Prevalence of winter depression in Denmark

Homo temporus: Seasonal Cycles as a Fundamental Source of Variation in Human Psychology

Many animal species exhibit seasonal changes in their physiology and behavior. Yet despite ample evidence that humans are also responsive to seasons, the impact of seasonal changes on human psychology is underappreciated relative to other sources of variation (e.g., personality, culture, development). This is unfortunate because seasonal variation has potentially profound conceptual, empirical, methodological, and practical implications. Here, we encourage a more systematic and comprehensive collective effort to document and understand the many ways in which seasons influence human psychology. We provide an illustrative summary of empirical evidence showing that seasons impact a wide range of affective, cognitive, and behavioral phenomena. We then articulate a conceptual framework that outlines a set of causal mechanisms through which seasons can influence human psychology-mechanisms that reflect seasonal changes not only in meteorological variables but also in ecological and sociocultural variables. This framework may be useful for integrating many different seasonal effects that have already been empirically documented and for generating new hypotheses about additional seasonal effects that have not yet received empirical attention. The article closes with a section that provides practical suggestions to facilitate greater appreciation for, and systematic study of, seasons as a fundamental source of variation in human psychology.

Predictability of Seasonal Mood Fluctuations Based on Self-Report Questionnaires and EEG Biomarkers in a Non-clinical Sample

Induced by decreasing light, people affected by seasonal mood fluctuations may suffer from low energy, have low interest in activities, experience changes in weight, insomnia, difficulties in concentration, depression, and suicidal thoughts. Few studies have been conducted in search for biological predictors of seasonal mood fluctuations in the brain, such as EEG oscillations. A sample of 64 participants was examined with questionnaires and electroencephalography in summer. In winter, a follow-up survey was recorded and participants were grouped into those with at least mild (N = 18) and at least moderate (N = 11) mood decline and those without self-reported depressive symptoms both in summer and in winter (N = 46). A support vector machine was trained to predict mood decline by either EEG biomarkers alone, questionnaire data from baseline alone, or a combination of the two. Leave-one-out-cross validation with lasso regularization was used with logistic regression to fit a model. The accuracy for classification for at least mild/moderate mood decline was 77/82% for questionnaire data, 72/82% for EEG alone, and 81/86% for EEG combined with questionnaire data. Self-report data was more conclusive than EEG biomarkers recorded in summer for prediction of worsening of depressive symptoms in winter but it is advantageous to combine EEG with psychological assessment to boost predictive performance.

Recordkeeping Error or Strategic Seasonal Substitution?: The Seasonality of Occupational Injuries in SOII and MarketScan

OBJECTIVE

I compare the seasonal patterns observed in the Survey of Occupational Injuries and Illnesses (SOII) to claims data from the IBM® MarketScan® Research Databases.

METHODS

I construct monthly injury rates and claims rates by supplementing occupational injuries and other claims data with hours data from the Current Population Survey and estimate seasonal effects using an Unobservable Components Model.

RESULTS

While workers' compensation data and the SOII display similar seasonal patterns, the year-end decline in the MarketScan data is 1/3 to 1/2 the magnitude observed in the SOII. Short-term disability and private health insurance claims display seasonal patterns inversely related to occupational injuries.

CONCLUSIONS

Part of the year-end decline in occupational injuries observed in the SOII is likely due to recordkeeping error. There is also some evidence of strategic seasonal substitution between various health-compensation alternatives.

Psoriasis and seasonal variation: A systematic review on reports from Northern and Central Europe-Little overall variation but distinctive subsets with improvement in summer or wintertime

BACKGROUND

Positive influence of the sun on psoriasis is a common assumption in dermatology. Other season-related factors such as mental health may interfere. However, the role of seasonal effects on psoriasis needs to be clarified. This review aims to systematically analyze the literature on seasonal variation on psoriasis with emphasis on Northern and Central Europe representing temperate climate conditions.

MATERIALS AND METHODS

Enrolled literature was identified through PubMed, EMBASE, and BIOSIS. An additional manual search of old reports before the introduction of efficient modern therapies, which can interfere with the spontaneous disease, was performed.

RESULTS

Thirteen studies were enrolled. About 50% of psoriasis patients were stable and showed no seasonal difference between seasons. Approximately 30% improved in summer, and 20% performed better in winter, some with marked summer worsening. European results matched international reports from different continents and hemispheres with climate extremes. The psychological effects could not be ruled out.

CONCLUSION

About 50% of psoriasis patients experience a season-independent disease, however, with a subset of patients who do better in summer. Others again do better in winter, with a few of these having marked worsening in warm periods. Individual season-related activity records should be paid proper attention to when considering light therapy or climatotherapy as a treatment.

Seasonal sensitivity and psychiatric morbidity: study about seasonal affective disorder

BACKGROUND

Seasonal Affective Disorder is a recurrent depressive disorder which usually begins in the fall/winter and enters into remission in the spring/summer, although in some cases may occur in the summer with remission in the autumn-winter. In this study the authors evaluated the association between seasonal changes in mood and behavior with psychiatric disturbance.

METHOD

Descriptive, cross-sectional study. Participants, students attending higher education and vocational courses (N = 324), were evaluated with the Seasonal Pattern Assessment Questionnaire (SPAQ) and the Screening Scale for Mental Health (ER80).

RESULTS

Among the respondents, 12.7% showed seasonal affective disorder (SAD), 29.0% showed subsyndromal seasonal affective disorder (s-SAD) and 58.3% did not show significant seasonal affective symptomatology. As for psychiatric morbidity, 36.6% of subjects with SAD and 13.8% of those with s-SAD were considered "psychiatric cases" whereas for subjects without SAD this value was only 3.2%.

CONCLUSIONS

There is a statistically significant association between psychiatric morbidity and seasonal affective disorder. This association corroborates the importance of the Seasonal Pattern Assessment Questionnaire in screening for seasonal fluctuations in mood and behavior related disorders, and the clinical need for recognition of these conditions, particularly associated suffering and disabilities.

Self-reported seasonality is strongly associated with chronotype and weakly associated with latitude

The aim of this study was to investigate the association between self-reported seasonality, i.e., seasonal variations in mood and related behavior, and chronotype, and between self-reported seasonality and home address' latitude. Data were collected from an online questionnaire with 45,338 participants. Seasonality and chronotype were measured with the Global Seasonality Score (GSS) and the Composite Scale of Morningness, respectively. The participants were categorized into extreme morning types, moderate morning types, intermediate types, moderate evening types, and extreme evening types. Furthermore, participants were categorized depending on home address' latitude. Data were analyzed with chi-square tests and logistic regression analyses adjusting for sex, age, marital status, level of education, and children living at home. Results showed that high seasonality (GSS 11+) was found in 20.9%. The prevalence dose-dependency ranged from 12.2% in extreme morning types to 42.6% in extreme evening types (adjusted OR = 4.21, CI = 3.27-5.41). The prevalence was higher in participants living in North-Norway (latitude from 65 to 71⁰N) versus South-Norway (latitude from 58 to 65⁰N) (23.8% versus 20.7%; adjusted OR = 1.18, CI = 1.08-1.28). When comparing the northernmost (69-71⁰N) to the southernmost (58-59⁰N) counties of Norway, the association was stronger (24.9% versus 18.7%; adjusted OR = 1.37, CI = 1.20-1.56). Among the adjusting variables, high seasonality was associated with female sex, younger age, being unmarried, low level of education, and not having children living at home. In conclusion, about one in five Norwegians reported high seasonality. High seasonality was strongly associated with late chronotype (being an evening type) and weakly associated with living in the north (high latitude).

