Associations between morningness/eveningness and psychopathology: an epidemiological survey in three in-patient psychiatric clinics.

Objective: This study aims to examine the association between the chronotype (morningness/eveningness) and specific mental disorders.

Methods: Cross-sectional epidemiological study conducted in three in-patient clinical settings. A total of 1468 consecutive in-patients who gave their written consent were enrolled. On the admission day, patients filled sleep questionnaires and a nurse filled a Clinical Global Impressions scale. Hospitalization reports and ICD-10 diagnoses were collected.

Results: Sleep/wake schedule was similar between the psychiatric diagnoses. On the other hand, morning type patients had an earlier bedtime, earlier wakeup time and shorter sleep duration than the other chronotype regardless of the diagnosis. In multivariate models, patients with a depressive disorder or a psychosis were more likely to be morning type. Patients with an anxiety disorder, addiction disorder or personality disorder were more likely to be evening type.

Conclusions: Age and sleep/wake schedule are contributing factors for the chronotype but mental disorders too appeared to modulate chronotype preferences.