positive association between temperature rises and incidence of suicide, and a non-significant association between sunlight duration and incidence of suicide. Populations living in tropical and temperate zones or at middle-income level may be particularly vulnerable to temperature increase.

Investigating the effect of climatic parameters on mental disorder admissions

The main objective of this study was to evaluate the role of climatic parameters and phenomena including the monthly number of dusty/rainy/snowy/foggy days, cloudiness (Okta), horizontal visibility, and barometric pressure (millibar) on major depressive disorder, bipolar, schizophrenia, and schizoaffective admissions. The monthly data related to the number of admissions in Farshchian hospital and climatic parameters from March 2005 to March 2017 were extracted. Random forest regression and dynamic negative binomial regression were used to examine the relationship between variables; the statistical significance was considered as 0.05. The number of dusty/rainy/snowy/foggy days, cloudiness, and the number of days with vision less than 2 km had a significant positive relationship with admissions due to schizophrenia (p < 0.05). Barometric pressure had a negative effect on schizophrenia admissions (p < 0.001). The number of dusty/rainy/snowy/foggy days and cloudiness had a significant effect on schizoaffective admissions (p < 0.05). Bipolar admissions were negatively associated with rainy days and positively associated with dusty days and cloudiness (p < 0.05). The number of rainy/dusty/snowy days and cloudiness had a positive significant effect on major depressive disorder admissions. The results of the present study confirmed the importance of climatic parameter variability for major depressive disorder, bipolar, schizophrenia, and schizoaffective admissions.

Seasonal variation of spontaneous blink rate and beta EEG activity

Seasonal variations of the photoperiod have been shown to regulate biological and behavioral functions, with also effects on clinical symptom and course of several psychiatric conditions. Although melatonin is considered the principal signal used to transmit informations about the light and dark cycle, a dopamine (DA) role in regulating seasonal changes has been suggested. Few studies have addressed a seasonal pattern of dopamine, and human studies have been conducted on inter-subject differences, comparing measures obtained during fall-winter with those of spring-summer. We studied within-subject seasonal changes of blink rate (BR), a indirect marker of central DA activity, in 26 normal subjects (15 females and 11 males, mean age: 24.7 ± 4.0) during winter, spring, summer and fall. Occipital EEG activity and subjective measures of vigilance and mood were also assessed to account for variations on arousal and fatigue. A significant seasonal effect was found for BR, with higher rate in summer, and for EEG beta activity, with higher activity in spring and summer. Subjective fatigue was found higher in winter. According to our data, it is possible that higher BR and increased EEG beta activity result by an arousal activation sustained by dopamine systems during the months with a long photoperiod.

Moderate UV Exposure Enhances Learning and Memory by Promoting a Novel Glutamate Biosynthetic Pathway in the Brain

Sunlight exposure is known to affect mood, learning, and cognition. However, the molecular and cellular mechanisms remain elusive. Here, we show that moderate UV exposure elevated blood urocanic acid (UCA), which then crossed the blood-brain barrier. Single-cell mass spectrometry and isotopic labeling revealed a novel intra-neuronal metabolic pathway converting UCA to glutamate (GLU) after UV exposure. This UV-triggered GLU synthesis promoted its packaging into synaptic vesicles and its release at glutamatergic terminals in the motor cortex and hippocampus. Related behaviors, like rotarod learning and object recognition memory, were enhanced after UV exposure. All UV-induced metabolic, electrophysiological, and behavioral effects could be reproduced by the intravenous injection of UCA and diminished by the application of inhibitor or short hairpin RNA (shRNA) against urocanase, an enzyme critical for the conversion of UCA to GLU. These findings reveal a new GLU biosynthetic pathway, which could contribute to some of the sunlight-induced neurobehavioral changes.

