Seasonality in depressive and anxiety symptoms among primary care patients and in patients with depressive and anxiety disorders; results from the Netherlands Study of Depression and Anxiety

Mental health trajectories among the general population and higher-risk groups following the COVID-19 pandemic in Switzerland, 2021-2023

BACKGROUND

Mental health deteriorated in the early stages of the COVID-19 pandemic, but improved relatively quickly as restrictions were eased, suggesting overall resilience. However, longer-term follow-up of mental health in the general population is scarce.

METHODS

We examined mental health trajectories in 5624 adults (58 % women; aged 18-97 years) from the Specchio-COVID19 cohort, using the Generalized Anxiety Disorder scale-2 and the Patient Health Questionnaire-2, administered each month from February to June 2021, and in Spring 2022 and 2023.

RESULTS

Depressive and anxiety symptoms declined during a pandemic wave from February to May 2021 (β = -0.06 [-0.07, -0.06]; -0.06 [-0.07, -0.05]), and remained lower at longer-term follow-up than at the start of the wave. Loneliness also declined over time, with the greatest decline during the pandemic wave (β = -0.25 [-0.26, -0.24]). Many higher-risk groups, including socioeconomically disadvantaged individuals, those with a chronic condition, and those living alone had poorer mental health levels throughout the study period. Women and younger individuals had a faster improvement in mental health during the pandemic wave. Loneliness trajectories were associated with mental health trajectories throughout the study period.

LIMITATIONS

We cannot definitively conclude that the observed changes in mental health were due to experiences of the pandemic.

CONCLUSIONS

While there was a need for additional mental health support during stricter policy responses to COVID-19, overall, mental health improved relatively soon after measures were eased. Nevertheless, the persistence of mental health disparities highlights the need for further efforts from the government and healthcare practitioners to support vulnerable groups beyond the pandemic.

Prevalence and Associations of Depression among Saudi College Nursing Students: A Cross-Sectional Study

Depression affects approximately 350 million individuals globally and is the leading cause of disability. Depression among nursing students is an ongoing issue, yet little is known about the relationship between depression and its risk factors among nursing students in Saudi Arabia. The purpose of this study was to determine the prevalence of depression among a cohort of Saudi nursing students and to explore the risk factors associated with depression in this group. A cross-sectional design was employed for this study, which was conducted by the nursing faculty at King Saud University in Riyadh, Saudi Arabia. The researcher sampled 330 nursing students, with 252 students (a 76.3% response rate) randomly selected by the academic advising unit in the nursing college between January and February 2023. The participants completed an online survey based on the Arabic version of the Center for Epidemiologic Studies Depression Scale. The data were analyzed using univariate analysis and backward multi-variable logistic regression. The findings revealed that 65.1% of the participants scored 16 or above on the depression scale, indicating high levels of depressive symptoms. Univariate analysis identified several significant risk factors for depression, including sex (OR, 0.29; 95% CI, 0.16-0.51; p < 0.001), academic pressure (OR, 5.87; 95% CI, 2.04-16.84; p < 0.001), interpersonal relationships (evaluated by balance and harmony in thoughts, emotions, behavior, and interactions with others; categorized as good/fair or poor), and the relationship with the father, which were strongly associated with the presence of depression symptoms. Backward multi-variable logistic regression analysis further revealed that being male, experiencing reduced academic pressure, having stronger father-son relationships, and maintaining positive interpersonal relationships were significantly associated with decreased levels of depression (ORs ranged from 0.25 to 3.94). These findings highlight the need for family and school-based prevention interventions to help nursing students in college avoid depression.

Anxiety among healthcare workers during the COVID-19 pandemic: a longitudinal study

Background

During the COVID-19 pandemic, many healthcare workers faced extreme working conditions and were at higher risk of infection with the coronavirus. These circumstances may have led to mental health problems, such as anxiety, among healthcare workers. Most studies that examined anxiety among healthcare workers during the COVID-19 pandemic were cross-sectional and focused on the first months of the pandemic only. Therefore, this study aimed to investigate the longitudinal association between working in healthcare and anxiety during a long-term period (i.e., 18 months) of the COVID-19 pandemic.

Methods

Data were used from online questionnaires of the Lifelines COVID-19 prospective cohort with 22 included time-points (March 2020-November 2021). In total, 2,750 healthcare workers and 9,335 non-healthcare workers were included. Anxiety was assessed with questions from the Mini-International Neuropsychiatric Interview, and an anxiety sum score (0-7) was calculated. Negative binomial generalized estimating equations (GEE), adjusted for demographic, work and health covariates, were used to examine the association between working in healthcare and anxiety.

Results

Anxiety sum scores over time during the COVID-19 pandemic were similar for healthcare workers and non-healthcare workers. No differences between the anxiety sum scores of healthcare workers and non-healthcare workers were found [incidence rate ratio (IRR) = 0.97, 95% CI = 0.91-1.04].

Conclusion

This study did not find differences between healthcare workers and non-healthcare in perceived anxiety during the COVID-19 pandemic.

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.

