Physical Activity, Seasonal Sensitivity and Psychological Well-Being of People of Different Age Groups Living in Extreme Environments

Physical activity can prevent many organic and mental pathologies. For people living in extreme southern high-latitude environments, weather conditions can affect these activities, altering their psychological well-being and favoring the prevalence of seasonal sensitivity (SS). This study aims to determine the relationships between the practice of physical activity, seasonal sensitivity and well-being in people living in high southern latitudes. A cross-sectional study was conducted, using the Seasonal Pattern Assessment Questionnaire (SPAQ), applying a psychological well-being scale, and determining sports practice according to the recommendations of the World Health Organization (WHO) for the 370 male (n = 209; 55%) and female (n = 173; 45%) participants. The main results indicated that 194 people (52 ± 7.7 years) reported physical activity. High-intensity physical activity practitioners recorded a significantly lower proportion of SS. In terms of psychological well-being, an adverse effect was found between the Seasonal Score Index (SSI) and five subcategories of the Ryff well-being scale. In conclusion, those who perform high-intensity physical activity have a lower SS, and those who have a higher SS have a lower psychological well-being.

Seasonal affective disorder and engagement in physical activities among adults in Alaska

Seasonal affective disorder (SAD) is a type of depression in which symptoms occur during a particular season. While physical activity has been shown to improve symptoms for depression in general populations, the relationships between physical activity and experiences of seasonality and SAD remain underexplored. We conducted a survey with adult members of a recreational gym in Fairbanks, Alaska. The survey collected self-report data on sociodemographics, health behaviours, and elements of the Seasonal Pattern Assessment Questionnaire (SPAQ). Results indicate that 18.68% of our study participants meet the criteria for winter-pattern SAD and 43.96% meet the criteria for subsyndromal SAD ("winter blues"). We conducted two regressions to understand experiences of SAD and predictors of seasonality more generally. Gender was a significant predictor of SAD, with women more likely than men to experience SAD (p = .04). Being social at the gym, whether going to the gym with others or participating in activities with others, was associated with higher seasonality than being independent at the gym (p = .03). Younger age was also associated with higher seasonality (p < .001). This study contributes new insights about the relationship between engagement in physical activities and experiences of seasonality among adults in a northern latitude.

Effect of Hometown Seasonality on Undergraduate Students' Risk of Developing Seasonal Affective Disorder

Seasonal affective disorder (SAD) is a prevalent and potentially serious medical condition. Young adults are at particularly high risk. However, it is unknown if college students whose hometowns are in geographic areas with less seasonal variability, such as in the state of Hawai'i, are particularly vulnerable if they attend schools in areas with seasonal variability. An adapted version of the Seasonal Patterns Assessment Questionnaire (SPAQ) was administered to students at 3 universities to test this hypothesis. Surveys were administered twice: a baseline (T0) assessment in the fall and a follow-up (T1) assessment in the winter and were administered in the second month of each semester. A linear regression model was constructed to identify potential risk factors for developing seasonal fluctuations in mood (SPAQ scores T1-T0). Study subjects (n=115) from non-seasonal hometowns had a 1.6-point greater increase in SPAQ score than students from seasonal hometowns (-0.26 ± 3.88 vs 1.35 ± 3.03; P =.01). This difference is independent of demographic and lifestyle predictors (linear regression coefficient: β = 1.73; standard error = 0.68; P =.012). Interestingly, SPAQ score changes of students from seasonal hometowns did not differ significantly from 0 (t = -0.97; P =.33), indicating that they did not generally experience seasonal shifts in depressive symptoms. Students from less seasonal hometowns and counselors at seasonal institutions should be aware that these students could be more at risk of developing depressive symptoms and address these concerns before interfering with students' daily and academic lives.

Light and Hormones in Seasonal Regulation of Reproduction and Mood

Organisms that inhabit the temperate zone exhibit various seasonal adaptive behaviors, including reproduction, hibernation, molting, and migration. Day length, known as photoperiod, is the most noise-free and widely used environmental cue that enables animals to anticipate the oncoming seasons and adapt their physiologies accordingly. Although less clear, some human traits also exhibit seasonality, such as birthrate, mood, cognitive brain responses, and various diseases. However, the molecular basis for human seasonality is poorly understood. Herein, we first review the underlying mechanisms of seasonal adaptive strategies of animals, including seasonal reproduction and stress responses during the breeding season. We then briefly summarize our recent discovery of signaling pathways involved in the winter depression-like phenotype in medaka fish. We believe that exploring the regulation of seasonal traits in animal models will provide insight into human seasonality and aid in the understanding of human diseases such as seasonal affective disorder (SAD).

Prevalence of seasonal depression in a prospective cohort study

The prevalence of autumn/winter seasonality in depression has been documented in the longitudinal Zurich cohort study by five comprehensive diagnostic interviews at intervals over more than 20 years (N = 499). Repeated winter major depressive episodes (MDE-unipolar + bipolar) showed a prevalence of 3.44% (5× more women than men), whereas MDE with a single winter episode was much higher (9.96%). A total of 7.52% suffered from autumn/winter seasonality in major and minor depressive mood states. The clinical interviews revealed novel findings: high comorbidity of Social Anxiety Disorder and Agoraphobia within the repeated seasonal MDE group, high incidence of classic diurnal variation of mood (with evening improvement), as well as a high rate of oversensitivity to light, noise, or smell. Nearly twice as many of these individuals as in the other MDE groups manifested the syndrome of atypical depression (DSM-V), which supports the prior description of seasonal affective disorder (SAD) as presenting primarily atypical symptoms (which include hypersomnia and increase in appetite and weight). This long-term database of regular structured interviews provides important confirmation of SAD as a valid diagnosis, predominantly found in women, and with atypical vegetative symptoms.

The prevalence of seasonal affective disorder among the blind and patients with serious visual impairment

BACKGROUND

Seasonal affective disorder (SAD) is an interesting disorder in which depression should occur at a particular time of a year, each year and it should disappear at a specific time of the year. While the prevalence of SAD among generally healthy individuals is well known, the information about the prevalence of this disorder among the blind and visually impaired patients is very limited. The aim of the study was to investigate the prevalence of SAD among the blind and people with serious visual impairment in polish population.

SUBJECTS AND METHODS

250 blind or seriously visually impaired individuals and 258 healthy controls were assessed with the usage of Seasonal Pattern Assessment Questionnaire (SPAQ). In research group survey was conducted with the Computer Assisted Telephone Interview (CATI) technique. In control group the questionnaire was distributed via Internet. The results were analysed with the usage statistical package - Statistica 13.1.

RESULTS

The results revealed that among people suffering from SAD there is statistically significant difference in SPAQ scores between completely blind and seriously visually impaired people. The study shows that is the control group age is negatively correlated with score in SPAQ score, while in the study group age is positively correlated with SPAQ score. The data show that there is a difference in occurrence of SAD between men and women.

