Role of chronotype in depression

Table 2 Summary of key studies: Association between chronotype and depression

Population	Study design	Key findings	Ref.
Children and adolescents	Longitudinal study	Evening chronotype was associated with earlier depressive symptoms and history of depression diagnosis	Koo et al[23]
Korean high school students	Cross-sectional study	Evening chronotype was significantly associated with increased depression risk	Koo et al[23]
Chinese college students during COVID-19 pandemic	Cross-sectional study	Evening chronotype was more prevalent among students with depressive symptoms, with sleep quality mediating this association	Zhang et al[24]
Young male military recruits	Cross-sectional study	Evening chronotype was associated with depressive symptoms and higher symptom severity	Tonon et al[25]
Perinatal women	Cohort study	Perinatal women with evening chronotype showed a higher risk of developing depressive symptoms	Garbazza et al[26]
General adults	Cross-sectional study	Evening chronotype was linked to increased depression risk, while morning chronotype showed a protective effect	Mao et al[27]
Rural population	Cross-sectional study	Social jetlag correlated with chronotype and served as a risk factor for depression; evening chronotypes had more severe depression	Levandovski et al[28]
Finnish Hospital personnel	17-year cohort study	Evening chronotypes were more vulnerable to self-reported mood disorders than morning chronotypes	Cheng et al[29]
Large Dutch cohort	Cohort study	A significant association was found between evening chronotype and depression	Antypa et al[30]
United Kingdom biobank and older Finnish twin cohort	Genome-wide association + cohort study	Evening chronotype predicted increased incidence of psychiatric disorders, including MDD; evening chronotypes without sleep inertia had no higher risk than morning chronotypes	Burns et al[31]
General adults (genetically predicted)	Mendelian randomization study	Genetically predicted morning chronotype was associated with a 23% lower risk of depression	Daghlas et al[33]
Korean adults	Cross-sectional study	Evening chronotype was associated with increased depression risk in women but not men; women with evening chronotype had 1.5-fold higher depression risk than men	Kim et al[35]
Adults from NHANES 2017-2020	Cross-sectional study	Evening chronotype was associated with higher levels of depressive symptoms	Seizer et al[41]
Patients with depression	Cross-sectional study	Evening chronotype was linked to higher suicidality, more severe symptoms, lower remission rates, and poorer response to antidepressants in depression patients	Mokros et al[44]; Rasmussen et al[45]; Chan et al[46]

COVID-19: Corona virus disease 2019; MDD: Major depressive disorder; NHANES: The National Health and Nutrition Examination Survey of the United States.