Prevalence and predictors of psychological distress before, during, and after a COVID-19 pandemic wave in Switzerland, 2021

There are concerns about acute and long-term mental health effects of the COVID-19 pandemic. This study examined the prevalence and predictors of psychological distress before, during, and after a pandemic wave in Switzerland, 2021. Prevalence of psychological distress was estimated in adults aged 35-96 years using the General Health Questionnaire-12 administered in June 2021 (Specchio-COVID19 cohort, N = 3965), and compared to values from 2003 to 2006 (CoLaus|PsyCoLaus cohort, N = 5667). Anxiety and depression were assessed from February to June 2021 using the Generalised Anxiety Disorder scale-2 and the Patient Health Questionnaire-2, respectively. Prevalence of psychological distress in June 2021, after the pandemic wave (16.0% [95% CI, 14.6%-17.4%]) was comparable to pre-pandemic levels (15.1% [14.0%-16.2%]). Anxiety and depression were highest at the start of the pandemic wave in February 2021, and declined from February to June with the relaxation of measures. Predictors of psychological distress included being younger, female, a single parent, unemployed, a change in working hours or job loss in the past 6 months, greater perceived severity and contagiousness of COVID-19, and self-reported post COVID-19. By June 2021, following a pandemic wave, prevalence of psychological distress in Switzerland was closer to pre-pandemic levels. These findings highlight the need for additional mental health support during times of stricter government policies relating to COVID-19; yet they also suggest that individuals can adapt relatively quickly to the changing context.

Relationship between Depressive Symptoms and Weather Conditions

Background: Weather is a well-known factor worldwide in psychiatric problems such as depression, with the elderly and females being particularly susceptible. The aim of this study was to detect associations between the risk of depressive symptoms (DS) and weather variables. Methods: 6937 participants were assessed in the baseline survey of the Health Alcohol Psychosocial Factors in Eastern Europe (HAPIEE) study during 2006−2008. To assess the risk of DS, a multivariate logistic model was created with predictors such as socio-demographic factors, health behaviors, and weather variables. Results: DS were found in 23.4% of the respondents, in 15.6% of males and in 29.9% in females. A higher risk of DS (by 25%) was associated with November−December, a rising wind speed, and relative humidity (RH) < 94% and snowfall during the cold period occurring 2 days before the survey. A higher air temperature (>14.2 °C) predominant during May−September had a protective impact. A higher risk of DS in males was associated with lower atmospheric pressure (<1009 hPa) 2 days before. Females were more sensitive to the monthly variation, snowfall, and RH. Conclusions: The findings of our study suggest that some levels of weather variables have a statistically significant effect on DS.

EEG-responses to mood induction interact with seasonality and age

The EEG is suggested as a potential diagnostic and prognostic biomarker for seasonal affective disorder (SAD). As a pre-clinical form of SAD, seasonality is operationalized as seasonal variation in mood, appetite, weight, sleep, energy, and socializing. Importantly, both EEG biomarkers and seasonality interact with age. Inducing sad mood to assess cognitive vulnerability was suggested to improve the predictive value of summer assessments for winter depression. However, no EEG studies have been conducted on induced sad mood in relation to seasonality, and no studies so far have controlled for age. We recorded EEG and calculated bandpower in 114 participants during rest and during induced sad mood in summer. Participants were grouped by age and based on a seasonality score as obtained with the seasonal pattern assessment questionnaire (SPAQ). Participants with high seasonality scores showed significantly larger changes in EEG power from rest to sad mood induction, specifically in the alpha frequency range (p = 0.027), compared to participants with low seasonality scores. Furthermore, seasonality interacted significantly with age (p < 0.001), with lower activity in individuals with high seasonality scores that were older than 50 years but the opposite pattern in individuals up to 50 years. Effects of sad mood induction on brain activity are related to seasonality and can therefore be consider as potential predicting biomarkers for SAD. Future studies should control for age as a confounding factor, and more studies are needed to elaborate on the characteristics of EEG biomarkers in participants above 50 years.

Do psychiatric diseases follow annual cyclic seasonality?

Seasonal affective disorder (SAD) famously follows annual cycles, with incidence elevation in the fall and spring. Should some version of cyclic annual pattern be expected from other psychiatric disorders? Would annual cycles be similar for distinct psychiatric conditions? This study probes these questions using 2 very large datasets describing the health histories of 150 million unique U.S. citizens and the entire Swedish population. We performed 2 types of analysis, using “uncorrected” and “corrected” observations. The former analysis focused on counts of daily patient visits associated with each disease. The latter analysis instead looked at the proportion of disease-specific visits within the total volume of visits for a time interval. In the uncorrected analysis, we found that psychiatric disorders’ annual patterns were remarkably similar across the studied diseases in both countries, with the magnitude of annual variation significantly higher in Sweden than in the United States for psychiatric, but not infectious diseases. In the corrected analysis, only 1 group of patients—11 to 20 years old—reproduced all regularities we observed for psychiatric disorders in the uncorrected analysis; the annual healthcare-seeking visit patterns associated with other age-groups changed drastically. Analogous analyses over infectious diseases were less divergent over these 2 types of computation. Comparing these 2 sets of results in the context of published psychiatric disorder seasonality studies, we tend to believe that our uncorrected results are more likely to capture the real trends, while the corrected results perhaps reflect mostly artifacts determined by dominantly fluctuating, health-seeking visits across a given year. However, the divergent results are ultimately inconclusive; thus, we present both sets of results unredacted, and, in the spirit of full disclosure, leave the verdict to the reader.