Sensory processing sensitivity and its association with seasonal affective disorder

It has been hypothesized that an increased sensitivity to the surroundings, can leave some individuals vulnerable to experience the environmental stress of winter more overwhelming, thus leading to a greater risk of Seasonal Affective Disorder (SAD). However, the association between trait Sensory Processing Sensitivity (SPS) and SAD is not known. We therefore aimed to investigate: 1)cross-seasonal group differences in trait SPS, in 31 individuals with SAD compared to 30 age-, gender- and education-matched healthy controls, and 2)the association between trait SPS in remitted phase (summer) and depression severity in symptomatic phase (winter) in individuals with SAD. All participants completed the Highly Sensitive Person Scale, as a measure of SPS, and the Major Depression Inventory in summer and in winter, using a longitudinal and seasonally counterbalanced design. In both remitted and symptomatic phase, individuals with SAD exhibited higher trait SPS compared to healthy controls, which for individuals with SAD was heightened during depression in winter. Notably, when averaged across season, about 25% of the individuals with SAD display high-sensitivity whereas this is only the case for 5% of the healthy controls. In addition, higher trait SPS in summer was associated with more severe SAD symptoms in winter. Our findings suggest that those with SAD are more likely to score high on SPS and that high SPS may be a vulnerability marker related to more severe SAD symptomatology.

Seasonality-resilient individuals downregulate their cerebral 5-HT transporter binding in winter - A longitudinal combined 11C-DASB and 11C-SB207145 PET study

We have recently shown that the emergence and severity of seasonal affective disorder (SAD) symptoms in the winter is associated with an increase in cerebral serotonin (5-HT) transporter (SERT) binding. Intriguingly, we also found that individuals resilient to SAD downregulate their cerebral SERT binding in the winter. In the present paper, we provide an analysis of the SERT- and 5-HT dynamics as indexed by 5-HT₄ receptor (5-HT4R) binding related to successful stress coping. We included 46 ¹¹C-DASB positron emission tomography (PET) scans (N = 23, 13 women, age: 26 ± 6 years) and 14 ¹¹C-SB207145 PET scans (7 participants, 3 women, age: 25 ± 3 years) from 23 SAD-resilient Danes. Data was collected longitudinally in summer and winter. We found that compared to the summer, raphe nuclei and global brain SERT binding decreased significantly in the winter (p_raphe = 0.003 and p_global = 0.003) and the two measures were positively correlated across seasons (summer: R² = 0.33, p = .004, winter: R² = 0.24, p = .018). A voxel-based analysis revealed prominent changes in SERT in clusters covering both angular gyri (0.0005 < p_corrected < 0.0016), prefrontal cortices (0.00087 < p_corrected < 0.0039) and the posterior temporal and adjacent occipital cortices (0.0001 < p_corrected < 0.0066). We did not observe changes in 5-HT4R binding, suggesting that 5-HT levels remained stable across seasons. We conclude that resilience to SAD is associated with a global downregulation of SERT levels in winter which serves to keep 5-HT levels across seasons.

Self-perceived personality characteristics in seasonal affective disorder and their implications for severity of depression

The personality traits Neuroticism and Extraversion may be involved in the development of seasonal affective disorder (SAD). However, the impact of personality traits on SAD severity and whether such self-reported traits fluctuate with season is unknown. We investigated the association between Neuroticism, as acquired in a symptom-free phase and depression severity in individuals with SAD and seasonal changes in personality traits in individuals with SAD compared to healthy controls. Twenty-nine individuals diagnosed with SAD and thirty demographically matched controls completed the NEO Personality Inventory-Revised and the Major Depression Inventory twice: in summer when individuals with SAD were symptom-free, and in winter when they experienced SAD symptoms. In summer, the groups scored similarly on their personality traits, and the controls did not score any different in winter compared to summer. High scores on Neuroticism in summer was associated with more severe depressive symptoms in winter in SAD individuals. In winter, individuals with SAD scored higher on Neuroticism and lower on Extraversion, both compared to controls and to their own summer scores. Our results support that Neuroticism may represent a vulnerability marker related to SAD, and during a depressive episode Neuroticism and Extraversion may be sensitive markers of SAD pathology.

Amygdala response to emotional faces in seasonal affective disorder

BACKGROUND

Seasonal affective disorder (SAD) is characterized by seasonally recurring depression. Heightened amygdala activation to aversive stimuli is associated with major depressive disorder but its relation to SAD is unclear. We evaluated seasonal variation in amygdala activation in SAD and healthy controls (HC) using a longitudinal design targeting the asymptomatic/symptomatic phases of SAD. We hypothesized increased amygdala activation to aversive stimuli in the winter in SAD individuals (season-by-group interaction).

METHODS

Seventeen SAD individuals and 15 HCs completed an implicit emotional faces BOLD-fMRI paradigm during summer and winter. We computed amygdala activation (SPM5) to an aversive contrast (angry & fearful minus neutral) and angry, fearful and neutral faces, separately. Season-by-group and main effects were evaluated using Generalized Least Squares. In SAD individuals, we correlated change in symptom severity, assessed with The Hamilton Rating Scale for Depression - Seasonal Affective Disorder version (SIGH-SAD), with change in amygdala activation.

RESULTS

We found no season-by-group, season or group effect on our aversive contrast. Independent of season, SAD individuals showed significantly lower amygdala activation to all faces compared to healthy controls, with no evidence for a season-by-group interaction. Seasonal change in amygdala activation was unrelated to change in SIGH-SAD.

LIMITATIONS

Small sample size, lack of positive valence stimuli.

CONCLUSIONS

Amygdala activation to aversive faces is not increased in symptomatic SAD individuals. Instead, we observed decreased amygdala activation across faces, independent of season. Our findings suggest that amygdala activation to angry, fearful and neutral faces is altered in SAD individuals, independent of the presence of depressive symptoms.