CONCLUSION

The study has shown a significant difference in occurrence of SAD between study and control groups. What is more the analysis has indicated major difference in the occurrence of SAD between men and women from the study group. Taking into consideration the fact that this is the second analysis of this type in Europe further investigations are needed.

Second-generation antidepressants for preventing seasonal affective disorder in adults

BACKGROUND

Seasonal affective disorder (SAD) is a seasonal pattern of recurrent major depressive episodes that most commonly occurs during autumn or winter and remits in spring. The prevalence of SAD ranges from 1.5% to 9%, depending on latitude. The predictable seasonal aspect of SAD provides a promising opportunity for prevention. This review - one of four reviews on efficacy and safety of interventions to prevent SAD - focuses on second-generation antidepressants (SGAs).

OBJECTIVES

To assess the efficacy and safety of SGAs (in comparison with other SGAs, placebo, light therapy, melatonin or agomelatine, psychological therapies or lifestyle interventions) in preventing SAD and improving patient-centred outcomes among adults with a history of SAD.

SEARCH METHODS

We searched Ovid MEDLINE (1950- ), Embase (1974- ), PsycINFO (1967- ) and the Cochrane Central Register of Controlled Trials (CENTRAL) to 19 June 2018. An earlier search of these databases was conducted via the Cochrane Common Mental Disorders Controlled Trial Register (CCMD-CTR) (all years to 11 August 2015). Furthermore, we searched the Cumulative Index to Nursing and Allied Health Literature, Web of Science, the Cochrane Library, the Allied and Complementary Medicine Database and international trial registers (to 19 June 2018). We also conducted a grey literature search and handsearched the reference lists of included studies and pertinent review articles.

SELECTION CRITERIA

For efficacy, we included randomised controlled trials (RCTs) on adults with a history of winter-type SAD who were free of symptoms at the beginning of the study. For adverse events, we planned to include non-randomised studies. Eligible studies compared a SGA versus another SGA, placebo, light therapy, psychological therapy, melatonin, agomelatine or lifestyle changes. We also intended to compare SGAs in combination with any of the comparator interventions versus placebo or the same comparator intervention as monotherapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened abstracts and full-text publications, extracted data and assessed risk of bias of included studies. When data were sufficient, we conducted random-effects (Mantel-Haenszel) meta-analyses. We assessed statistical heterogeneity by calculating the Chi2 statistic and the Cochran Q. We used the I2 statistic to estimate the magnitude of heterogeneity. We assessed publication bias by using funnel plots.We rated the strength of the evidence using the system developed by the GRADE Working Group.

MAIN RESULTS

We identified 3745 citations after de-duplication of search results and excluded 3619 records during title and abstract reviews. We assessed 126 full-text papers for inclusion in the review, of which four publications (on three RCTs) providing data from 1100 people met eligibility criteria for this review. All three RCTs had methodological limitations due to high attrition rates.Overall, moderate-quality evidence indicates that bupropion XL is an efficacious intervention for prevention of recurrence of depressive episodes in people with a history of SAD (risk ratio (RR) 0.56, 95% confidence interval (CI) 0.44 to 0.72; 3 RCTs, 1100 participants). However, bupropion XL leads to greater risk of headaches (moderate-quality evidence), insomnia and nausea (both low-quality evidence) when compared with placebo. Numbers needed to treat for additional beneficial outcomes (NNTBs) vary by baseline risks. For a population with a yearly recurrence rate of 30%, the NNTB is 8 (95% CI 6 to 12). For populations with yearly recurrence rates of 50% and 60%, NNTBs are 5 (95% CI 4 to 7) and 4 (95% CI 3 to 6), respectively.We could find no studies on other SGAs and no studies comparing SGAs with other interventions of interest, such as light therapy, psychological therapies, melatonin or agomelatine.

AUTHORS' CONCLUSIONS

Available evidence indicates that bupropion XL is an effective intervention for prevention of recurrence of SAD. Nevertheless, even in a high-risk population, three out of four people will not benefit from preventive treatment with bupropion XL and will be at risk for harm. Clinicians need to discuss with patients advantages and disadvantages of preventive SGA treatment, and might want to consider offering other potentially efficacious interventions, which might confer a lower risk of adverse events. Given the lack of comparative evidence, the decision for or against initiating preventive treatment of SAD and the treatment selected should be strongly based on patient preferences.Future researchers need to assess the effectiveness and risk of harms of SGAs other than bupropion for prevention of SAD. Investigators also need to compare benefits and harms of pharmacological and non-pharmacological interventions.

Eye disorder differentiates seasonality outcomes in persons with severe visual impairment

BACKGROUND

Light plays a crucial role in both the pathogenesis and treatment of seasonal affective disorder (SAD). Consequently decreased retinal sensitivity to light has been suggested to be a risk factor for SAD. In a population of persons with severe visual impairment we recently found a highly increased prevalence of SAD. We now aimed to identify eye disorders or anatomical locations with specific association to seasonality.

METHODS

In 912 cases (33%) from our prior seasonal pattern assessment questionnaire (SPAQ) screening study, we retrieved eye diagnoses from the Danish National Patient Registry and analyzed for specific eye disorders or anatomical locations that significantly differentiated SPAQ outcomes (global seasonality score, (GSS) and SPAQ-SAD prevalence).

RESULTS

Persons with early life eye disorders (congenital conditions or retinopathy of prematurity) reported less symptoms of SAD (median GSS 4.5) than persons with acquired eye disorders (median GSS 5.0, p=0.005). Persons with macular degenerative disorders (MD) had highly increased seasonality outcomes (hazard ratio 2.23, p=0.002, median GSS 5 vs. 8, p=0.01).

LIMITATIONS

the study is a cross-sectional study based on a self-report questionnaire. Register data may be incomplete.

CONCLUSIONS

MD is significantly associated to high-level seasonality and SAD prevalence. Early life eye disorder is associated to slightly lower seasonality compared to acquired eye disorder. Longitudinal studies are needed to assess causality.

Chromaticity of daylight: is the spectral composition of daylight an aetiological element in winter depression?

OBJECTIVES

Surveys on winter depression in Iceland indicate a significantly lower prevalence rate of winter SAD than expected according to Iceland's latitude. Research into daylight availability in Iceland failed to reveal factors contributing to higher average daylight availability than predicted by latitude. In view of the well-known healing effects of bright light treatment, we propose that properties of daylight other than daylight availability may ease the symptoms of winter depression.

METHOD

We analysed the spectral composition of daylight in Iceland as expressed by its chromaticity and assessed its seasonal and diurnal variations. The colorimetric properties of daylight during the year 1998 are dealt with in detail. Perception of daylight is modelled, applying the chromaticity model of MacLeod and Boynton along with environmental data on spectral irradiance recorded on location at 64 degrees 8.8' N and 21 degrees 55.8' W in Reykjavik, Iceland, and recently published data on cone fundamentals by Stockman and Sharpe.

