Mood and behaviour problems associated with seasonal changes in Britain and Ireland

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

BACKGROUND

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

METHODS

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

The influence of several changes in atmospheric states over semi-arid areas on the incidence of mental health disorders

The incidence of suicide attempts [Deliberate Self Harm (DSH); ICD-10: X60-X84] and psychotic attacks (PsA; ICD-10, F20-F29) in association with atmospheric states, typical for areas close to big deserts, was analyzed. A retrospective study is based on the 4,325 cases of DSH and PsA registered in the Mental Health Center (MHC) of Ben-Gurion University (Be'er-Sheva, Israel) during 2001-2003. Pearson and Spearman test correlations were used; the statistical significance was tested at p < 0.1. The influence of temperature and humidity on suicide attempts (N(SU)) and psychotic attacks (N(PS)) was weakly pronounced (p > 0.1). Correlation coefficients between N(SU) and N(PS) and speed WS of westerly wind reaches 0.3 (p < 0.05), while their dependence on easterly WS was weaker (p > 0.09). Variations in easterly wind direction WD influence N(SU) and N(PS) values (p < 0.04), but no corresponding correlation with westerly winds was found (p > 0.3). Obviously ,in transition areas located between different regions ,the main role of air streams in meteorological-biological impact can scarcely be exaggerated. An unstable balance in the internal state of a weather-sensitive person is disturbed when the atmospheric state is changed by specific desert winds, which can provoke significant perturbations in meteorological parameters. Results indicate the importance of wind direction, defining mainly the atmospheric situation in semi-arid areas: changes in direction of the easterly wind influence N(SU) and N(PS), while changes in WS are important for mental health under westerly air streams. Obviously, N(SU) and N(PS) are more affected by the disturbance of weather from its normal state, for a given season, to which the local population is accustomed, than by absolute values of meteorological parameters.

Seasonal vegetative and affective symptoms in the Finnish general population: testing the dual vulnerability and latitude effect hypotheses

BACKGROUND

Prior studies identified a seasonal pattern in symptoms of depression in clinical and population-based samples. The aims of our study were to estimate the prevalence rates of routine seasonal variations in mood and behavior and of current depressive symptoms in the Finnish general population over 30 years, and to find differences, if any, between the northern and southern regions of residence.

METHODS

5749 participants aged 30-97 (3156 women and 2593 men) were interviewed face to face and attended a health status examination. We included the modified Seasonal Pattern Assessment Questionnaire and the modified Beck Depression Inventory (BDI) for the analysis.

RESULTS

85% of the sample, representative of a general population, had seasonal variations in mood and behavior; 9% of the sample scored high on both scales, thus having the routine seasonal variations together with a current self-report of winter depression. Scoring high on the former scale yielded the odds ratio of 3.12 for scoring high on the BDI. Neither the global seasonality score nor the BDI sum score was associated with latitude. No significant differences in affective symptoms were found by the latitude. The seasonal variation in sleep duration (P<0.001) was more prevalent in the northern regions.

LIMITATIONS

The seasonal variations were assessed with a self-report only.

CONCLUSIONS

A seasonal pattern in mood and behaviors was detected in a general population. Implications of our findings include the assessment of the seasonal variations as a risk factor of depressive illness.

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.