module (PHQ-9) and defined as severity of depressive symptoms (PHQ-9 score, range 0-27 points) and elevated depressive symptoms (PHQ-9 score >= 10 points) were analysed using multivariable linear and logistic regression adjusted for sociodemographic, biological and lifestyle factors. Analyses were stratified by summertime (May to October) and wintertime (November to April) because of evidence for interaction with season (p=<0.01). 3 ResultsIn crude analyses, vitamin D status was inversely associated with both depression outcomes in summertime but not in wintertime. After adjustment for potential confounders, a significant association with severity of depressive symptoms remained in summer, with 0.73 point lower PHQ-9 scores in the highest versus lowest quartile. The association between 25(OH)D quartiles and elevated depressive symptoms in summertime was less strong and no longer significant in fully adjusted models. LimitationsParticipants with severe depression may be underrepresented in DEGS1. Residual confounding cannot be excluded. Conclusion25(OH)D serum levels were inversely associated with current depressive symptoms in summer but not in wintertime. The fact that the association is stronger in summertime suggests that vitamin D deficiency may be a consequence rather than a cause of depression.

MRI enables us to define characteristic morphological changes of the brain in patients with extrapyramidal movement disorders. Early recognition of these findings avoids misdiagnoses in patients who are difficult to diagnose.