Weather conditions influence the number of psychiatric emergency room patients

The specific impact of weather factors on psychiatric disorders has been investigated only in few studies with inconsistent results. We hypothesized that meteorological conditions influence the number of cases presenting in a psychiatric emergency room as a measure of mental health conditions. We analyzed the number of patients consulting the emergency room (ER) of a psychiatric hospital in Berlin, Germany, between January 1, 2008, and December 31, 2014. A total of N = 22,672 cases were treated in the ER over the study period. Meteorological data were obtained from a publicly available data base. Due to collinearity among the meteorological variables, we performed a principal component (PC) analysis. Association of PCs with the daily number of patients was analyzed with autoregressive integrated moving average model. Delayed effects were investigated using Granger causal modeling. Daily number of patients in the ER was significantly higher in spring and summer compared to fall and winter (p < 0.001). Three PCs explained 76.8% percent of the variance with PC1 loading mostly on temperature, PC2 on cloudiness and low pressure, and PC3 on windiness. PC1 and PC2 showed strong association with number of patients in the emergency room (p < 0.010) indicating higher patient numbers on warmer and on cloudy days. Further, PC1, PC2, and PC3 predicted the number of patients presenting in the emergency room for up to 7 days (p < 0.050). A secondary analysis revealed that the effect of temperature on number of patients was mostly due to lower patient numbers on cold days. Although replication of our findings is required, our results suggest that weather influences the number of psychiatric patients consulting the emergency room. In particular, our data indicate lower patient numbers during very cold temperatures.

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.

Environmental factors, life events, and trauma in the course of bipolar disorder

The etiology and clinical course of bipolar disorder are considered to be determined by genetic and environmental factors. Although the kindling hypothesis emphasizes the impact of environmental factors on initial onset, their connection to the outcome and clinical course have been poorly established. Hence, there have been numerous research efforts to investigate the impact of environmental factors on the clinical course of illness. Our aim is to outline recent research on the impact of environmental determinants on the clinical course of bipolar disorder. We carried out a computer-aided search to find publications on an association between environmental factors, life events, and the clinical course of bipolar disorder. Publications in the reference lists of suitable papers have also been taken into consideration. We performed a narrative overview on all eligible publications. The available body of data supports an association between environmental factors and the clinical course of bipolar disorder. These factors comprise prenatal, early-life, and entire lifespan aspects. Given varying sample sizes and several methodological limitations, the reported quality and extent of the association between environmental factors and the clinical course of bipolar disorder should be interpreted with utmost caution. Systematic longitudinal long-term follow-up trials are needed to obtain a clearer and more robust picture.

Seasonal variations in hospital admissions for mania: Examining for associations with weather variables over time

BACKGROUND

Bipolar disorder is characterized by a seasonal pattern with emerging evidence that weather conditions may trigger symptoms. Thus, our aims were to investigate if year-to-year variations in admissions with mania correlated with year-to-year variations in key meteorological variables, if there was a secular trend in light of climate change and if gender or admission status influenced the seasonal pattern.

METHODS

We undertook a Danish register-based nationwide historical cohort study. We included all adults hospitalized to psychiatric care from 1995 to 2012 with mania using the Danish Psychiatric Central Research Register. The Danish Meteorological Institute provided the meteorological variables. The association between weather and admissions was tested using linear regression.

RESULTS

Our database comprised 24,313 admissions with mania. There was a seasonal pattern with admission rates peaking in summer. Higher admission rates were associated with more sunshine, more ultraviolet radiation, higher temperature and less snow but were unassociated with rainfall. We did not find a secular trend in the seasonal pattern. Finally, neither gender nor admission status impacted on the overall seasonal pattern of admissions with mania.

LIMITATIONS

Only patients in psychiatric care were included. We could not subdivide by type of bipolar disorder.

CONCLUSION

This cohort study based on more than 24,000 admissions identified a distinct seasonal pattern in hospital admissions for those with mania. We found no secular trend. This could indicate that the climate change is not impacting on seasonal patterns, that there is no link between the proposed variables or that change is currently not sufficiently distinctive.

Involuntary admissions in Italy: the impact of seasonality

OBJECTIVE

The aim of this study is to assess the prevalence of involuntary admissions with regard to seasonality and clinical associated features, in a sample of patients admitted to a psychiatric unit in a period of 24 months.

METHODS

All subjects consecutively admitted to the Psychiatric Inpatient Unit of the San Luigi Gonzaga Hospital, Orbassano (University of Turin, Italy) from September 2013 to August 2015 were recruited. Socio-demographic and clinical characteristics were collected.

RESULTS

Seven hundred and thirty admissions in psychiatric ward were recognized. The prevalence of involuntary admission was 15.4%. Patients with involuntary hospitalizations showed a higher education level, a higher prevalence of admission in spring/summer with a significant peak in June, a longer duration of hospitalization and a lower suicide ideation. Among involuntary admissions, physical restraint and suicide attempts were more prevalent during spring compared to the other seasons.

CONCLUSIONS

Seasonality has an important role in the psychopathology of psychiatric disorders, particularly in bipolar and related disorder, and may represent an influencing factor in hospital admissions and hospitalizations. Seasonal pattern must be considered while managing diagnosis and treatment of mental disorders, with regard to prevention and psychoeducation of patients.