RESULTS

The main finding is that blue hue dominates the colour of the sky, with high correlated colour temperature, without significant seasonal variations. Diurnal variations are, however, observed. Furthermore, significant deviation from 'standard' sky is detected.

CONCLUSIONS

It is not known whether the observed chromaticity of daylight is a significant factor in explaining the unexpectedly low prevalence rate of seasonal affective disorder in Iceland.

Daylight availability: a poor predictor of depression in Iceland

OBJECTIVES

To test the hypothesis that the unexpectedly low prevalence of winter depression in Iceland is explained by Icelanders enjoying more daylight, during the winter months, than allocated to them by latitude.

METHODS

A conventional photometer was applied to measure illuminance on a horizontal surface at 64 degrees 8.8' N and 21 degrees 55.8' W every minute throughout the year. The illuminance thus measured was compared with computed illuminance, based on theoretical upper bounds.

RESULTS

Daylight availability proved to be, on average, 60% of the theoretical upper bounds derived using clear sky conditions. Snow cover did not, on average, cause a significant increase in daylight availability. Great variability was observed in illuminance from day to day, as well as within days.

CONCLUSIONS

Average daylight availability does not explain the lower than expected prevalence of winter depression in Iceland. The great variability in illuminance might, however, affect the expression of winter depression, as could daylight quality and genetic factors.

Second-generation antidepressants for preventing seasonal affective disorder in adults

BACKGROUND

Seasonal affective disorder (SAD) is a seasonal pattern of recurrent major depressive episodes that most commonly occurs during autumn or winter and remits in spring. The prevalence of SAD ranges from 1.5% to 9%, depending on latitude. The predictable seasonal aspect of SAD provides a promising opportunity for prevention. This review - one of four reviews on efficacy and safety of interventions to prevent SAD - focuses on second-generation antidepressants (SGAs).

OBJECTIVES

To assess the efficacy and safety of second-generation antidepressants (in comparison with other SGAs, placebo, light therapy, melatonin or agomelatine, psychological therapies or lifestyle interventions) in preventing SAD and improving patient-centred outcomes among adults with a history of SAD.

SEARCH METHODS

A search of the Specialised Register of the Cochrane Depression, Anxiety and Neuorosis Review Group (CCDANCTR) included all years to 11 August 2015. The CCDANCTR contains reports of randomised controlled trials derived from EMBASE (1974 to date), MEDLINE (1950 to date), PsycINFO (1967 to date) and the Cochrane Central Register of Controlled Trials (CENTRAL). Furthermore, we searched the Cumulative Index to Nursing and Allied Health Literature, Web of Knowledge, The Cochrane Library and the Allied and Complementary Medicine Database (to 26 May 2014). We also conducted a grey literature search and handsearched the reference lists of included studies and pertinent review articles.

SELECTION CRITERIA

For efficacy, we included randomised controlled trials on adults with a history of winter-type SAD who were free of symptoms at the beginning of the study. For adverse events, we planned to include non-randomised studies. Eligible studies compared an SGA versus another SGA, placebo, light therapy, psychological therapy, melatonin, agomelatine or lifestyle changes. We also intended to compare SGAs in combination with any of the comparator interventions versus the same comparator intervention as monotherapy.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and full-text publications and assigned risk of bias ratings based on the Cochrane 'Risk of bias' tool. We resolved disagreements by consensus or by consultation with a third party. Two review authors independently extracted data and assessed risk of bias of included studies. When data were sufficient, we conducted random-effects (Mantel-Haenszel) meta-analyses. We assessed statistical heterogeneity by calculating the Chi(2) statistic and the Cochran Q. We used the I(2) statistic to estimate the magnitude of heterogeneity and examined potential sources of heterogeneity using sensitivity analysis or analysis of subgroups. We assessed publication bias by using funnel plots. However, given the small number of component studies in our meta-analyses, these tests have low sensitivity to detect publication bias. We rated the strength of the evidence using the system developed by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) Working Group.

MAIN RESULTS

We identified 2986 citations after de-duplication of search results and excluded 2895 records during title and abstract reviews. We assessed 91 full-text papers for inclusion in the review, of which four publications (on three RCTs) providing data from 1100 people met eligibility criteria for this review. All three RCTs had methodological limitations due to high attrition rates.Overall moderate-quality evidence indicates that bupropion XL is an efficacious intervention for prevention of recurrence of depressive episodes in patients with a history of SAD (risk ratio (RR) 0.56, 95% confidence interval (CI) 0.44 to 0.72; three RCTs, 1100 participants). However, bupropion XL leads to greater risk of headaches (moderate-quality evidence), insomnia and nausea (both low-quality evidence) when compared with placebo. Numbers needed to treat for additional beneficial outcomes (NNTBs) vary by baseline risks. For a population with a yearly recurrence rate of 30%, the NNTB is 8 (95% CI 6 to 12). For populations with yearly recurrence rates of 40% and 50%, NNTBs are 6 (95% CI 5 to 9) and 5 (95% CI 4 to 7), respectively.We could find no studies on other SGAs and no studies comparing SGAs with other interventions of interest such as light therapy, psychological therapies, melatonin or agomelatine.

AUTHORS' CONCLUSIONS

Available evidence indicates that bupropion XL is an effective intervention for prevention of recurrence of SAD. Nevertheless, even in a high-risk population, four of five patients will not benefit from preventive treatment with bupropion XL and will be at risk for harm. Clinicians need to discuss with patients advantages and disadvantages of preventive SGA treatment and might want to consider offering other potentially efficacious interventions, which might confer lower risk of adverse events. Given the lack of comparative evidence, the decision for or against initiating preventive treatment of SAD and the treatment selected should be strongly based on patient preferences.Future researchers need to assess the effectiveness and risk of harms of SGAs other than bupropion for prevention of SAD. Investigators also need to compare benefits and harms of pharmacological and non-pharmacological interventions.

Light therapy for preventing seasonal affective disorder

BACKGROUND

Seasonal affective disorder (SAD) is a seasonal pattern of recurrent major depressive episodes that most commonly occurs during autumn or winter and remits in spring. The prevalence of SAD ranges from 1.5% to 9%, depending on latitude. The predictable seasonal aspect of SAD provides a promising opportunity for prevention. This review - one of four reviews on efficacy and safety of interventions to prevent SAD - focuses on light therapy as a preventive intervention. Light therapy is a non-pharmacological treatment that exposes people to artificial light. Mode of delivery (e.g. visors, light boxes) and form of light (e.g. bright white light) vary.