Should we expect psychiatric disorders to show a cyclic annual pattern? This study reveals that psychiatric diseases’ annual patterns were remarkably similar across the studied diseases in both the US and Sweden, with the magnitude of annual variation significantly higher in Sweden than in the US for psychiatric, but not infectious, diseases.

Colorectal Cancer Care and Patients' Perceptions Before and During COVID-19: Implications for Subsequent SARS-CoV-2 Infection Waves

Background

Changes in colorectal cancer (CRC) care planning because of the coronavirus disease 2019 (COVID-19) pandemic and associated health-related quality of life (HRQoL) and well-being of patients with CRC are unknown. We report changes in CRC care and patient-reported outcomes including HRQoL, distress, and loneliness during the first wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

In April 2020, 4984 patients included in the nationwide Prospective Dutch Colorectal Cancer cohort were invited to complete a COVID-19–specific questionnaire, together with the validated European Organisation for Research and Treatment of Cancer Core Quality of Life Questionnaire (QLQ-C30), De Jong Gierveld, and Hospital Anxiety and Depression Scale. Clinical data were obtained from the Netherlands Cancer Registry. Scores were compared with the year prior to COVID-19 and with an age- and sex-matched control population during COVID-19.

Results

In total, 3247 (65.1%) patients responded between April and June 2020. Of the patients, 17% had canceled, postponed, or changed hospital visits to a telephone or video consult, and 5.3% had adjusted, postponed, or canceled treatment. Compared with controls, patients reported worse HRQoL but comparable distress and less social loneliness (patients = 21.2%; controls = 32.9%). Compared with pre–COVID-19, clinically meaningful deterioration of HRQoL was more prevalent in patients with changes in cancer care planning than in patients without changes. Prior to undergoing or currently undergoing treatment and infection worries were associated with lower HRQoL.

Conclusions

CRC patients reported equal anxiety and depression but worse HRQoL than the control population. Changes in care planning were associated with deterioration of HRQoL and increased anxiety. In case of 1 or more risk factors, health-care specialists should discuss (mental) health status and possible support during future SARS-CoV-2 infection waves or comparable pandemics.

Basic Aspects of Seasonal Cardiovascular Mortality

The review demonstrates the main aspects of seasonal cardiovascular mortality. Climatic factors, including seasonal weather changes, have a significant impact on the biosphere. People are also characterized by the seasonal dynamics of the activity of many organs and systems, biochemical parameters, and mortality. Cardiovascular mortality is also characterized by seasonal fluctuations: in winter it is maximum, in summer it is minimal. The same patterns are characteristic of mortality from cardiovascular diseases (myocardial infarction, stroke, cardiac arrhythmias, etc.). The article presents the basic patterns of seasonal cardiovascular mortality in various climatic zones, the cardiovascular mortality of countries located in the equatorial and subequatorial climatic region. In addition, the mortality displacement phenomenon, the paradox of winter mortality. The main trends in changes in cardiovascular mortality over a long period of time are demonstrated. The paper discusses some of the mechanisms that underlie the dynamics of cardiovascular mortality during the year: seasonal fluctuations in the level of vitamin D, lipids in the blood plasma, changes in hemodynamic parameters, the effects of microbial and viral infections in the cold season, etc. In addition, data on seasonal the dynamics of risk factors for cardiovascular diseases is considered: an increase in body weight, a physical activity decrease, a change in the nutrition structure in the winter, the seasonal dynamics of depression, anxiety, hostility, the relationship of seasonal cardiovascular mortality with socio-economic, demographic and other factors. In conclusion, the main ways of development and prevention of seasonal CV cardiovascular mortality M, taking into account modern technologies at the international level, for state health departments, for specific patients, are demonstrated.

Seasonality of mood and affect in a large general population sample

Mood and behaviour are thought to be under considerable influence of the seasons, but evidence is not unequivocal. The purpose of this study was to investigate whether mood and affect are related to the seasons, and what is the role of neuroticism in this association. In a national internet-based crowdsourcing project in the Dutch general population, individuals were invited to assess themselves on several domains of mental health. ANCOVA was used to test for differences between the seasons in mean scores on the Positive and Negative Affect Schedule (PANAS) and Quick Inventory of Depressive Symptomatology (QIDS). Within-subject seasonal differences were tested as well, in a subgroup that completed the PANAS twice. The role of neuroticism as a potential moderator of seasonality was examined. Participants (n = 5,282) scored significantly higher on positive affect (PANAS) and lower on depressive symptoms (QIDS) in spring compared to summer, autumn and winter. They also scored significantly lower on negative affect in spring compared to autumn. Effect sizes were small or very small. Neuroticism moderated the effect of the seasons, with only participants higher on neuroticism showing seasonality. There was no within-subject seasonal effect for participants who completed the questionnaires twice (n = 503), nor was neuroticism a significant moderator of this within-subjects effect. The findings of this study in a general population sample participating in an online crowdsourcing study do not support the widespread belief that seasons influence mood to a great extent. For, as far as the seasons did influence mood, this only applied to highly neurotic participants and not to low-neurotic participants. The underlying mechanism of cognitive attribution may explain the perceived relation between seasonality and neuroticism.

