Chronotype, depression and hippocampal volume: cross-sectional associations from the UK Biobank

ABSTRACT

Diurnal preference for evening time has been associated with increased odds for current depression and a number of indices of the disorder. In the current study, the association between chronotype and depression was explored in a population-based sample of 5360 adults aged between 40 and 70 years. Previous work has also suggested that larger hippocampal volume may be protective against depression. In an additional, exploratory analysis, hippocampal volume was compared in never-depressed early and late chronotypes (N= 3004). Definite eveningness was significantly associated with increased odds for probable lifetime depression after controlling for a number of confounding factors including neuroticism. Hippocampal volume did not differ between never-depressed early and late chronotypes. The current results extend previous work and add further weight to the argument that late chronotype represents a risk factor for depression.

KEYWORDS:

• Chronotype
• depression
• biobank
• hippocampus

Acknowledgments

The author is grateful to all the participants who contributed to this research and to the Medical Research Council UK Biobank for generating such a valuable resource.

Conflict of interest

There author reports no conflicts of interest.

Supplementary Material

Supplemental data for this article can be accessed here.

Additional information

Funding

This research was supported by a small research grant from the University of Roehampton.