OBJECTIVES

To assess the efficacy and safety of light therapy (in comparison with no treatment, other types of light therapy, second-generation antidepressants, melatonin, agomelatine, psychological therapies, lifestyle interventions and negative ion generators) in preventing SAD and improving patient-centred outcomes among adults with a history of SAD.

SEARCH METHODS

A search of the Specialised Register of the Cochrane Depression, Anxiety and Neuorosis Review Group (CCDANCTR) included all years to 11 August 2015. The CCDANCTR contains reports of relevant randomised controlled trials derived from EMBASE (1974 to date), MEDLINE (1950 to date), PsycINFO (1967 to date) and the Cochrane Central Register of Controlled Trails (CENTRAL). Furthermore, we searched the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Knowledge, The Cochrane Library and the Allied and Complementary Medicine Database (AMED) (to 26 May 2014). We also conducted a grey literature search and handsearched the reference lists of all included studies and pertinent review articles.

SELECTION CRITERIA

For efficacy, we included randomised controlled trials on adults with a history of winter-type SAD who were free of symptoms at the beginning of the study. For adverse events, we also intended to include non-randomised studies. We intended to include studies that compared any type of light therapy (e.g. bright white light, administered by visors or light boxes, infrared light, dawn stimulation) versus no treatment/placebo, second-generation antidepressants (SGAs), psychological therapies, melatonin, agomelatine, lifestyle changes, negative ion generators or another of the aforementioned light therapies. We also planned to include studies that looked at light therapy in combination with any comparator intervention and compared this with the same comparator intervention as monotherapy.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and full-text publications against the inclusion criteria. Two review authors independently abstracted data and assessed risk of bias of included studies.

MAIN RESULTS

We identified 2986 citations after de-duplication of search results. We excluded 2895 records during title and abstract review. We assessed 91 full-text papers for inclusion in the review, but only one study providing data from 46 people met our eligibility criteria. The included randomised controlled trial (RCT) had methodological limitations. We rated it as having high risk of performance and detection bias because of lack of blinding, and as having high risk of attrition bias because study authors did not report reasons for dropouts and did not integrate data from dropouts into the analysis.The included RCT compared preventive use of bright white light (2500 lux via visors), infrared light (0.18 lux via visors) and no light treatment. Overall, both forms of preventive light therapy reduced the incidence of SAD numerically compared with no light therapy. In all, 43% (6/14) of participants in the bright light group developed SAD, as well as 33% (5/15) in the infrared light group and 67% (6/9) in the non-treatment group. Bright light therapy reduced the risk of SAD incidence by 36%; however, the 95% confidence interval (CI) was very broad and included both possible effect sizes in favour of bright light therapy and those in favour of no light therapy (risk ratio (RR) 0.64, 95% CI 0.30 to 1.38). Infrared light reduced the risk of SAD by 50% compared with no light therapy, but in this case also the CI was too broad to allow precise estimations of effect size (RR 0.50, 95% CI 0.21 to 1.17). Comparison of both forms of preventive light therapy versus each other yielded similar rates of incidence of depressive episodes in both groups (RR 1.29, 95% CI 0.50 to 3.28). The quality of evidence for all outcomes was very low. Reasons for downgrading evidence quality included high risk of bias of the included study, imprecision and other limitations, such as self rating of outcomes, lack of checking of compliance throughout the study duration and insufficient reporting of participant characteristics.Investigators provided no information on adverse events. We could find no studies that compared light therapy versus other interventions of interest such as SGA, psychological therapies, melatonin or agomelatine.

AUTHORS' CONCLUSIONS

Evidence on light therapy as preventive treatment for patients with a history of SAD is limited. Methodological limitations and the small sample size of the only available study have precluded review author conclusions on effects of light therapy for SAD. Given that comparative evidence for light therapy versus other preventive options is limited, the decision for or against initiating preventive treatment of SAD and the treatment selected should be strongly based on patient preferences.

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.

Mental health and employment: The SAD story

This paper explores the relationship between health-related quality of life (HRQOL) measures and employment status in light of a constructed index related to Seasonal Affective Disorder that depends only on latitude and day of year. In models including demographic covariates and indicators for state, year, and quarter, more hours of darkness is associated with poorer HRQOL, which in turn is associated with a lower likelihood of employment. The relationships between the darkness index and HRQOL measures are stronger overall for women than for men. Inclusion of both the darkness index and the HRQOL measures in models of employment status determinants provides some evidence that the former operates through the latter in predicting a lower likelihood of employment. When specifying the darkness index as an instrument for HRQOL, each additional day of poor mental health per month leads to a 0.76 percentage point increase in the probability of unemployment among women.

[More than every tenth person have symptoms of seasonal affective disorder]

Seasonal affective disorder is a syndrome of classical depressive symptoms such as reduced energy, initiative and mood combined with atypical symptoms of increased appetite, weight and sleep duration. The symptoms recur each winter and disappear again in spring or early summer. The prevalence ranges from 1% to 10% in Scandinavian populations. Reduced light exposure, melatonergic and serotonergic disturbances are suggested pathogenetic factors. Light therapy offers convincing effect with minimal adverse effects and remains first-line treatment along with selective serotonin reuptake inhibitors.

Chronic sleep deprivation and seasonality: implications for the obesity epidemic

Sleep duration has progressively fallen over the last 100 years while obesity has increased in the past 30 years. Several studies have reported an association between chronic sleep deprivation and long-term weight gain. Increased energy intake due to sleep loss has been listed as the main mechanism. The consequences of chronic sleep deprivation on energy expenditure have not been fully explored. Sleep, body weight, mood and behavior are subjected to circannual changes. However, in our modern environment seasonal changes in light and ambient temperature are attenuated. Seasonality, defined as cyclic changes in mood and behavior, is a stable personality trait with a strong genetic component. We hypothesize that the attenuation in seasonal changes in the environment may produce negative consequences, especially in individuals more predisposed to seasonality, such as women. Seasonal affective disorder, a condition more common in women and characterized by depressed mood, hypersomnia, weight gain, and carbohydrate craving during the winter, represents an extreme example of seasonality. One of the postulated functions of sleep is energy preservation. Hibernation, a phenomenon characterized by decreased energy expenditure and changes in the state of arousal, may offer useful insight into the mechanisms behind energy preservation during sleep. The goals of this article are to: a) consider the contribution of changes in energy expenditure to the weight gain due to sleep loss; b) review the phenomena of seasonality, hibernation, and their neuroendocrine mechanisms as they relate to sleep, energy expenditure, and body weight regulation.

Circadian rhythms and depression

BACKGROUND

Depression is a common disorder in primary care. Disruptions to the circadian rhythms associated with depression have received little attention yet offer new and exciting approaches to treatment.

OBJECTIVE

This article discusses circadian rhythms and the disruption to them associated with depression, and reviews nonpharmaceutical and pharmaceutical interventions to shift circadian rhythms.