Season-independent cognitive deficits in seasonal affective disorder and their relation to depressive symptoms

Although cognitive impairments are common in depressed individuals, it is unclear which aspects of cognition are affected and whether they represent state or trait features of depression. We here exploited a naturalistic model, namely the seasonal fluctuations in depressed status in individuals with Seasonal Affective Disorder (SAD), to study depression-related cognition, longitudinally. Twenty-nine medication-free individuals diagnosed with winter-SAD and 30 demographically matched healthy controls with no seasonality symptoms completed the Letter-number Sequencing task (LNS), the Symbol Digit Modalities Test (SDMT) and the Simple Reaction Time (SRT) twice; in summer and in winter. Compared to controls, SAD individuals showed significant season-independent impairments in tasks measuring working memory (LNS), cognitive processing speed (SDMT) and motor speed (SRT). In SAD individuals, cognitive processing speed was significantly negatively associated with the seasonal change in SAD depressive symptoms. We present novel evidence that in SAD individuals, working memory, cognitive processing- and motor speed is not only impaired in the winter but also in the summer. This suggests that certain cognitive impairments are SAD traits. Furthermore, impairments in cognitive processing speed appear to be related to depressive symptoms in SAD. Reduced processing speed may thus constitute a SAD vulnerability trait marker.

Prevention of seasonal affective disorder in daily clinical practice: results of a survey in German-speaking countries

BACKGROUND

Seasonal affective disorder (SAD) is a seasonally recurrent type of major depression. This predictable aspect makes it promising for preventive treatment. However, evidence for the efficacy and harm of preventive treatment of SAD is scarce, as are recommendations from clinical practice guidelines. The aim of this study was to assess the current use of preventive treatment of SAD in clinical practice in German-speaking countries for the first time.

METHODS

We conducted a postal and web-based survey sent to the heads of all psychiatric institutions listed in the inventory "Deutsches Krankenhaus Adressbuch, 2015" that contains all psychiatric hospitals in Germany, Austria, and Switzerland.

RESULTS

One hundred institutions (out of 533 institutions, 19%), which treated in total more than 3100 SAD patients in the years 2014/2015, responded. Of those, 81 reported recommending preventive treatment to patients with a history of SAD. There was no consensus on the optimal starting point for preventive treatment. Most of the institutions that implemented prevention of SAD, recommended lifestyle changes (85%), antidepressants (84%), psychotherapy (73%), and light therapy (72%) to their patients. The situation was similar in northern and southern regions.

CONCLUSIONS

Most hospitals recommended the use of preventive treatment to SAD patients, although evidence on efficacy and harm is limited. A wide variety of interventions were recommended, although guidelines only include recommendations for acute treatment. To assist psychiatrists and patients in future decision making, controlled studies on preventive treatment for SAD that compare different interventions with one another are needed.

The Medical use of Cannabis in Germany

The author first describes the history of medical use of cannabis and its revival in the 1990s. He then provides an overview of the legal situation and how this affects doctors and patients if cannabis is prescribed or recommended as treatment. Subsequently, the state of the art of cannabis medication research is described and analyzed. Finally, the public and political discourse that arose in reaction to legal and political efforts to legalize cannabis for medical purposes is described.

Seasonal variations in mood and behavior associate with common chronic diseases and symptoms in a population-based study

The purpose of this study was to assess how seasonality is associated with some of the most common non-communicable diseases (NCDs) in the general Finnish population. The global seasonality score (GSS) was used to measure the magnitude of seasonality in 4689 participants, in addition to which they reported the extent to which the seasonal variations in mood and behavior were experienced as a problem. Regression models and the odds ratios were adopted to analyze the associations adjusted for a range of covariates. Seventy percent of the participants had seasonal variations in sleep duration, social activity, mood, or energy level, and forty percent those in weight and appetite. Angina pectoris and depression were significantly associated with seasonality throughout the analysis. Hypertension, high cholesterol levels, diabetes, other (than rheumatoid) joint diseases and other (than depressive) psychological illnesses were significantly associated with experiencing a problem due to the seasonal variations, with an increase in the GSS, and with seasonal affective disorder and its subsyndromal form. The co-occurrence of the seasonal variations in mood and behavior with certain common NCDs warrants future research to have insights into the etiology and potentially shared pathways and mechanisms of action.

Cerebrospinal Fluid Hypocretin-1 (Orexin-A) Level Fluctuates with Season and Correlates with Day Length

The hypocretin/orexin neuropeptides (hcrt) are key players in the control of sleep and wakefulness evidenced by the fact that lack of hcrt leads to the sleep disorder Narcolepsy Type 1. Sleep disturbances are common in mood disorders, and hcrt has been suggested to be poorly regulated in depressed subjects. To study seasonal variation in hcrt levels, we obtained data on hcrt-1 levels in the cerebrospinal fluid (CSF) from 227 human individuals evaluated for central hypersomnias at a Danish sleep center. The samples were taken over a 4 year timespan, and obtained in the morning hours, thus avoiding impact of the diurnal hcrt variation. Hcrt-1 concentration was determined in a standardized radioimmunoassay. Using biometric data and sleep parameters, a multivariate regression analysis was performed. We found that the average monthly CSF hcrt-1 levels varied significantly across the seasons following a sine wave with its peak in the summer (June-July). The amplitude was 19.9 pg hcrt/mL [12.8-26.9] corresponding to a 10.6% increase in midsummer compared to winter. Factors found to significantly predict the hcrt-1 values were day length, presence of snow, and proximity to the Christmas holiday season. The hcrt-1 values from January were much higher than predicted from the model, suggestive of additional factors influencing the CSF hcrt-1 levels such as social interaction. This study provides evidence that human CSF hcrt-1 levels vary with season, correlating with day length. This finding could have implications for the understanding of winter tiredness, fatigue, and seasonal affective disorder. This is the first time a seasonal variation of hcrt-1 levels has been shown, demonstrating that the hcrt system is, like other neurotransmitter systems, subjected to long term modulation.

Epidemiology and socioeconomic impact of seasonal affective disorder in Austria

BACKGROUND

Seasonal affective disorder (SAD) is a subtype of recurrent depressive or bipolar disorder that is characterized by regular onset and remission of affective episodes at the same time of the year. The aim of the present study was to provide epidemiological data and data on the socioeconomic impact of SAD in the general population of Austria.

METHODS

We conducted a computer-assisted telephone interview in 910 randomly selected subjects (577 females and 333 males) using the Seasonal Health Questionnaire (SHQ), the Seasonal Pattern Assessment Questionnaire (SPAQ), and the Sheehan Disability Scale (SDS). Telephone numbers were randomly drawn from all Austrian telephone books and transformed using the random last digits method. The last birthday method was employed to choose the target person for the interviews.

