Night Owls and Lone Wolves

Abstract

Diurnal preference for evening time has been associated with poorer physical and mental health outcomes. In the current report, perceived loneliness and brain structure (hippocampal and amygdala volumes) were compared in a large (N = 4684) sample of morning- and evening-type individuals. Definite eveningness was associated with increased odds for reporting self-perceived loneliness and lonely evening-types had significantly smaller right hippocampal volume as compared to morning and more socially connected evening types. These data add to the mounting body of evidence linking an evening profile with increased risk for psychiatric disorder.