DISCUSSION

Features of depression suggestive of a disturbance to circadian rhythms include early morning waking, diurnal mood changes, changes in sleep architecture, changes in timing of the temperature nadir, and peak cortisol levels. Interpersonal social rhythm therapy involves learning to manage interpersonal relationships more effectively and stabilisation of social cues, such as including sleep and wake times, meal times, and timing of social contact. Bright light therapy is used to treat seasonal affective disorders. Agomelatine is an antidepressant that works in a novel way by targeting melatonergic receptors.

[Diagnostic features, epidemiology, and pathophysiology of seasonal affective disorder]

Seasonal Affective Disorder (SAD) is characterized by patterns of major depressive episodes that occur and remit with the change of seasons. Two seasonal patterns have been identified: summer-type depression with typical depressive signs and symptoms, and winter-type depression with atypical features of depression. In the subsyndromal form of SAD (S-SAD) symptoms are milder, although vegetative symptoms are clinically significant. SAD needs to be differentiated from atypical depression, cyclothymic disorder, and dysthymia or chronic MDD which may be characterized by a winter worsening of symptoms. Full remission of symptoms must occur after the passing of the season for the disorder to merit the diagnosis of SAD. The mean prevalence of SAD in the temperate zone is 3 to 10%, while that of S-SAD is 6 to 20%. In Hungarian general population the occurrence of SAD is 4.6%, and S-SAD is 7.2%. The pathophysiology of SAD seems to be heterogeneous, studies suggest abnormal circadian rhythm and neurotransmitter function (phase shift hypothesis, role of serotonin, dopamin and norepinephrine). Genetic studies focusing on candidate genes involve 5-HTR2A, 5-HTR2C, DRD4, G protein, and clock-related genes.

Seasonal affective disorder and latitude of living

AIM

Since the importance of latitude of living for the prevalence of Seasonal Affective Disorder (SAD) is unclear, the study aims to test the latitude hypothesis by comparing SAD in two rather similar groups of students living at latitudes far apart.

METHODS

Two groups of students, 199 in Tromsø, Norway (690 N) and 188 in Ferrara, Italy (440 N) were asked to fill in the Seasonal Pattern Assessment Questionnaire.

RESULTS

Global Seasonality score (GS-score) was significantly higher in Italian than in Norwegian students, in females and in students with sleeping-problems. Norwegian students had significantly higher SAD prevalence in winter and in spring. Most people in both countries felt worst in October and November, and the prevalence of Autumn SAD was not significantly different between the two countries.

CONCLUSIONS

The hypothesis that SAD is linked to amount of environmental light and latitude of living was not supported.

[Sleep disturbances--cause or result of depression]

Sleep disturbances are a very sensitive indicator, which allows identifying various psychic illnesses, especially depression. Irrelevant of the very nature of sleep disturbances, their presence can tell us about the onset of depression or its ending. The mechanism of sleep disturbances seems to be tightly bound with the physiology of depression. Besides physiological, neuroendocrine and behavioural parameters, which are altered in depression, sleep disturbances play a more exposed role in the recent years. This has been brought about by a better identification of daily rhythm disorders in major depressive disorder (MDD), bipolar disorder (BD) or seasonal affective disorder (SAD) and the discovery of a correlation between lowered mood and changes in the rhythm and level of melatonine secretion. Also, the discovery of the substance which is supposedly correcting the disordered circadian rhythm (agomelatine), means a step forward in the search for an effective treatment of depression. It is worthy to look closer into its regulatory effect on the disordered circadian rhythm, which is not only to give an antidepressive effect, but in a visible improvement of sleep architecture and functioning during the day.

Cultural variation in seasonal depression: cross-national differences in winter versus summer patterns of seasonal affective disorder

BACKGROUND

Research suggests that two dimensions of national culture, individualism-collectivism and power distance, predict affective responses to the seasonally varying levels of ambient sunlight that may underlie regular cycles of mood and behavior in Seasonal Affective Disorder (SAD). Specifically, negative affect is predicted by the diminished sunlight of fall-winter in countries higher in individualism and lower in power distance, and by the increased sunlight of spring-summer in countries lower in individualism and higher in power distance. This study tests whether individualism correlates positively, and power distance negatively, with the frequency of winter-SAD relative to that of summer-SAD.

METHOD

A search for studies reporting frequencies of both winter-SAD and summer-SAD identified 55 samples encompassing 18 countries and 38,408 participants, including 1931 with SAD.

RESULTS

The frequency of winter-SAD, relative to that of summer-SAD, correlated positively with individualism (r=.67, p=.001) and negatively with power distance (r=-.72, p=.0001). Countries in which winter-SAD was more common than summer-SAD were significantly more individualistic and less power-distant than countries in which summer-SAD was more common than winter-SAD. Results survived various tests of threats to validity.

LIMITATIONS

The study is limited by the quantity, quality, diversity, and representativeness of the research under review and by its correlational design.

CONCLUSIONS

Individualism and power distance are strongly related to the relative prevalence of winter-SAD and summer-SAD. Culture may play an important but previously overlooked role in the etiology of SAD.

Dates of birth and seasonal changes in well-being among 4904 subjects completing the seasonal pattern assessment questionnaire

BACKGROUND

Abnormal distributions of birthdates, suggesting intrauterine aetiological factors, have been found in several psychiatric disorders, including one study of out-patients with Seasonal Affective Disorder (S.A.D.). We investigated birthdate distribution in relation to seasonal changes in well-being among a cohort who had completed the Seasonal Pattern Assessment Questionnaire (SPAQ).

METHOD

A sample of 4904 subjects, aged 16 to 64, completed the SPAQ. 476 were cases of S.A.D. on the SPAQ and 580 were cases of sub-syndromal S.A.D. (S-S.A.D.). 92 were interview confirmed cases of S.A.D. Months and dates of birth were compared between S.A.D. cases and all others, between S.A.D. and S-S.A.D. cases combined and all others, and between interview confirmed cases and all others. Seasonality, as measured through seasonal fluctuations in well-being on the Global Seasonality Scores (GSS) of the SPAQ, was compared for all subjects by month and season of birth.

RESULTS

There was no evidence of an atypical pattern of birthdates for subjects fulfilling criteria for S.A.D., for the combined S.A.D./S-S.A.D. group or for interview confirmed cases. There was also no relationship between seasonality on the GSS and month or season of birth.

LIMITATIONS

Diagnoses of S.A.D. made by SPAQ criteria are likely to be overinclusive.

CONCLUSION

Our findings differ from studies of patients with more severe mood disorders, including psychiatric out-patients with S.A.D. The lack of association between seasonality and birthdates in our study adds credence to the view that the aetiology of S.A.D. relates to separable factors predisposing to affective disorders and to seasonality.