RESULTS

Out of our subjects, 2.5% fulfilled criteria for the seasonal pattern specifier according to DSM-5 and 2.4% (95% CI=1.4-3.5%) were diagnosed with SAD. When applying the ICD-10 criteria 1.9% (95% CI=0.9-2.8%) fulfilled SAD diagnostic criteria. The prevalence of fall-winter depression according to the Kasper-Rosenthal criteria was determined to be 3.5%. The criteria was fulfilled by 15.1% for subsyndromal SAD (s-SAD). We did not find any statistically significant gender differences in prevalence rates. When using the DSM-5 as a gold standard for the diagnosis of SAD, diagnosis derived from the SPAQ yielded a sensitivity of 31.8% and a specificity of 97.2%. Subjects with SAD had significantly higher scores on the SDS and higher rates of sick leave and days with reduced productivity than healthy subjects.

CONCLUSIONS

Prevalence estimates for SAD with the SHQ are lower than with the SPAQ. Our data are indicative of the substantial burden of disease and the socioeconomic impact of SAD. This epidemiological data shows a lack of gender differences in SAD prevalence. The higher rates of females in clinical SAD samples might, at least in part, be explained by lower help seeking behaviour in males.

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.

Maternal vitamin D status and offspring bone fractures: prospective study over two decades in Aarhus City, Denmark

Background

Studies investigating the association between maternal vitamin D status and offspring bone mass measured by dual-energy X-ray absorptiometry (DXA) during childhood have shown conflicting results.

Purpose

We used occurrence of bone fractures up to the age of 18 as a measure reflecting offspring bone mass and related that to maternal vitamin D status.

Methods

The Danish Fetal Origins 1988 Cohort recruited 965 pregnant women during 1988–89 at their 30^th gestation week antenatal midwife visit. A blood sample was drawn and serum was stored, which later was analyzed for the concentration of 25-hydroxyvitamin D (25(OH)D) by the liquid chromatography coupled with a tandem mass spectrometric method (LC-MS/MS). Outcome was diagnosis of first time bone fractures extracted from the Danish National Patient Register.

Results

Vitamin D status was available for 850 women. The median (5^th–95^th percentile) 25(OH)D was 76.2 (23.0–152.1) nmol/l. During follow up 294 children were registered with at least one bone fracture diagnosis. Multivariable Cox regression models using age as the underlying time scale indicated no overall association between maternal vitamin D status and first time bone fractures. However, there was a significantly increased hazard ratio (HR) during childhood for those who had maternal blood drawn in Dec/Jan/Feb compared with Jun/Jul/Aug (HR: 1.75, 95%CI: 1.11–2.74). Adjustment for vitamin D status strengthened this association (1.82, 1.12–2.97), which indicated a potential seasonal impact on offspring fractures independent of maternal vitamin D status. In a sensitivity analysis we found a borderline significant inverse association between continuous concentrations of 25(OH)D and offspring forearm fractures (P = 0.054).

Conclusion

Overall, our results did not substantiate an association between maternal vitamin D status and offspring bone fractures. Further studies on this subject are needed, but the study populations must be large enough to allow for subdivision of fractures.

Seasonality of mood and behavior in the Old Order Amish

BACKGROUND/OBJECTIVE

We examined seasonality and winter seasonal affective disorder (SAD) in the Old Order Amish of Lancaster County, Pennsylvania, a unique population that prohibits use of network electric light in their homes.

METHODS

We estimated SAD using the seasonal pattern assessment questionnaire (SPAQ) in 1306 Amish adults and compared the frequencies of SAD and total SAD (i.e., presence of either SAD or subsyndromal-SAD) between men and women, young and old, and awareness of (ever vs. never heard about) SAD. Heritability of global seasonality score (GSS) was estimated using the maximum likelihood method, including a household effect to capture shared environmental effects.

RESULTS

The mean (±SD) GSS was 4.36 (±3.38). Prevalence was 0.84% (95% CI: 0.36-1.58) for SAD and 2.59% (95% CI: 1.69-3.73) for total SAD. Heritability of GSS was 0.14±0.06 (SE) (p=0.002) after adjusting for age, gender, and household effects.

LIMITATIONS

Limitations include likely overestimation of the rates of SAD by SPAQ, possible selection bias and recall bias, and limited generalizability of the study.

CONCLUSIONS

In the Amish, GSS and SAD prevalence were lower than observed in earlier SPAQ-based studies in other predominantly Caucasian populations. Low heritability of SAD suggests dominant environmental effects. The effects of awareness, age and gender on SAD risk were similar as in previous studies. Identifying factors of resilience to SAD in the face of seasonal changes in the Amish could suggest novel preventative and therapeutic approaches to reduce the impact of SAD in the general population.

Do behavioral disturbances predict falls among nursing home residents?

BACKGROUND AND AIMS

The purpose of our study was to examine whether severity of dementia, behavioral and psychological symptoms and depression can predict falls among nursing home residents, such as demographic variables, activities of daily living, and use of psychotropic drugs, when potential confounders are controlled for.

METHODS

1147 nursing home residents were examined in this one-year follow-up study. All residents were examined with the Physical Self-Maintenance scale (Activities of Daily Living - ADL), Clinical Dementia Rating Scale (CDR), Neuropsychiatric Inventory (NPI) and Cornell Scale for Depression in Dementia. Demographic data, gender, education, physical health and use of medication were collected from medical records.

RESULTS

40% of participants had at least one fall during the one-year follow-up period. Bivariate survival analysis revealed that low level of education, severe dementia, severe behavioral and psychological symptoms, severe depression, greater functional impairment, age, worsening in physical health, and use of sedatives, significantly predict one or more falls. Multivariate Cox regression analyses showed that age, higher scores on NPI and CDR, use of sedatives and dependency in ADL were all, independently of each other, predictors of an increased risk of falling.

CONCLUSIONS

Having a high NPI score was identified as a significant and independent predictor of falls. Since falling is a common event which causes considerable morbidity and mortality in older people, these findings are important for healthcare and for the individuals concerned. To prevent falling in nursing homes, special attention must be paid to residents with severe dementia, to behavioral symptoms and use of sedatives.

Study protocol: a cross-sectional survey of seasonal affective disorder in Danish populations with and without severe visual impairments

INTRODUCTION

People with seasonal affective disorder (SAD) experience recurrent seasonal fluctuations in energy, mood and appetite. Retinal light exposure is suggested to play an important role in the pathogenesis and treatment of SAD. The aim of the study is to determine the prevalence of SAD in persons with severe visual impairments or blindness and to compare the results to a control group without visual impairments. Moreover, the authors wish to investigate whether SAD is correlated to the degree of impairment or to the diagnosis.

METHODS AND ANALYSIS

2781 persons with visual impairments ranging from total blindness to Snellen visual acuity 6/60 receive information letter and questionnaire by post. Completed questionnaires can be returned by post, email or telephone. For each respondent, all eye-related diagnoses will be obtained from national registries. Normally sighted and demographically matched control respondents will be contacted in a similar manner the subsequent winter season. The Seasonal Pattern Assessment Questionnaire rates seasonal variation within the six items: sleep, appetite, social activity, mood, energy and body weight. The Seasonal Pattern Assessment Questionnaire yields a Global Seasonal Score and a prevalence of SAD. Outcomes from the two groups will be compared. Moreover, outcomes from subgroups of the visually impaired population will be compared.