Functional Dyspepsia: A Narrative Review With a Focus on Sex-Gender Differences

Functional dyspepsia (FD) is among the most common gastrointestinal disorders affecting quality of life (QoL). As it frequently occurs in women than in men the comparison of various aspects including prevalence, clinical manifestations, and QoL in FD between women and men is very important for understanding the disease distribution and burden, evaluating treatment options, developing new drugs, and allocating medical resources. However, little is known about sex or gender differences among patients with FD. In spite of limited studies, consistent points are that FD occurs more often in women than in men and there are several symptom differences between men and women with FD. In addition, women with FD tend to have lower QoL than men with FD. Similarly, the pathophysiology of FD likely to vary depending on gender. Furthermore, a sex-gender-oriented approach in healthcare system could enhance understanding heterogeneous patients suffering from FD. Due to the sex-gender differences in physiological and psychological factors, treatment strategies should differ between women and men with FD. In conclusion, an individualized and multicomponent approach that considers sex and gender issues might improve FD treatment and improve patient Qol, especially for women.

Effects of vitamin D supplementation on depression and some involved neurotransmitters

BACKGROUND

Low vitamin D levels are associated with a dysregulated hypothalamic-pituitary-adrenal (HPA) axis and depression but a causal relationship has not been established. This study aimed to evaluate the effects of vitamin D supplementation on depression severity, serum 25(OH)D, and some neurotransmitters in patients with mild to moderate depression.

METHODS

An 8-week double-blind randomized clinical trial was conducted on 56 subjects with mild to moderate depression, aged 43.0 ± 1.15yrs. The patients were randomly allocated into two groups: intervention (50,000 IU cholecalciferol/2wks) and control (placebo). Biochemical parameters (serum 25(OH)D, iPTH, oxytocin and platelet serotonin), and depression severity (Beck Depression Inventory-II (BDI-II¹)) were initially and finally assessed.

RESULTS

Following intervention, significant changes were observed in the intervention group compared to the controls: 25(OH)D concentrations increased (+40.83±28.57 vs. +5.14±23.44 nmol/L, P<0.001) and BDI scores decreased (-11.75±6.40 vs. -3.61±10.40, P = 0.003). Oxytocin concentrations were significantly reduced in controls (-6.49±13.69 ng/mL, P = 0.01), but between -group differences were insignificant. Within- and between-group differences of platelet serotonin concentrations were not significant; however, the increment in controls was higher (+0.86±10.82 vs. +0.26±9.38 ng/mL, P = 0.83).

LIMITATIONS

Study duration may not reflect the long-term effects of vitamin D on depression. It seems necessary to assess tryptophan-hydroxylasetypes1&2 in relation to vitamin D in serotonin pathways.

CONCLUSIONS

Eight-week supplementation with 50,000 IU/2wks vitamin D, elevated 25(OH)D concentration of subjects with mild to moderate depression and significantly improved their depression severity. However, there was no evidence that the anti-depressive effect of vitamin D supplementation is mediated by the measured neurotransmitters.

Seasonal fluctuations in psychological distress amongst women diagnosed with early breast cancer receiving radiotherapy

OBJECTIVE

Seasonal effects on patients diagnosed with depression/anxiety-related psychological disorders have varying impacts on symptom severity. Seasonal changes in psychological distress may be due to decreased daylight exposure during the fall/winter seasons. Patients receiving radiation therapy (RT) for early-stage invasive breast cancer (EIBC) are at high risk for developing depressive symptoms. Of interest is whether seasonal factors influence the psychological symptoms of patients being treated for EIBC.

METHODS

Patients treated with RT for EIBC between January 2011 and June 2017 were identified. Patients who completed at least one Edmonton Symptom Assessment Scale (ESAS-r) pre-RT and post-RT were included in our analysis. Patients receiving RT during the autumn and winter (November-March) were compared with patients receiving RT during the spring and summer (April-August). Psychological distress was evaluated based on patient-reported depression, anxiety, and overall wellbeing on the ESAS-r. Data on systemic treatment and radiation were extracted from existing databases.

RESULTS

Eight-four patients treated with RT in spring/summer and 102 patients treated with RT in autumn/winter were included. Patients receiving RT during spring/summer had better wellness score prior to RT, compared with those receiving RT during winter/autumn (P = .03). However, patients receiving RT in the spring/summer had worse symptom trajectories across three domains of depression, anxiety, and wellbeing (P = .03, P = .008, and P < .0001, respectively).

CONCLUSIONS

Seasonality influenced the symptoms reported by patients with EIBC receiving RT. Future studies are needed to understand when during treatment patients are at highest risk for psychological distress and how seasonality may influence high-risk periods.

Seasonal Variations in the Severity of ADHD Symptoms in the Dutch General Population

OBJECTIVE

This is the first study to examine self-reported seasonal differences in the severity of ADHD symptoms in adults from the general population.

