Do self-criticism and somatic symptoms play a key role in chronic depression? Exploring the factor structure of Beck depression inventory-II in a sample of chronically depressed inpatients.

•Beck Depression Inventory-II is among the most widely used screening tools for depression, but the factor structure varies in different sub-samples.•Exploratory structural equation modeling indicates the factor structure of BDI-II for chronically depressed inpatients is best explained by a bifactor model with one general factor and two sub-factors defined by self-criticism and somatic symptoms•Invariance tests indicate stability of the model across primary diagnoses and presence of comorbidity.•Clinicians could benefit from paying special attention to the subfactors identified, as the findings may have implications for the treatment choice for patients with chronic depression.