ETHICS AND DISSEMINATION

The study is approved by the Danish Data Protection Agency. Results will be published in a relevant scientific journal and be communicated to respondents and relevant institutions through cooperation with the Danish Association of the Blind.

Increased health risk in subjects with high self-reported seasonality

BACKGROUND

Seasonal variations in mood and behaviour, termed seasonality, are commonly reported in the general population. As a part of a large cross-sectional health survey in Hordaland, Norway, we investigated the relationship between seasonality, objective health measurements and health behaviours.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 11,545 subjects between 40-44 years old participated, completing the Global Seasonality Score, measuring seasonality. Waist/hip circumference, BMI and blood pressure were measured, and blood samples were analyzed for total cholesterol, HDL cholesterol, triglycerides and glucose. Subjects also completed a questionnaire on miscellaneous health behaviours (exercise, smoking, alcohol consumption). Hierarchical linear regression analyses were used to investigate associations between seasonality and objective health measurements, while binary logistic regression was used for analysing associations between seasonality and health behaviours. Analyses were adjusted for sociodemographic factors, month of questionnaire completion and sleep duration. Seasonality was positively associated with high waist-hip-ratio, BMI, triglyceride levels, and in men high total cholesterol. Seasonality was negatively associated with HDL cholesterol. In women seasonality was negatively associated with prevalence of exercise and positively associated with daily cigarette smoking.

CONCLUSIONS/SIGNIFICANCE

High seasonality was associated with objective health risk factors and in women also with health behaviours associated with an increased risk for cardiovascular disease.

The prevalence of seasonal affective disorder (SAD) in Greenland is related to latitude

The aim of this study was to determine the prevalence of seasonal affective disorder (SAD) in Greenlanders and Danes living at four different latitudes in Greenland. A Seasonal Pattern Assessment Questionnaire (SPAQ) was mailed to 6021 men and women between the ages of 18 and 59 years living in four different municipalities in Greenland. The recipients were randomly selected from the National Population Register. Approximately 9% of the respondents met the criteria for SAD, and the incidence of SAD varied between a southern municipality and three northern municipalities. The prevalence of SAD was particularly high in northern municipalities. No significant difference was found in the prevalence of SAD between Greenlanders and Danes. The results are comparable with other population studies that have reported a high prevalence of SAD in arctic areas. The clinical implications of our findings and the possibilities for introducing light therapy should be assessed in future studies.

Circadian photoreception: ageing and the eye's important role in systemic health

AIM

To analyse how age-related losses in crystalline lens transmittance and pupillary area affect circadian photoreception and compare the circadian performance of phakic and pseudophakic individuals of the same age.

METHODS

The spectral sensitivity of circadian photoreception peaks in the blue part of the spectrum at approximately 460 nm. Photosensitive retinal ganglion cells send unconscious information about environmental illumination to non-visual brain centres including the human body's master biological clock in the suprachiasmatic nuclei. This information permits human physiology to be optimised and aligned with geophysical day-night cycles using neural and hormonal messengers including melatonin. Age-related transmittance spectra of crystalline lenses and photopic pupil diameter are used with the spectral sensitivity of melatonin suppression and the transmittance spectra of intraocular lenses (IOLs) to analyse how ageing and IOL chromophores affect circadian photoreception.

RESULTS

Ageing increases crystalline lens light absorption and decreases pupil area resulting in progressive loss of circadian photoreception. A 10-year-old child has circadian photoreception 10-fold greater than a 95-year-old phakic adult. A 45-year-old adult retains only half the circadian photoreception of early youth. Pseudophakia improves circadian photoreception at all ages, particularly with UV-only blocking IOLs which transmit blue wavelengths optimal for non-visual photoreception.

CONCLUSIONS

Non-visual retinal ganglion photoreceptor responses to bright, properly timed light exposures help assure effective circadian photoentrainment and optimal diurnal physiological processes. Circadian photoreception can persist in visually blind individuals if retinal ganglion cell photoreceptors and their suprachiasmatic connections are intact. Retinal illumination decreases with ageing due to pupillary miosis and reduced crystalline lens light transmission especially of short wavelengths. Inadequate environmental light and/or ganglion photoreception can cause circadian disruption, increasing the risk of insomnia, depression, numerous systemic disorders and possibly early mortality. Artificial lighting is dimmer and less blue-weighted than natural daylight, contributing to age-related losses in unconscious circadian photoreception. Optimal intraocular lens design should consider the spectral requirements of both conscious and unconscious retinal photoreception.

Behavioral despair is differentially affected by the length and timing of photic stimulation in the dark phase of an L/D cycle

The effect of varying the length and timing of photic stimulation in the dark phase of an L/D lighting cycle on behavioral despair was investigated in female Wistar rats. Animals were kept in a vivarium on an L/D 12 h:12 h light cycle (lights on at 0700 h) except for a single day of light exposure in an insulated chamber in the dark phase of the L/D schedule. Light pulses provided by an incandescent lamp (15- and 25-W, for Exps. 1 and 2, respectively) either 2-h (Exp. 1) or 30-min in length (Exp. 2) were administered to independent groups of rats (n=8 each) either in the early, middle or late hours of the dark phase of the L/D cycle in the insulated chamber. Light pulses were delivered beginning 2 1/2, 5 1/2 or 7 1/2 h (Exp. 1) or 3 1/4, 6 1/4 and 8 1/4 h (Exp. 2) after dark onset. Control animals were treated similarly except for photic stimulation. In each experiment, an additional group received a light pulse of the appropriate length both in the early and late portion of the dark phase (double double-pulse groups): beginning 2 1/2 and 7 1/2 h (Exp. 1) or 3 1/4 and 8 1/4 h (Exp. 2) after dark onset. All animals then underwent two forced swim tests separated by 24 h with the first test occurring in the light (starting at 1500 h) following the dark phase when photic stimulation was administered. Total duration of immobility in the second swim test was measured to gauge behavioral despair. In Exp. 1, the 2-h double double-pulse group showed significantly shorter immobility compared to controls (p<0.05). In Exp. 2, 30-min light pulse delivered late in the dark phase reduced immobility significantly compared to controls and all the other light-treated groups (p<0.01). Results indicate that photic stimulation may have antidepressant effect on behavioral despair depending on the timing and the duration of photic stimulation.

Seasonality is associated with anxiety and depression: the Hordaland health study

BACKGROUND

The purpose of this study was to assess how seasonal changes in mood and behaviour were associated with depression and anxiety symptoms in a sample from a general population, and to investigate how prevalence figures were affected by month of questionnaire completion.