METHOD

Data were analyzed from N = 5,303 respondents participating in the second wave of the Netherlands Mental Health Survey and Incidence Study-2, a population-based study on mental health. ADHD symptoms were assessed using the Adult ADHD Self-Report Scale Screener. As indicators of the severity of ADHD symptoms, the total ADHD symptom score and inattention and hyperactivity subscale scores were examined.

RESULTS

Compared with participants who were assessed in autumn, total ADHD and inattention subscale scores were significantly higher among participants who were assessed in spring or summer; the hyperactivity subscale score was significantly higher in spring.

CONCLUSION

We found seasonal variations in the severity of ADHD symptoms, which was highest in those assessed in spring and summer. Researchers should be aware of this in the diagnostic process.

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.

No evidence of seasonal variation in mild forms of depression

BACKGROUND AND OBJECTIVES

Seasonal Affective Disorder (SAD) is ubiquitous in popular culture and has influenced psychiatric diagnosis with the inclusion of the seasonal pattern modifier for the Major Depressive Episode in DSM. However, recent research has not supported the association of Major Depressive Episode with seasonal changes. The present study was conducted to determine if a seasonally-related pattern of occurrence of mild variants of depression could be demonstrated in a population-based study.

METHODS

This is a cross-sectional U.S. survey of adults who completed the PHQ-8 Depression Scale with mild depression defined using a PHQ-8 cut score and a second model based on the DSM-5 diagnosis, Depression with insufficient symptoms. Regression models were used to determine if either variant of mild depression was related to season, latitude, or measures of daylight hours.

RESULTS

Neither measure of mild depression was related to daylight hours or its proxy measures.

LIMITATIONS

Screening instruments for depression, even if consistent with DSM-5 diagnostic criteria, do not allow a formal diagnosis of depression or the exclusion of similar-appearing disorders. Current depression symptoms but not duration of depressive episode is measured.

CONCLUSIONS

Mild depression is not related to seasonal changes or proxy measures of light exposure. The findings cast doubt on light deficiency as a causal factor of depressive disorders, which underpins the inclusion of the seasonal pattern modifier in DSM-5 and light supplementation as a treatment modality.

Seasonality of depressive symptoms during pregnancy

Various risk factors have been identified for antepartum depression. This study evaluated seasonal influences on antepartum depressive symptoms. Data of 2,438 pregnant women on current depressive symptoms was obtained from a large-scale cross-sectional study in The Netherlands. Most women were screened during the first trimester. Depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale (EPDS) and dichotomized using ≥ 9 as cut-off score. The seasonal relationship between antepartum depressive symptoms and the month of assessment was estimated by fitting a sinusoidal curve to the data. A total of 323 women (13.2%) scored above cut-off. In the full sample, we found no significant evidence for seasonal influences on depressive symptoms after adjusting for confounders. Additionally, we found that the seasonal influence was obscured by the modification of the effect by current treatment status. In women untreated for psychiatric complaints, we found a minimum of depressive symptomatology in September and a maximum in March. In women treated for psychiatric complaints we found a minimum of depressive symptomatology in December and a maximum in June. Thus, the effects of seasonality are apparent, but opposite in treated and untreated women. However, health professionals should be aware of depressive symptoms the whole year through.

Seasonal variation in major depressive episode prevalence in Canada

BACKGROUND

The purpose of this paper is to describe variation, over the months of the year, in major depressive episode (MDE) prevalence. This is an important aspect of the epidemiological description of MDE, and one that has received surprisingly little attention in the literature. Evidence of seasonal variation in MDE prevalence has been weak and contradictory. Most studies have sought to estimate the prevalence of seasonal affective disorder using cut-points applied to scales assessing mood seasonality rather than MDE. This approach does not align with modern classification in which seasonal depression is a diagnostic subtype of major depression rather than a distinct category. Also, some studies may have lacked power to detect seasonal differences. We addressed these limitations by examining the month-specific occurrence of conventionally defined MDE and by pooling data from large epidemiological surveys to enhance precision in the analysis.

METHOD

Data from two national survey programmes (the National Population Health Survey and the Canadian Community Health Survey) were used, providing ten datasets collected between 1996 and 2013, together including over 500,000. These studies assessed MDE using a short form version of the Composite International Diagnostic Interview (CIDI) for major depression, with one exception being a 2012 survey that used a non-abbreviated version of the CIDI. The proportion of episodes occurring in each month was evaluated using items from the diagnostic modules and statistical methods addressing complex design features of these trials. Overall month-specific pooled estimates and associated confidence intervals were estimated using random effects meta-analysis and a gradient was assessed using a meta-regression model that included a quadratic term.

RESULTS

There was considerable sampling variability when the month-specific proportions were estimated from individual survey datasets. However, across the various datasets, there was sufficient homogeneity to justify the pooling of these estimated proportions, producing large gains in precision. Seasonal variation was clearly evident in the pooled data. The highest proportion of episodes occurred in December, January and February and the lowest proportions occurred in June, July and August. The proportion of respondents reporting MDE in January was 70% higher than August, suggesting an association with implications for health policy. The pattern persisted with stratification for age group, sex and latitude.

