How daily rhythm preferences relate to insomnia and depression through sleep habits in older adults with and without depression

A significant mediation effect was observed where chronotype influenced depressive symptoms through insomnia severity in older adults with depression.

• Chronotype, as measured by the Morningness-Eveningness Questionnaire, is linked to depression severity in older adults.
• Insomnia severity, assessed with the Insomnia Severity Index, fully mediates the relationship between chronotype and depressive symptoms.
• Sleep hygiene practices are associated with the interplay between chronotype and insomnia severity.
• Both depressive symptoms and sleep hygiene act as partial mediators in the relationship between chronotype and insomnia severity.

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