METHODS

The target population included all individuals in the Hordaland county (Norway) born 1953-57 (N=29,400). In total, 8598 men (57% response rate) and 9983 women (70% response rate) attended the screening station. Half of the men (randomly chosen) and all of the women were offered a questionnaire to fill in with items on seasonality. This was measured using the Global Seasonality Score (GSS), a central component of the Seasonal Pattern Assessment Questionnaire (SPAQ). The Hospital Anxiety and Depression Scale (HADS) was used to measure anxiety and depression. Both questionnaires were completed by 2980 men (68.9%) and 8074 women (80.9%).

RESULTS

Seasonality was positively associated with levels of both anxiety and depression regardless of the season the interview took place. In subjects with a low/moderate degree of seasonality there were modestly higher levels of depressive symptoms during November through March than the other months.

LIMITATIONS

We had a substantial number of non-responders.

CONCLUSIONS

Our results raise the possibility of seasonality being a separate dimensional trait associated with both anxiety and depression.

The evolutionary significance of depressive symptoms: different adverse situations lead to different depressive symptom patterns

Although much depression may be dysfunctional, the capacity to experience normal depressive symptoms in response to certain adverse situations appears to have been shaped by natural selection. If this is true, then different kinds of situations may evoke different patterns of depressive symptoms that are well suited to solving the adaptive challenges specific to each situation. The authors called this the situation-symptom congruence hypothesis. They tested this hypothesis by asking 445 participants to identify depressive symptoms that followed a recent adverse situation. Guilt, rumination, fatigue, and pessimism were prominent following failed efforts; crying, sadness, and desire for social support were prominent following social losses. These significant differences were replicated in an experiment in which 113 students were randomly assigned to visualize a major failure or the death of a loved one.

Seasonal variations in mood and behaviour associated with gender, annual income and education: the Hordaland Health Study

OBJECTIVE

To explore the relationship between demographic factors and seasonal changes in mood and behaviour.

METHOD

A health survey was conducted among 40-45 year old inhabitants in Hordaland County, Norway. The Global Seasonality Score, investigating seasonal symptoms, was given to 4299 men and 9983 women. Response rates among those receiving the questionnaire were 79.8% for men (n = 3432) and 81.2% for women (n = 8223).

RESULTS

High seasonality was reported by 18.4% of men and 22.2% of women. Female gender, low educational level, high level of affective symptomatology and low household income correlated with high seasonality. Among men, being single was also a determinant factor for high seasonality. Reported seasonality also depended on which month the questionnaire was filled in.

CONCLUSIONS

In this study, high seasonality was most prevalent among females, being single, having a low annual income and a low education level. The latter two findings are different from expectations which could be drawn from previous studies suggesting an opposite association.

A warm heart and a clear head. The contingent effects of weather on mood and cognition

Prior studies on the association between weather and psychological changes have produced mixed results. In part, this inconsistency may be because weather's psychological effects are moderated by two important factors: the season and time spent outside. In two correlational studies and an experiment manipulating participants' time outdoors (total N = 605), pleasant weather (higher temperature or barometric pressure) was related to higher mood, better memory, and "broadened" cognitive style during the spring as time spent outside increased. The same relationships between mood and weather were not observed during other times of year, and indeed hotter weather was associated with lower mood in the summer. These results are consistent with findings on seasonal affective disorder, and suggest that pleasant weather improves mood and broadens cognition in the spring because people have been deprived of such weather during the winter.

High prevalence of self-reported winter depression in a Swedish county

The prevalence of winter depression was unknown in Sweden, therefore prevalence figures of seasonal affective disorder (SAD) and subsyndromal SAD (S-SAD) were estimated. Age and gender differences, prevalence in the group of non-responders and some psychometric qualities of the Seasonal Pattern Assessment Questionnaire (SPAQ) were calculated. A modified version of the SPAQ was sent to a random sample of 2500 persons (response rate 66.3%, n=1657) between 18 and 64 years residing in Dalarna, a county in central Sweden. The sample was proportionally stratified according to age, gender and home municipality. The prevalence of winter SAD was estimated at 8% and S-SAD at 10.8%. It was approximately twice as common among women and younger persons. A total of 3.1% reported seasonal problems to be severe or disabling and 19.3% that everyday life was negatively affected. Experiencing seasonally changing depressive symptoms was common in the population. Factor analysis of the Global Seasonal Score resulted in one factor and the internal consistency was 0.88 (Cronbach's alpha). The results indicate that self-reported recurrent depression during winter is common in Sweden and should therefore receive more attention from health care authorities.

The diagnosis, symptomatology, and epidemiology of seasonal affective disorder

The operational criteria for seasonal affective disorder (SAD) have undergone several changes since first proposed in 1984. SAD is currently included as a specifier of either bipolar or recurrent major depressive disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The International Classification of Diseases, Tenth Edition has provisional diagnostic criteria for SAD. The most characteristic quality of SAD is that the symptoms usually present during winter and remit in the spring. Furthermore, the symptoms tend to remit when the patients are exposed to daylight or bright light therapy. The cognitive and emotional symptoms are as in other types of depression but the vegetative symptoms are the reverse of classic depressive vegetative symptoms, namely increased sleep and increased appetite. SAD is a common condition, but the exact prevalence rates vary between different studies and countries and is consistently found to be more common in women and in youth. SAD probably possibly occurs in children although not as commonly as in young adults. Some studies have found that certain ethnic groups who live at high northern latitudes may have adapted to the long arctic winter.

Adjunctive bright light in non-seasonal major depression

OBJECTIVE

Bright light treatment is an established treatment for Seasonal Affective Disorder, but in non-seasonal depression research results have been contrasting.

METHOD

This study was designed as a 5-week controlled, double-blind, parallel trial in out-patients with a diagnosis (DSM-IV) of non-seasonal major depression, randomized to either active treatment (white light, 10 000 lux, 1 h daily) or placebo treatment (red light, 50 lux, 30 min daily) and concomitant treatment with sertraline in both groups.

RESULTS

One hundred and two patients were included in the study. Analyses showed that on all used scales the reduction in depression scores was larger in the bright light group than in the dim light group, and this reached statistical significance on all observer rating scales and on the SCL-90R self-assessment scale. The HAM-D6 was the most sensitive scale to measure improvement at endpoint.

CONCLUSION

The study results support the use of bright light as an adjunct treatment to antidepressants in non-seasonal depression.

Is low mood an adaptation? Evidence for subtypes with symptoms that match precipitants

BACKGROUND

Although severe depression is dysfunctional, the capacity to experience normal low mood may be useful in certain fitness-threatening situations. Moreover, if specific kinds of situations recurred often enough in the course of evolution, natural selection may have shaped partially differentiated subtypes of low mood that are parallel to the subtypes of anxiety that protect against different kinds of danger. To test this hypothesis, we examined how symptoms of low mood differ depending upon the precipitating situation, and whether these differences match expectations of symptoms useful in each kind of situation.