CONCLUSIONS

Seasonal effects in MDE may have been obscured by small sample sizes in prior studies. In Canada, MDE has clear seasonal variation, yet this is not addressed in the planning of services. These results suggest that availability of depression treatment should be higher in the winter than the summer months.

Seasonal affective disorder, winter type: current insights and treatment options

Seasonal affective disorder (SAD), winter type, is a seasonal pattern of recurrent major depressive episodes most commonly occurring in autumn or winter and remitting in spring/summer. The syndrome has been well-known for more than three decades, with light treatment being the treatment of first choice. In this paper, an overview is presented of the present insights in SAD. Description of the syndrome, etiology, and treatment options are mentioned. Apart from light treatment, medication and psychotherapy are other treatment options. The predictable, repetitive nature of the syndrome makes it possible to discuss preventive treatment options. Furthermore, critical views on the concept of SAD as a distinct diagnosis are discussed.

Seasonal variations in sleep disorders of nurses

AIMS AND OBJECTIVES

To investigate the difference between nurses and the general population regarding seasonal variations in sleep disorders during 2004-2008. The effects of season and group interaction on sleep disorders with regard to different comorbidities were also examined.

BACKGROUND

Studies on seasonal variations in sleep disorders were mainly conducted in Norway for the general population. Furthermore, whether different comorbidities cause seasonal variations in sleep disorders in nurses remains unknown.

DESIGN

A retrospective study.

METHODS

Data from the Taiwan National Health Insurance Research Database were used in generalised estimating equation Poisson distribution models to investigate the differences in sleep disorders between nurses and the general population diagnosed with sleep disorders (each n = 7643) as well as the interaction effects of sleep disorders between the groups with respect to different seasons. Furthermore, the interaction effects between groups and seasons on sleep disorders in the subgroups of comorbid anxiety disorders and depressive disorders were studied.

RESULTS

Both the nurses and the general population had fewer outpatient visits for sleep disorders in winter than in other seasons. The nurses had fewer outpatient visits for sleep disorders than the general population did in each season. The nurses had more outpatient visits for sleep disorders in winter than in summer compared with the general population in the comorbid depressive disorder subgroup but not in the comorbid anxiety disorder subgroup.

CONCLUSIONS

Nurses and the general population exhibited similar seasonal patterns of sleep disorders, but nurses had fewer outpatient visits for sleep disorders than the general population did in each season. For nurses with comorbid depressive disorders, outpatient visits for sleep disorders were more numerous in winter than in summer, potentially because nurses with comorbid depressive disorders are affected by shorter daylight exposure during winter.

RELEVANCE TO CLINICAL PRACTICE

Depression and daylight exposure may be considered in mitigating sleep disorders in nurses.

Childhood disintegrative disorder with seasonal total mutism: A rare clinical presentation

Childhood disintegrative disorder (CDD) is a rare autistic-like clinical condition with unknown etiology, in that previously acquired age-appropriate language, social and adaptive abilities deteriorate significantly in 2-10-year-old healthy children, although physical and neurological evaluations display no observable abnormality. Our case is a 22-year-old female born of a consanguineous marriage, with the appearance of CDD symptoms in her fifth year of age following normal mental and physical development during her initial four years of life. Without any precipitating factor, she gradually lost her language abilities, social relational skills, affectionate behavior, adaptive capacities, peer play and meaningful interest in her surrounding, friends and family members over a period of 4 years, reaching a plateau in her ninth year of age. The unique special clinical symptom in this case is a seasonal total mutism, which after the beginning of her CDD symptoms is revealing every year covering the spring. As no additional physical or psychological change accompanies her total seasonal speech loss, it cannot be attributed to any mental condition known as having a seasonal pattern. Because in the literature CDD is presented mostly as case reports with lacking of advanced research data, describing any new case is recommended to improve the knowledge about this rare condition, especially if it displays some new unusual signs, not reported till now.

Seasonal and meteorological associations with depressive symptoms in older adults: A geo-epidemiological study

BACKGROUND

Given increased social and physiological vulnerabilities, older adults may be particularly susceptible to environmental influences on mood. Whereas the impact of season on mood is well described for adults, studies rarely extend to elders or include objective weather data. We investigated the impact of seasonality and meteorological factors on risk of current depressive symptoms in older adults.

METHODS

We used data on 8027 participants from the first wave of The Irish Longitudinal Study of Ageing, a population-representative cohort of adults aged 50+. Depressive symptoms were recorded using the Centre for Epidemiological Studies Depression Scale. Season was defined according to the World Meteorological Organisation. Data on climate over the preceding thirty years, and temperature and rain over the preceding month, were provided by the Irish Meteorological Service and linked using Geographic Information Systems techniques to participant's geo-coded locations at a resolution of one kilometre.

RESULTS

The highest levels of depressive symptoms were reported in winter and the lowest in spring (mean 6.56 [CI95% 6.09, 7.04] vs. 5.81 [CI95%: 5.40, 6.22]). In fully adjusted linear regression models, participants living in areas with higher levels of rainfall in the preceding and/or current calendar month had greater depressive symptoms (0.04 SE 0.02; p=0.039 per 10mm additional rainfall per month) while those living in areas with sunnier climates had fewer depressive symptoms (-2.67 SE 0.88; p=0.003 for every additional hour of average annual daily sunshine).

