Stability of chronotype over a 7-year follow-up period and its association with severity of depressive and anxiety symptoms.

Stella J M Druiven,Harriëtte Riese,Stefan E Knapen,Benno C M Haarman,Johanna H M Hovenkamp‐Hermelink,Ybe Meesters,Brenda W J H Penninx,Niki Antypa,Robert A Schoevers,Jeanine Kamphuis

doi:10.1002/da.22995

Abstract

BackgroundChronotype 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.MethodsData 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.ResultsChronotype 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.ConclusionChronotype 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.

Highlights

Chronotype is an individuals preferred timing of sleep and activity, and is often referred to as a later chronotype or an earlier chronotype
For the generalized estimating equation (GEE), sex was treated as time‐ independent variable, whereas severity of depressive and anxiety symptoms, severity of insomnia, age, children in the household and employment status were treated as time‐dependent variables
In line with the findings of the main GEE analyses, the advanced chronotype group showed an association between a decrease in severity of depressive symptoms and a decrease in MSFsc in Model 1, where a decrease of 1 unit of depressive symptoms was associated with a decrease of 0.009 MSFsc

Summary

| INTRODUCTION

Chronotype is an individuals 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). To the best of our knowledge, only one study addressed this question (Müller et al, 2015) They found that the preference for sleep timing in depressive patients, as assessed with the MEQ, was highly correlated (r = 0.82, p < .001) over the course of a hospitalization period (mean stay: 48.6 days), despite a significant improvement in patients depressive symptoms. Another study showed that evening‐type was predictive of an increase of depressive symptoms and a depressive diagnosis 1 year later in a group of adolescents (Haraden, Mullin, & Hankin, 2017) These conflicting results illustrate the need for more longitudinal studies on the associated changes in severity of depressive and anxiety symptoms and chronotype. In the current study we aim to: (a) Test the 7‐year stability of chronotype, and (b) analyze whether a longitudinal association exists between a change in severity of depression and anxiety symptoms and change in chronotype

| METHODS

| RESULTS

| DISCUSSION

DATA AVAILABILITY STATEMENT