Season of birth modulates mood seasonality in humans

We investigate whether mood seasonality is modulated by season of birth. A sample of 1682 university students were administered the Seasonal Pattern Assessment Questionnaire. We found that subjects born during spring or summer months had significantly higher Global Seasonality scores than those born during autumn or winter months.

Season of birth in siblings of patients with seasonal affective disorder. A test of the parental conception habits hypothesis

Recently we have published a report on seasonally varying birth rates in 553 patients with seasonal affective disorder (SAD). The present study is aimed to test the hypothesis of an idiosyncratic seasonal conception pattern of the parents of these patients to explain this phenomenon. We conducted a telephone interview with the patients to obtain information on the birth data of their siblings. Using the method of chart review to acquire information on the family history of our patients, we excluded those siblings with psychiatric disorders. We first compared the birth months and the quarters of birth of 435 healthy siblings with the general population. Secondly, we compared the birth distribution of the index SAD patients with that of their siblings. There was a significant deviation between the birth distribution of the siblings and the general population calculated on a monthly basis (p = 0.044). When comparing quarters we found less births than expected in the first (-14.1%) and fourth quarter of the year (-15.1%) and an excess of births in the second (+7.7%) and third quarter (+21.1%; p = 0.018). There were no significant differences between the group of SAD patients and their siblings regarding their birth patterns as calculated by months (p = 0.848) or quarters (p = 0.320). Our study provides support for the hypothesis of specific parental conception habits underlying the birth seasonality in SAD. Further research could be conducted in non-seasonal depression as there is still a lack of studies on seasonality of birth in affective disorders.

Is there seasonal variation in risk of Parkinson's disease?

Recent studies suggest that, for many adult-onset neurological diseases, persons born at a certain time of year are at higher risk of the disease. Small-scale studies have suggested that persons born in the spring may be at higher risk of developing Parkinson's disease (PD) late in life. There have also been suggestions that there are clusters of PD birth dates in the years of major influenza pandemics. To determine whether there is any seasonal variation in the birth dates of PD patients, we examined birth dates of 8,168 PD patients collected from subspecialty movement disorder clinics across Canada. Patterns of seasonality of birth were examined and compared with the general Canadian population. In addition, we compared counts of patients born in the years of major influenza pandemics with the number born in the surrounding years. We found no evidence of systematic seasonal variation in PD incidence by birth date, or of clustering of birth dates during influenza pandemic years in PD patients.

Mood-worsening with high-pollen-counts and seasonality: a preliminary report

BACKGROUND

Because aeroallergens produce inflammation in the respiratory airways, and inflammation triggers depression in vulnerable individuals, we hypothesized that mood sensitivity to pollen, the most seasonal aeroallergen, will be associated with a greater seasonality of mood. Since pollen is absent during winter, we specifically predicted that mood sensitivity to tree pollen will predict non-winter SAD but not winter SAD.

METHODS

A convenience sample of African and African American college students who lived in the Washington DC metropolitan area for at least the past 3 years completed the Seasonal Pattern Assessment Questionnaire (SPAQ), from which the Global Seasonality Score (GSS) was calculated, a diagnosis of cumulative SAD (syndromal or subsyndromal SAD) was derived, a seasonal pattern (winter vs non-winter) identified, and self-reported mood changes during high pollen counts obtained. A Mann-Whitney test was used to compare GSS between participants with vs without mood worsening during high pollen counts. The capability of mood worsening with high pollen counts, gender, ethnicity, and age to predict non-winter SAD was analyzed with logistic regressions.

RESULTS

GSS was greater (z=5.232, p<0.001) in those who reported mood worsening with high pollen counts. Mood sensitivity to pollen predicted non-winter SAD (p=0.017), but not winter SAD.

LIMITATIONS

The SPAQ is not a definitive tool to assess seasonality, and self-reported mood worsening with high pollen counts relies on recollection. No direct measures of depression scores or pollen counts were collected. The non-winter SAD concept has not been previously established.

CONCLUSIONS

Our study, which should be considered preliminary in light of its limitations, suggests that self-reported mood-worsening with high pollen count is associated with a greater seasonality of mood, and predicts SAD of non-winter type.

Seasonal variations in mood and behavior in Romanian postgraduate students

To our knowledge, this paper is the first to estimate seasonality of mood in a predominantly Caucasian sample, living in areas with hot summers and a relative unavailability of air conditioning. As a summer pattern of seasonal depression was previously associated with a vulnerability to heat exposure, we hypothesized that those with access to air conditioners would have a lower rate of summer seasonal affective disorder (SAD) compared to those without air conditioning. A convenience sample of 476 Romanian postgraduate students completed the Seasonal Pattern Assessment Questionnaire (SPAQ), which was used to calculate a global seasonality score (GSS) and to estimate the rates of winter- and summer-type SAD. The ratio of summer- vs. winter-type SAD was compared using multinomial probability distribution tests. We also compared the ratio of summer SAD in individuals with vs. without air conditioners. Winter SAD and winter subsyndromal SAD (S-SAD) were significantly more prevalent than summer SAD and summer S-SAD. Those with access to air conditioners had a higher, rather than a lower, rate of summer SAD. Our results are consistent with prior studies that reported a lower prevalence of summer than winter SAD in Caucasian populations. Finding an increased rate of summer SAD in the minority of those with access to air conditioners was surprising and deserves replication.

Serum lipid levels in seasonal affective disorder

Previous research has assessed the relationship between blood lipid levels and depression with contradictory results. Several studies have linked low cholesterol levels with impulsive, aggressive and suicidal behaviours. The aim of this pilot study was to examine serum lipids in a sample of patients suffering from seasonal affective disorder (SAD). We conducted a retrospective analysis of data on total serum cholesterol and serum triglycerides in 39 SAD patients and 40 non-seasonally depressed or schizophrenic control subjects. Study subjects had to be free of psychotropic drugs for at least 2 weeks. Analysis of covariance (ANCOVA) was performed to assess group differences. After adjustment for significant covariates SAD patients had significantly lower total cholesterol levels (5.21 +/- 1.14 mmol/l) than control subjects (5.94 +/- 1.11 mmol/l; p = 0.013). Moreover, hypercholesterolemia (total cholesterol > 5.20 mmol/l) was significantly less frequent in the SAD group (46.2%) than in the control group (75.0%; p = 0.012). Total serum triglycerides did not differ significantly between SAD patients (1.54 +/- 1.07 mmol/l) and controls (1.56 +/- 0.96 mmol/l; p = 0.126). The results of this study support the idea that low cholesterol levels may be of pathogenetic importance in SAD. Further study in larger clinical samples is warranted to clarify our findings.