LIMITATIONS

This was a cross-sectional analysis thus causality cannot be inferred; monthly rain and temperature averages were available only on a calendar month basis while monthly local levels of sunshine data were not available.

CONCLUSIONS

Environmental cues may influence mood in older adults and thus have relevance for the recognition and treatment of depression in this age group.

Seasonal variation in clinical remission of primary care patients with depression: impact of gender

RATIONALE, AIMS AND OBJECTIVES

The impact of seasonal variation on clinical remission in patients with depression has not been well studied. The hypothesis for this study was that the clinical remission rate would be lower in the winter comparing to the other seasons, specifically evaluated by gender.

METHODS

The study cohort comprised 2873 primary care patients with depression as a longitudinal retrospective chart review analysis. The sample was limited to patients who were continuing in care; dropouts were excluded from the analysis.

RESULTS

Multivariate logistic regression analysis of the independent variables for those participants who achieved clinical remission demonstrated that for the male patients, the season of diagnosis did not impact the rate of remission at 6 months while controlling for all other independent variables. For female patients, those that were diagnosed with depression in the fall had increased likelihood of 6-month remission compared with those patients diagnosed in the winter months (OR 1.300, CI 1.006-1.680, P=0.045) and the spring and summer patients were not significantly different in their outcome rates. When both genders were combined, the odds of remission at 6 months were not statistically significant for any season of diagnosis.

CONCLUSIONS

This study demonstrates that in patients who were continuing care, women who were diagnosed with major depression or dysthymia in the fall season have improved 6-month clinical outcome of remission compared with those women diagnosed in the winter, when controlling for demographic and clinical characteristics. This effect was not seen in men or when the genders were combined into a single cohort. The assessment of the seasonality effect on depression outcomes requires further long-term follow-up studies.

Seasonal variation of depressive symptoms in unipolar major depressive disorder

OBJECTIVES

Retrospective and cross-sectional studies of seasonal variation of depressive symptoms in unipolar major depression have yielded conflicting results. We examined seasonal variation of mood symptoms in a long-term prospective cohort - the Collaborative Depression Study (CDS).

METHODS

The sample included 298 CDS participants from five academic centers with a prospectively derived diagnosis of unipolar major depression who were followed for at least ten years of annual or semi-annual assessments. Generalized linear mixed models were utilized to investigate the presence of seasonal patterns. In a subset of 271 participants followed for at least 20 years, the stability of a winter depressive pattern was assessed across the first two decades of follow-up.

RESULTS

A small increase in proportion of time depressed was found in the months surrounding the winter solstice, although the greatest symptom burden was seen in December through April with a peak in March. The relative burden of winter depressive symptoms in the first decade demonstrated no relationship to that of the second decade. The onset of new episodes was highest October through January, peaking in January.

CONCLUSIONS

There exists a small but statistically significant peak in depressive symptoms from the month of the winter solstice to the month of the spring equinox. However, the predominance of winter depressive symptoms did not appear stable over the long-term course of illness.

Prevalence and correlates of depression among college nursing students in China

This study aims to assess the prevalence of depression and examine potential risk factors correlated to depression among nursing college students in China. Between September and November 2012, a total of 763 college nursing students were randomly selected to participate in a survey, which included the Center for Epidemiologic Studies Depression Scale (CES-D). The result showed that 22.9% (95% CI: 20.0%-25.9%) of participants reported high score on the CES-D (16 or above). Risk factors significantly associated with depression in the univariate analysis were academic performance, academic stress, interest in majors, occupational future, interpersonal relationship, frequency of exercise, self-reported health status, social support, educational level of father, relationship with parents and making decisions without interference by parents. Backward multivariate logistic regression analysis revealed that lower academic stress, and better occupational future were strongly related to lower risk of depression, followed by active use of social support, full making decision power, better relationship with father and higher self-reported health status. The findings suggested that in order to prevent depression among college nursing students, school- and family-based strategies should be developed and implemented.

Data-driven discovery of seasonally linked diseases from an Electronic Health Records system

BACKGROUND

Patterns of disease incidence can identify new risk factors for the disease or provide insight into the etiology. For example, allergies and infectious diseases have been shown to follow periodic temporal patterns due to seasonal changes in environmental or infectious agents. Previous work searching for seasonal or other temporal patterns in disease diagnosis rates has been limited both in the scope of the diseases examined and in the ability to distinguish unexpected seasonal patterns. Electronic Health Records (EHR) compile extensive longitudinal clinical information, constituting a unique source for discovery of trends in occurrence of disease. However, the data suffer from inherent biases that preclude an identification of temporal trends.

METHODS

Motivated by observation of the biases in this data source, we developed a method (Lomb-Scargle periodograms in detrended data, LSP-detrend) to find periodic patterns by adjusting the temporal information for broad trends in incidence, as well as seasonal changes in total hospitalizations. LSP-detrend can sensitively uncover periodic temporal patterns in the corrected data and identify the significance of the trend. We apply LSP-detrend to a compilation of records from 1.5 million patients encoded by ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification), including 2,805 disorders with more than 500 occurrences across a 12 year period, recorded from 1.5 million patients.