METHOD

337 subjects who experienced a period of low mood within the last year wrote accounts describing perceived causes of their low mood and they filled out the CES-D depression inventory. Seven symptom scales were derived from analysis of CES-D data. Independent judges blindly coded the accounts into one of six precipitant categories.

RESULTS

Different untoward situations were associated with different symptoms that were predicted to be useful in those situations. Social losses (death of a loved one, romantic breakups, and social isolation) were associated with greater crying and arousal. Failure to reach a goal, stress, and winter seasons were associated with more fatigue and pessimism.

DISCUSSION

These results suggest that natural selection shaped not only a generic state of low mood but also partially differentiated subtypes shaped to cope with specific situations that were associated with fitness losses among our ancestors.

A single day of constant light (L/L) provides immunity to behavioral despair in female rats maintained on an L/D cycle

The present experiment investigated the potentially ameliorative effect of exposure to light in the dark phase of an 12:12 h daily lighting schedule (12L/12D cycle) on behavioral despair, an animal model of depression based on two forced swim tests separated by 24 h. Experimental groups of female Wistar rats were maintained on the 12L/12D cycle except for a single exposure to 12 h of light treatment in the dark phase of the 12L/12D cycle. Control animals were treated similarly except for light treatment. Animals then underwent one of two sets of behavioral tests starting on either the day light (or control) treatment ended (No Delay groups) or 24 h thereafter (Delay groups). The treatment for subgroups of light-treated and control animals tested with or without delay consisted of either two forced swim tests separated by 24 h or testing in the open field and elevated plus maze. Results indicated that a single exposure to a 12-h light treatment has protective effect on behavioral despair in groups tested with or without delay as measured by shorter duration of immobility in the second swim test compared to the controls. Light-treated and control animals behaved similarly in the open field and elevated plus-maze tests.

A dual vulnerability hypothesis for seasonal depression is supported by the seasonal pattern assessment questionnaire in relation to the temperament and character inventory of personality in a general population

BACKGROUND

Personality structure obtained from the psychobiological Temperament and Character Inventory (TCI) was studied in relation to self-reported seasonal variations in mood and behavior measured by the Seasonal Pattern Assessment Questionnaire (SPAQ).

METHODS

The subjects comprised 1761 adults (57.6% women) in the age range 35-85 years, enrolled in the Betula prospective random cohort study of Umea, Sweden.

RESULTS

Personality profiles of subjects who reported the occurrence of a high degree of seasonal variation as such were associated with a combination of high self-transcendence (ST) and high persistence (PS), irrespective of the level of harm avoidance (HA). Subjects who reported feeling worst in winter were associated with high HA, irrespective of the levels of ST and PS. Also, subjects feeling worst in summer or experiencing overall problems with seasonal variation were associated with high HA in their personality profiles. Using the SPAQ criteria to define seasonal affective disorder (SAD) or subsyndromal SAD (S-SAD), subjects with these disorders often had combinations of high self-transcendence (ST) and high persistence (PS), but with different associations with HA.

LIMITATIONS

No evaluations were made for SAD or subsyndromal SAD according to the DSM-IV or ICD 10 criteria.

CONCLUSIONS

Our results relating SPAQ with TCI give support for a dual vulnerability hypothesis for seasonal depression proposed in the literature, where it is attributed to a combination of a seasonal factor and a depression factor. Examining the literature regarding the relationships between the different TCI scales and monoamine neurotransmitter functions, those relationships suggest that these two vulnerability factors for seasonal depression may be modulated by different neurotransmitter systems.

Prevalence of seasonal affective disorder in primary care; a comparison of the seasonal health questionnaire and the seasonal pattern assessment questionnaire

BACKGROUND

Prevalence rates of SAD suggested by previous studies have ranged from 1 to 12% depending on the diagnostic criteria used. The Seasonal Pattern Assessment Questionnaire (SPAQ), a widely used screening tool, has been shown to have low specificity for SAD. The Seasonal Health Questionnaire (SHQ) was designed to better reflect the clinical criteria for SAD and has been shown to have a higher specificity then the SPAQ in a psychiatric outpatient setting.

OBJECTIVE

The current study was designed to assess the validity of the SHQ in general practice against systematic research interviews, to compare the sensitivity, specificity and positive predictive values of the SHQ and the SPAQ and to use these data to estimate the prevalence of SAD in primary care.

METHODS

809 subjects in a consecutive series of patients attending Southampton general practices in winter 2000/01 completed the SHQ followed by the SPAQ; 56 were interviewed using the Structured Clinical Interview for DSM (SCID).

RESULTS

The SHQ was more sensitive and specific than the SPAQ and had higher positive and negative predictive values in screening for SAD. The SPAQ indicated a prevalence of SAD of 10.7% (95% CI 8.6-13.1) while the SHQ provided a significantly lower estimate of 5.6% (95% CI 4.2-7.4).

An epidemiological study on gender differences in self-reported seasonal changes in mood and behaviour in a general population of northern Sweden

Gender differences have been reported regarding symptoms, prevalence and heritability of seasonal affective disorders (SAD). We focus on gender aspects in this study of self-reported seasonal changes in mood and behaviour in a general population. The Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 2620 adults (55.6% women) aged 35-85 years, enrolled in the Betula prospective random cohort study of Umeå, Sweden. October to February turned out to be suitable winter months. SAD was found in 2.2% and sub-syndromal SAD (S-SAD) in 5.7%. Women had about 1.5 times higher prevalences than men, and seasonality problems decreased with age in both genders. Preference for eating least was distributed with a peak in summer, whereas preference for eating most had a major peak in winter (winter eaters) and a minor peak in summer (summer eaters). Significantly more of winter eaters in women, and significantly more of summer eaters in men, felt worst in winter. Seasonal change in weight was considered significantly as a problem by women but not by men. Winter behaviour of sleeping most was considered significantly as a problem by men but not by women. Women reacted significantly to temperature-related changes (negatively to cold/short days and positively to hot/long days), whereas men reacted significantly to sunshine-related changes (negatively to cloudy days and positively to sunny days). Subtle gender differences may thus underlie the pathophysiology of seasonal problems. Studies of an eventual efficacy of treating SAD women with raised ambient temperature, and gender-specific comparisons with other therapies, would be of interest.

Seasonal variation in specific methods of suicide: a national register study of 20,234 Finnish people

BACKGROUND

Previous studies have suggested differences in seasonal variation of violent and non-violent suicides, but seasonal distribution of the specific methods of suicide is less clear.

METHOD

We investigated the seasonal distribution of the specific suicide methods for both genders during a 16-year period. The seasonal effect was explored by monthly ratio statistics from the large population-based data including all suicides in Finland during years 1980-1995 (n=20,234).

