Seasonal affective disorder and seasonal changes in weight and sleep duration are inversely associated with plasma adiponectin levels.

Overlapping pathways between mood and metabolic regulation have increasingly been reported. Although impaired regulation of adiponectin, a major metabolism-regulating hormone, has been implicated in major depressive disorder, its role in seasonal changes in mood and seasonal affective disorder-winter type (SAD), a disorder characterized by onset of mood impairment and metabolic dysregulation (e.g.

Heritability of plasma neopterin levels in the Old Order Amish.

Background: We examined the heritability of neopterin, a biomarker for cell-mediated immunity and oxidative stress, and potentially for psychiatric disorders, in the Old Order Amish.

Methods: Plasma neopterin levels were determined in 2015 Old Order Amish adults. Quantitative genetic procedures were used to estimate heritability of neopterin.

In psychiatrically healthy individuals, overweight women but not men have lower tryptophan levels.

Gender differences in tryptophan (TRP) breakdown in obese individuals have been previously reported. This could be both contributory to, as well as a consequence of, gender differences in mood changes among obese people. To exclude the potential effect of depression on TRP breakdown and its levels in obesity, we replicated analyses in psychiatrically healthy individuals.

Seasonality shows evidence for polygenic architecture and genetic correlation with schizophrenia and bipolar disorder.

Objective: To test common genetic variants for association with seasonality (seasonal changes in mood and behavior) and to investigate whether there are shared genetic risk factors between psychiatric disorders and seasonality.

Method: Genome-wide association studies (GWASs) were conducted in Australian (between 1988 and 1990 and between 2010 and 2013) and Amish (between May 2010 and December 2011) samples in whom the Seasonal Pattern Assessment Questionnaire (SPAQ) had been administered, and the results were meta-analyzed in a total sample of 4,156 individuals. Genetic risk scores based on results from prior large GWAS studies of bipolar disorder, major depressive disorder (MDD), and schizophrenia were calculated to test for overlap in risk between psychiatric disorders and seasonality.

Chronotype and seasonality: morningness is associated with lower seasonal mood and behavior changes in the Old Order Amish.

Background: Several studies documented that lower scores on the Morningness-Eveningness Questionnaire (MEQ) are associated with a higher global seasonality of mood (GSS). As for the Modern Man artificial lighting predominantly extends evening activity and exposure to light, and as evening bright light phase is known to delay circadian rhythms, this chronic exposure could potentially lead to both lower Morningness as well as higher GSS. The aim of the study was to investigate if the MEQ-GSS relationship holds in the Old Order Amish of Lancaster County, PA, a population that does not use network electrical light.

Seasonality patterns of mood and behavior in the Old Order Amish.

Background: Although humans have become partially isolated from physical seasonal environmental changes through artificial lighting and temperature control, seasonal changes in mood and behavior have been described across hemispheres, continents, ethnicities and occupations. The Old Order Amish are more exposed than the general population to environmental seasonal changes both occupationally as well as through their limited use of electric light in the winter and air conditioning in the summer; yet, their seasonal changes in mood and behavior have not been previously studied.

Methods: The aim of this study was to analyze seasonal patterns in mood and behavior in the Old Order Amish of Lancaster County, Pennsylvania, who returned completed Seasonal Pattern Assessment Questionnaires (SPAQ).

Test-retest reliability of the Seasonal Pattern Assessment Questionnaire in Old Order Amish.

Background: Research on test-retest reliability of the Season Pattern Assessment Questionnaire (SPAQ) is sparse, and to date, has not been done with subgroups such as the Old Order Amish.

Methods: We examined the test-retest reliability of the SPAQ in a sample of Old Order Amish. A total of 68 Old Order Amish participants completed the SPAQ twice, with 4 months between administrations.

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.