Mood sensitivity to seasonal changes in African college students living in the greater Washington D.C. metropolitan area

The purpose of this study was to estimate the degree of seasonality and prevalence of winter- and summer-type seasonal affective disorder (SAD) in African immigrant college students in comparison with African American peers. A convenience sample of 246 African immigrants and 599 African Americans studying in Washington, D.C. completed the Seasonal Pattern Assessment Questionnaire (SPAQ), which was used to calculate a global seasonality score (GSS) and to estimate the prevalence of winter- and summer-type SAD. Degree of seasonality was related to a complex interaction between having general awareness of SAD, ethnicity, and gender. A greater percentage of African students reported experiencing a problem with seasonal changes relative to African American students, and had summer SAD, but the groups did not differ on GSS and winter SAD. African students reported more difficulties with seasonal changes than their African American peers, which could represent a manifestation of incomplete acclimatization to a higher latitude and temperate climate. As Africans also had a greater rate of summer SAD, this argues against acclimatization to heat.

CLOCK gene 3111C/T polymorphism is not associated with seasonal variations in mood and behavior in Korean college students

The present study tested the potential association between the 3111C/T polymorphism of the CLOCK gene and seasonal variations in mood and behavior. A total of 297 Korean college students were genotyped for the CLOCK polymorphism and the seasonal variation was evaluated using the Seasonal Pattern Assessment Questionnaire (SPAQ). The seasonality scores were not different between CLOCK gene variants (P > 0.05). Comparison between seasonals (syndromal plus subsyndromal seasonal affective disorder according to SPAQ) and non-seasonals found no significant difference in frequencies of genotypes (P > 0.05). These findings suggest that the CLOCK polymorphism does not play a major role in susceptibility to seasonal variations in a Korean population.

Mood seasonality: a cross-sectional study of subjects aged between 10 and 25 years

BACKGROUND

Most of the earlier studies on mood seasonality were conducted in adults and there are few available data on children and adolescents. In two cross sectional surveys, we examined the role of age and gender on seasonal sensitivity in subjects aged 10 to 25 years.

METHODS

In survey one, the Seasonal Pattern Assessment Questionnaire for Children and Adolescents (SPAQ-CA) was administered to 1709 subjects (845 females and 864 males) from 10 to 17 years. In survey two, the Seasonal Pattern Assessment Questionnaire (SPAQ) was administered to 1867 subjects (1061 females and 806 males) from 18 to 25 years.

RESULTS

Only in survey one was a significant positive correlation found between age and Global Seasonality Score (GSS) (r=.29; p<.00001). Significant gender differences were found at age 14 years and above in survey one, and at all ages in survey two.

CONCLUSIONS

The results support the hypothesis that seasonal sensitivity is higher in female subjects.

Seasonal affective disorder

Patients with seasonal affective disorder have episodes of major depression that tend to recur during specific times of the year, usually in winter. Like major depression, seasonal affective disorder probably is underdiagnosed in primary care settings. Although several screening instruments are available, such screening is unlikely to lead to improved outcomes without personalized and detailed attention to individual symptoms. Physicians should be aware of comorbid factors that could signal a need for further assessment. Specifically, some emerging evidence suggests that seasonal affective disorder may be associated with alcoholism and attention-deficit/hyperactivity disorder. Seasonal affective disorder often can be treated with light therapy, which appears to have a low risk of adverse effects. Light therapy is more effective if administered in the morning. It remains unclear whether light is equivalent to drug therapy, whether drug therapy can augment the effects of light therapy, or whether cognitive behavior therapy is a better treatment choice.

The association between seasonal and premenstrual symptoms is continuous and is not fully accounted for by depressive symptoms

Seasonal affective disorder (SAD) frequently co-occurs with premenstrual dysphoric disorder. Explanations of this comorbidity highlighting the cyclical nature of female sex hormones imply that seasonal and premenstrual symptoms should correlate positively even in nonclinical samples. In a sample of 91 female college students, we found a sizable positive correlation (r = .45; p < 0.001) between seasonal and premenstrual symptoms. This relation held up even in a subsample selected on the basis of not qualifying for SAD or subsyndromal SAD on a screening measure. Although the correlation was reduced when depressive symptom severity was statistically controlled, it remained positive and significant. Future research testing possible explanations of the co-occurrence of seasonal and premenstrual symptoms should incorporate the full range of severity on symptom variables, treating them as continua rather than solely as binary categories.

An open trial of light therapy in adult attention-deficit/hyperactivity disorder

OBJECTIVE

In adults with attention-deficit/ hyperactivity disorder (ADHD), a delayed sleep/ activity rhythm and/or seasonal mood symptoms may contribute significantly to core pathology and disability. This study examined whether a chronobiologically based treatment, i.e., morning bright light therapy (LT), might have utility as an adjunctive treatment for adult ADHD in the fall/ winter period.

METHOD

Twenty-nine adults with DSM-IV ADHD were administered a standard 3-week open trial of LT during the fall or winter months. Primary outcome measures included percentage reduction on the Brown Adult ADD Scale and the Conners' Adult ADHD Scale. Secondary measures were decrease in depression scores according to the Structured Interview Guide for the Hamilton Depression Rating Scale, Seasonal Affective Disorder version; improvements on various neuropsychological tests; and shift toward an earlier circadian preference as measured by the Horne-Ostberg Morningness-Eveningness questionnaire. Regression analyses determined which variables at baseline best predicted improvement on a given outcome measure and which variables changed in parallel with one another. The study was conducted from November 2003 through February 2004.

RESULTS

Morning bright light therapy was associated with a significant decrease in both subjective and objective measures of core ADHD pathology, improved mood symptoms, and a significant phase advance in circadian preference. Multiple regression showed that the shift toward an earlier circadian preference with LT was the strongest predictor of improvement on both subjective and objective ADHD measures. Neither baseline global seasonality scores nor baseline depression scores strongly predicted LT effects on most measures of ADHD.

CONCLUSION

These findings suggest that during the fall/winter period, LT may be a useful adjunct in many adults with ADHD. Strikingly, the strongest correlate of improvement in core ADHD pathology was a phase advance in circadian preference rather than alleviation of comorbid seasonal affective disorder, suggesting important clinical benefits of LT beyond the treatment of seasonal affective disorder.

Sensitivity to seasonal changes in panic disorder patients

It has been suggested that symptoms of panic disorder may be significantly affected by seasonal factors including weather changes, although few studies have explored the issue. The purpose of the present paper was to investigate clinical data to examine sensitivity of panic disorder patients to seasonal changes and seasonal fluctuation of panic disorder symptoms. A self-rating questionnaire consisting of the Seasonal Pattern Assessment Questionnaire (SPAQ) and additional self-rating questions were analyzed in 146 Japanese patients (50 male, 96 female) with panic disorder (DSM-IV) at an outpatient clinic for anxiety disorder. The average of the Global Seasonality Scores (GSS) was 12.5+/-4.7 and 25.3% of the patients were suggested to suffer from seasonal affective disorder, according to the GSS. Frequency of the panic attack was found to fluctuate seasonally, with peaks in August and December (P=0.005 and 0.01, chi2 test). The present results indicate that panic disorder patients may be more sensitive to seasonal and meteorological factors than the general population and become more fragile in a specific season or months. This might assist in the development of preventive measures for the frequent recurrence of symptoms in panic disorder.