RESULTS

Hanging peaked in spring among both genders. In summer, the significant peaks were occurred in suicides by drowning, jumping and gassing among males. The bimodality in female suicides with autumn peaks was explained by poisoning and drowning. Traffic suicides showed substantial winter-troughs for both genders.

CONCLUSIONS

The results suggested that specific violent and nonviolent methods of suicides grouped into their traditional clusters on the basis of their seasonality, except suicides by gassing and shooting. The seasonal distribution in specific suicide methods should take into account in suicide prevention at clinical work and also it should be considered while determining which methods of suicides are regarded as violent or non-violent methods in research.

Seasonal affective disorder in an Arctic community

OBJECTIVE

To determine the rate of seasonal-pattern depression in an Inuit community above 70 degrees N.

METHOD

One-hundred and eleven people from randomly selected households were surveyed for depression and anxiety and the effect of the seasons on their mood. Eighty-eight people provided replies on the influence of the seasons.

RESULTS

One in five (22.6%) of the community sample was found to be depressed. Of these, seven (6.3%) had seasonal affective disorder (SAD), with fall onset occurring in six of these (5.4%). Subsyndromal SAD (SSAD) occurred in 11.7%, while any effect of the seasons (seasonality) occurred in 39.6%. Persons with SSAD and seasonality were significantly older than those unaffected by the seasonal effect. No other significant correlation of SAD, SSAD, or seasonality occurred with gender, age, and language preference.

CONCLUSION

Seasonal mood changes in this Inuit group living in the Canadian Arctic are elevated above the rates found in other studies using similar survey methods.

Seasonality and affective disorders: a report from North India

Case records of the patients with major affective disorders (ICD-10 criteria), seen over a 5 year period in a busy clinic in North India were examined for Seasonal Affective Disorder (SAD) as per DSM-III-R criteria. In addition, seasonality of episodes of all affective disorders was also studied. Around 5.67% of the cases (n=44) retrospectively met the DSM-III-R criteria of SAD and predominant pattern was that of summer depression (n=18). There was also a consistent pattern of seasonal mania either in conjunction with seasonal depression (n=18) or in form of seasonal recurrent mania (n=11). None of the cases of depression showed any atypical vegetative features. In cases not meeting criteria for SAD (n=731), there was a trend for peaks for depressive episodes in winter followed by a smaller peak in summer months while manic episodes had peaks towards rainy and winter months. As compared to seasonal patterns of affective disorders in temperate zones, there was a general trend for opposite patterns of seasonality in SAD as well as in non-SAD. The findings are discussed in context of the climatic conditions of North India.

The Seasonal Health Questionnaire: a preliminary validation of a new instrument to screen for seasonal affective disorder

BACKGROUND

The main screening tool for Seasonal Affective Disorder (SAD) is the Seasonal Pattern Assessment Questionnaire, but its reliability and validity have been thrown into doubt by several studies.

METHOD

In this study we developed a new questionnaire, the Seasonal Health Questionnaire (SHQ), which is scored by computer to derive the four main operational criteria for diagnosis of SAD. A group of clinically diagnosed SAD patients was contrasted with a group of patients with recurrent non-seasonal depressive disorder using the SPAQ and the SHQ.

RESULTS

The SHQ could be completed without difficulty by patients with long histories of recurrent mood disorder. The SPAQ and the Rosenthal Criteria were the least specific of the criteria for identifying SAD - misclassifying many non-seasonal patients.

CONCLUSIONS

After further development the SHQ may be a more appropriate screening instrument for SAD. The SPAQ should no longer be used for this purpose as it gives misleadingly high estimates of prevalence.

Bright light therapy of subsyndromal seasonal affective disorder in the workplace: morning vs. afternoon exposure

OBJECTIVE

Bright light therapy in seasonal affective disorder (SAD) has been studied extensively. However, little attention has been given to subsyndromal seasonal affective disorder (SSAD) or the use of bright light in the workplace. Many patients using bright light boxes complain of the inconvenience of use. Much of this inconvenience involves the often-recommended early timing of the bright light therapy. Patients, who already have difficulty awakening, often have difficulty using the bright light therapy soon after awakening before going to work. If bright light could be used effectively in the workplace, the treatment would be more convenient; the improved convenience would probably improve compliance. In this study, we studied the effectiveness of bright light therapy in subjects with SSAD in the workplace, comparing morning bright light with afternoon bright light.

METHOD

Morning and afternoon bright light treatment (2500 lux) were compared in 30 subsyndromal seasonal affective disorder patients using the bright light therapy in the workplace. Hamilton Depression Ratings and subjective measures of mood, energy, alertness and productivity were assessed before and after 2 weeks of light therapy.

RESULTS

Both morning and evening bright light significantly decreased the depression ratings and improved the subjective mood, energy, alertness and productivity scores. However, there were no significant differences between the two times of administration of the bright light treatment. Both bright light treatments were well tolerated.

CONCLUSION

Bright light given in the workplace improves subjective ratings of mood, energy, alertness and productivity in SSAD subjects. Morning and afternoon bright lights resulted in similar levels of improvement.

Estimated prevalence of the seasonal subtype of major depression in a Canadian community sample

OBJECTIVE

To examine estimates of lifetime prevalence of seasonal affective disorder (SAD) in Toronto, Ontario.

METHOD

Random telephone numbers were generated for the city of Toronto, and 781 respondents completed a telephone interview. Trained nonphysician interviewers conducted all interviews, which involved structured questions for diagnosing major depression. Patterns of symptom change across seasons were evaluated to establish a diagnosis of SAD according to DSM-III-R criteria.

RESULTS

Correcting for sex and age, the prevalence of SAD defined by DSM-III-R criteria was 2.9% (95% CI, 1.7% to 4.0%), and the overall lifetime prevalence of major depression in the sample was 26.4% (95% CI, 23.3% to 29.4%). Some subjects were contacted for a follow-up interview conducted in person; the positive predictive value for the diagnosis of major depression for the telephone interview was 100%, and the negative predictive value was 93%.

CONCLUSIONS

The seasonal subtype of depression represents 11% of all subjects with major depression, suggesting that SAD is a significant public health concern. The telephone interview demonstrated adequate reliability, indicating that it is appropriate for epidemiological surveys of this nature.

Long photoperiod regimen may produce antidepressant actions in the male rat

The exposure to bright light reverts the depressive symptoms of seasonally affective disorder. Rats received tricyclic antidepressants or were submitted to two photoperiod regimens. After treatments, the rats were forced to swim or were submitted to the differential reinforcement of the low-rate 72s schedule. Two animal models designed to testing the antidepressant effects of drugs. Clomipramine, desipramine or the long photoperiod decreased immobility in rats forced to swim. In the differential reinforcement of the low-rate 72s schedule, clomipramine, desipramine or the long photoperiod increased the reinforcers obtained by the rats. It is concluded that the long photoperiod regimen may produce antidepressant effects in male Wistar rats.