RESULTS AND CONCLUSIONS

Although EHR data, and ICD-9 coded records in particular, were not created with the intention of aggregated use for research, these data can in fact be mined for periodic patterns in incidence of disease, if confounders are properly removed. Of all diagnoses, around 10% are identified as seasonal by LSP-detrend, including many known phenomena. We robustly reproduce previous findings, even for relatively rare diseases. For instance, Kawasaki disease, a rare childhood disease that has been associated with weather patterns, is detected as strongly linked with winter months. Among the novel results, we find a bi-annual increase in exacerbations of myasthenia gravis, a potentially life threatening complication of an autoimmune disease. We dissect the causes of this seasonal incidence and propose that factors predisposing patients to this event vary through the year.

Geographical and climatic factors and depression risk in the SUN project

BACKGROUND

Depression incidence has been related with seasonal periodicity and climate. The aim of the study was to estimate the possible association between depression and specific meteorological factors, namely temperature, light and rain.

METHODS

In total, 13,938 participants from the SUN (Seguimiento Universidad de Navarra) cohort study were included in the analysis. Subjects were classified according to daily mean temperature, number of daylight hours and amount of rain, by year, at their geographical area of residence, data supplied by the Spanish Agency of Meteorology. Participants were considered as incident cases of depression whenever they reported a physician diagnosis of depression or the use of antidepressant medication in any of the follow-up questionnaires. Cox regression models were fit to assess the relationship between climatic and geographical factors and the incidence of depression.

RESULTS

Male subjects living in the south and centre areas of Spain showed a higher risk to develop depression compared with those living in the north area (hazard ratio = 1.6, 95% CI = 1.16-2.23 and hazard ratio = 1.41, 95% CI = 1.06-1.87, respectively). Moreover, among males, a direct association between the number of daily light hours and mean temperature and the risk of depression was also found. For men, living in rainy areas was associated with a lower risk of developing depression.

CONCLUSION

Our results suggest that climate-depression relationship is more complex than previously thought, and strongly different between men and women.

Effect of Helicobacter pylori Eradication on Functional Dyspepsia

Background/Aims

This study evaluated the effect of Helicobacter pylori eradication on functional dyspepsia (FD), and the relationship between the changes of histological gastritis and FD symptom responses.

Methods

A total of 213 FD patients diagnosed by Rome III criteria were consecutively enrolled. H. pylori tests and gastritis grade by the Sydney system were performed before and 1 year after the proton pump based-eradication therapy for 7 days. Serum levels of pepsinogen, and genetic polymorphisms IL-6, IL-8 and IL-10 were investigated.

Results

Total of 91 patients completed the 1 year follow-up. When the response rate of dyspepsia was compared at 1 year between the non-eradicated group (n = 24) and eradicated group (n = 67), each group showed complete response of 62.5% and 62.7%; satisfactory response (≥ 50%) of 0.0% and 19.4%; partial response (< 50%) of 12.5% and 11.9%; and refractory response of 25.0% and 6.0%, respectively (P = 0.015). In addition, the responder group (complete + satisfactory response) at 1 year showed improvement of activity and chronic inflammation in both the antrum and corpus (all P < 0.001). Multivariate analysis showed that H. pylori eradication (OR, 5.81; 95% CI, 1.07-31.59) and symptom improvement at 3 month (OR, 28.90; 95% CI, 5.29-157.82) were associated with the improvement of dyspepsia at 1 year. Among the successfully eradicated FD patients (n = 67), male (P = 0.013) and higher initial BMI (P = 0.016) were associated with the improvement of dyspepsia at 1 year.

Conclusions

H. pylori eradication improved FD symptoms, as well as gastritis at 1 year, suggesting that inflammation mediates FD.

Serum BDNF concentrations show strong seasonal variation and correlations with the amount of ambient sunlight

Earlier findings show seasonality in processes and behaviors such as brain plasticity and depression that in part are regulated by Brain-Derived Neurotrophic Factor (BDNF). Based on this we investigated seasonal variation in serum BDNF concentrations in 2,851 persons who took part in the Netherlands Study of Depression and Anxiety (NESDA). Analyses by month of sampling (monthly n's >196) showed pronounced seasonal variation in serum BDNF concentrations (P<.0001) with increasing concentrations in the spring-summer period (standardized regression weight (ß) = 0.19, P<.0001) and decreasing concentrations in the autumn-winter period (ß = -0.17, P<.0001). Effect sizes [Cohen's d] ranged from 0.27 to 0.66 for monthly significant differences. We found similar seasonal variation for both sexes and for persons with a DSM-IV depression diagnosis and healthy control subjects. In explorative analyses we found that the number of sunshine hours (a major trigger to entrain seasonality) in the week of blood withdrawal and the 10 weeks prior to this event positively correlated with serum BDNF concentrations (Pearson's correlation coefficients ranged: 0.05-0.18) and this could partly explain the observed monthly variation. These results provide strong evidence that serum BDNF concentrations systematically vary over the year. This finding is important for our understanding of those factors that regulate BDNF expression and may provide novel avenues to understand seasonal dependent changes in behavior and illness such as depression. Finally, the findings reported here should be taken into account when designing and interpreting studies on BDNF.