Seasonality of mood disorders in adults with lifetime attention-deficit/hyperactivity disorder (ADHD)

BACKGROUND

The objective of this study was to estimate the prevalence of Seasonal Affective Disorder (SAD) in adults with lifetime Attention-Deficit/Hyperactivity Disorder (ADHD).

METHOD

Patients eligible for this study had lifetime impairing symptoms of ADHD and a current and/or past co-morbid mood disorder according to their medical record. The Seasonal Pattern Assessment Questionnaire (SPAQ) was administered by a telephone interview to assess seasonality.

RESULTS

The overall rate of SAD in this clinical population of adults with ADHD was estimated at 27%. Females were more at risk to develop SAD than men.

LIMITATIONS

The SPAQ is a screening, not a diagnostic instrument.

CONCLUSIONS

SAD symptoms are frequently comorbid with ADHD in adults. These results have clinical relevance for the recognition and treatment of SAD with bright light therapy in adults with ADHD.

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.

High prevalence of self-reported depressive mood during the winter season among Swedish senior high school students

OBJECTIVE

There are few studies regarding the prevalence of seasonal variation in mood among children and adolescents. The main objective of this study was to estimate the prevalence of self-reported depressive mood during the winter season among Swedish adolescents and to investigate gender differences. Another aim was to analyze the factor structure and internal consistency of the Kiddie SPAQ (K-SPAQ), a pediatric version of the Seasonal Pattern Questionnaire (SPAQ).

METHOD

All students 17 to 18 years old, registered in the second year of senior high school in Falun, a district in central Sweden, were screened with the K-SPAQ in January 2003 (response rate 87.3%, n = 756).

RESULTS

The prevalence of self-reported depressive mood during the winter season was estimated at 20.1% (n = 151/751) and was higher among girls (25.5%) than boys (13.8%). Approximately 8% reported more severe depressive symptoms. Depressive mood during the summer was rare (0.1%, n = 1/751). Factor analysis of the General Seasonal Score items in the K-SPAQ revealed a two-factor structure. A Cronbach's alpha of 0.87 demonstrated a good internal consistency.

CONCLUSIONS

Depressive symptoms during autumn and winter were common among Swedish senior high school students, especially among girls. This is probably an underdiagnosed condition among adolescents that ought to receive more attention from the health and school authorities.

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.

Psychic and somatic anxiety differentially predict response to light therapy in women with seasonal affective disorder

OBJECTIVE

To examine whether psychic and/or somatic anxiety predict responsiveness to light therapy in women with winter Seasonal Affective Disorder (SAD).

DESIGN

Eighty-one women with SAD were administered a standard 10-day trial of light therapy administered for one-half hour in the early morning. Using a multiple regression model, baseline somatic and psychic anxiety item scores were used to predict percentage change scores on the 29-item SIGH-SAD post treatment. Baseline scores for weight gain, hypersomnia and the total SIGH-SAD were also included as predictor variables.

RESULTS

The regression model was highly significant (F=4.63, df=5,75; p=.001; model R(2)=.236), with both psychic anxiety and somatic anxiety contributing significantly to the model. Consistent with prior work using anti-depressant medication in non-seasonal depression, psychic anxiety was positively correlated with outcome, while somatic anxiety negatively predicted outcome.

CONCLUSIONS

In SAD, psychic and somatic anxiety scores at baseline appear to be independent and opposite predictors of light therapy response. These effects were independent of baseline scores for weight gain and hypersomnia, two previously established predictors of response to light. These findings may be an important consideration in the design and interpretation of light therapy studies of SAD.

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.

Are seasonality of mood and eveningness closely associated?

It has been suggested that being an "evening type" might enhance susceptibility to non-seasonal and seasonal affective disorders (SAD). In a survey and a prospective study, we examine the relationship between mood seasonality and circadian typology. In the survey study, the Morningness-Eveningness Questionnaire (MEQ) and the Seasonal Pattern Assessment Questionnaire (SPAQ) were administered to 1715 university students from Spain and Italy. In the prospective study, 18 subjects, selected from the Italian sample, self-assessed their mood monthly for over a year. A slight but significant negative correlation between the MEQ score and the Global Seasonality Score was found in the survey study, with a significantly higher incidence of evening versus morning types among the students with seasonal depression. These results were not replicated when the Spanish sample was analysed separately. In the prospective study, evening types did not present a higher annual range of mood variations than morning types. Caution should be exercised in ascribing eveningness as a risk factor in SAD since other underestimated factors, including social-cultural conditions, might be involved in the pathogenesis of mood seasonality.

Seasonal affective disorder: a vestigial evolutionary advantage?

The typical symptoms of recurrent winter depression include lowered mood, lethargy, hypersomnia, social withdrawal, decreased libido, increased appetite and weight gain. Mild hypomania often occurs in spring and summer. It is argued that this pattern of attenuated hibernation constituted an adaptive evolutionary mechanism which enhanced the likelihood of reproductive success, most notably for females, among populations living at temperate latitudes. Women were more likely to become pregnant in the summer and thus to give birth at a time of year when their babies had a higher chance of survival. Winter depression symptoms also promoted healthier pregnancies and gave rise to enhanced female-male pair-bonding which improved the survival chances of both mothers and babies. Hypomania in spring and summer also served to increase the likelihood of procreation at the optimal time of year. In the modern era, it is probable that recurrent winter depression is becoming a reproductive disadvantage.

Seasonal mood variation in the elderly: the Leiden 85-plus study

BACKGROUND

The influence of seasonal changes on mood and behaviour is called seasonality. The prevalence of seasonality in elderly subjects is unknown.

AIM

To investigate the seasonality pattern in mood and behaviour at old age.

METHODS

All subjects from the Leiden 85-plus Study with an MMSE score of 19 or more were assessed for depressive feelings at age 85 and yearly thereafter. The influence of time of the year, duration of sunlight, daylight, and rain on the prevalence of depressive symptoms was assessed using linear mixed models for repeated measurements.

RESULTS

There was no significant seasonal pattern in the data (p=0.44). Within each of the four years of observation (85, 86, 87 and 88 years) and all years combined, there was also no significant association between the one-month cumulation of duration of sunlight, daylight, or rain and the score on the GDS (all p-values >0.05). The results of either the one week or three-month accumulation of sunlight, daylight, or rain were comparable to the one-month results.

CONCLUSIONS

Estimates of prevalence of seasonality reported in the literature might be overestimated or a remarkable difference between young and old subjects exists.