Background: Chronotype reflects an individual's optimal daily timing of sleep, activity, and cognitive performance. Previous, cross-sectional, studies have suggested an age effect on chronotype... Show moreBackground: Chronotype reflects an individual's optimal daily timing of sleep, activity, and cognitive performance. Previous, cross-sectional, studies have suggested an age effect on chronotype with later chronotypes in adolescents and earlier chronotypes in children and elderly. Additionally, later chronotypes have been associated with more depressive symptoms. Few studies have been able to study longitudinal associations between chronotype and age, while adjusting for depressive symptoms. Methods: Chronotype was assessed twice with the Munich Chronotype Questionnaire 7 years apart in the Netherlands Study of Depression and Anxiety (T1: N = 1842, mean age (SD): 42.63 years (12.66)) and T2: N = 1829, mean age (SD) 50.67 (13.11)). The longitudinal association between change in age and change in chronotype was tested using a generalized estimated equation analysis adjusted for covariates (including level of depressive symptoms). Using age-bins of 5 years (age at T2), change in chronotype between T1 and T2 was analyzed with Linear Mixed Models. Results: We found a change towards an earlier chronotype with higher age (B (95% CI): -0.011 (-0.014-0.008), p < 0.001). For the age-bins, the difference in chronotype was significant for the 25-29 years age-bin. Limitations: The sample did not include individuals younger than 19 years or older than 68 years. Conclusions: In the whole sample chronotype changed towards becoming more morning-type over a period of 7 years, but this change was only significant for those aged 25-29 years. The study was performed in a large naturalistic cohort study with a wide age-range, including patients with a diagnosis of depressive and anxiety disorder and healthy controls. Show less
Background: Chronotype reflects an individual's optimal daily timing of sleep, activity, and cognitive performance. Previous, cross-sectional, studies have suggested an age effect on chronotype... Show moreBackground: Chronotype reflects an individual's optimal daily timing of sleep, activity, and cognitive performance. Previous, cross-sectional, studies have suggested an age effect on chronotype with later chronotypes in adolescents and earlier chronotypes in children and elderly. Additionally, later chronotypes have been associated with more depressive symptoms. Few studies have been able to study longitudinal associations between chronotype and age, while adjusting for depressive symptoms. Methods: Chronotype was assessed twice with the Munich Chronotype Questionnaire 7 years apart in the Netherlands Study of Depression and Anxiety (T1: N = 1842, mean age (SD): 42.63 years (12.66)) and T2: N = 1829, mean age (SD) 50.67 (13.11)). The longitudinal association between change in age and change in chronotype was tested using a generalized estimated equation analysis adjusted for covariates (including level of depressive symptoms). Using age-bins of 5 years (age at T2), change in chronotype between T1 and T2 was analyzed with Linear Mixed Models. Results: We found a change towards an earlier chronotype with higher age (B (95% CI): -0.011 (-0.014-0.008), p < 0.001). For the age-bins, the difference in chronotype was significant for the 25-29 years age-bin. Limitations: The sample did not include individuals younger than 19 years or older than 68 years. Conclusions: In the whole sample chronotype changed towards becoming more morning-type over a period of 7 years, but this change was only significant for those aged 25-29 years. The study was performed in a large naturalistic cohort study with a wide age-range, including patients with a diagnosis of depressive and anxiety disorder and healthy controls. Show less
Background Chronotype is an individual's preferred timing of sleep and activity, and is often referred to as a later chronotype (or evening-type) or an earlier chronotype (or morning-type). Having... Show moreBackground Chronotype is an individual's preferred timing of sleep and activity, and is often referred to as a later chronotype (or evening-type) or an earlier chronotype (or morning-type). Having an evening chronotype is associated with more severe depressive and anxiety symptoms. Based on these findings it is has been suggested that chronotype is a stable construct associated with vulnerability to develop depressive or anxiety disorders. To examine this, we test the stability of chronotype over 7 years, and its longitudinal association with the change in severity of depressive and anxiety symptoms.Methods Data of 1,417 participants with a depressive and/or anxiety disorder diagnosis and healthy controls assessed at the 2 and 9-year follow-up waves of the Netherlands Study of depression and anxiety were used. Chronotype was assessed with the Munich chronotype questionnaire. Severity of depressive and anxiety symptoms were assessed with the inventory of depressive symptomatology and Beck anxiety inventory.Results Chronotype was found to be moderately stable (r = 0.53) and on average advanced (i.e., became earlier) with 10.8 min over 7 years (p < .001). Controlling for possible confounders, a decrease in severity of depressive symptoms was associated with an advance in chronotype (B = 0.008, p = .003). A change in severity of anxiety symptoms was not associated with a change in chronotype.Conclusion Chronotype was found to be a stable, trait-like construct with only a minor level advance over a period of 7 years. The change in chronotype was associated with a change in severity of depressive, but not anxiety, symptoms. Show less
Background: The role of chronotype, the individual timing of sleep/activity, has been studied in relation todepressive and anxiety disorders. A cross-sectional association between a depressive... Show moreBackground: The role of chronotype, the individual timing of sleep/activity, has been studied in relation todepressive and anxiety disorders. A cross-sectional association between a depressive episode and evening-typehas been identified. However, until now the predicting capacity of chronotype concerning persistence of psy-chiatric disorders remains unclear. Our aim is to examine whether a later chronotype in patients with a de-pressive and/or anxiety disorder can serve as a predictor of a persistent course.Methods: A subsample of patients with a depressive and/or anxiety disorder diagnosis and chronotype data ofthe longitudinal Netherlands Study of Depression and Anxiety (NESDA) was used. Diagnosis of depressive andanxiety disorders (1-month DSM-IV based diagnosis) were determined at baseline (n = 505). From this grouppersistence was determined at 2-year (FU2) (persistent course: n = 248, non-persistent course: n = 208) and 4-year follow-up (FU4) (persistent course: n = 151, non-persistent course: n = 264). Chronotype was assessed atbaseline with the Munich Chronotype Questionnaire.Results: A later chronotype did not predict a persistent course of depressive and/or anxiety disorder at FU2 (OR(95% CI) = 0.99 (0.83–1.19), P = 0.92) or at FU4 (OR (95% CI) = 0.94 (0.77–1.15), P = 0.57).Limitations: Persistence was defined as having a diagnosis of depressive and/or anxiety disorder at the two-yearand four-year follow-up, patients may have remitted and relapsed between assessments.Conclusion: Chronotype, measured as actual sleep timing, of patients with a depressive or anxiety disorder didnot predict a persistent course which suggests it might be unsuitable as predictive tool in clinical settings. Show less
