Cognition-Related Brain Networks Underpin Cognitive, Emotional, and Somatic Symptom Dimensions of Depression

Abstract

The latest functional neuroimaging evidence suggests that the abnormal activation and connectivity of cognition-related brain networks may account for different symptom dimensions of unipolar depression. In particular, abnormal functioning of the autobiographic memory network (AMN) and cognitive control network (CCN) is central to the emotional, somatic, and cognitive symptomatology of depression. Chronic hyperactivity of the self-focused AMN is linked to pathological introspection; namely, brooding, self-blame, and rumination. In parallel, underengagement of the CCN is associated with indecisiveness, negative thoughts, poor concentration, and distorted cognitive processing. Downstream effects include dysregulation of networks linked to the somatic and emotional symptoms of depression, namely the cortico–subcortical affective network and salience network. AMN–CCN dynamics can change between individuals and over time, plausibly accounting for both the pleomorphic presentation of depression and its fluctuating course. Framing depression as a disorder of neurocognitive networks directly links clinical features to neurobiology, in line with gold standard psychiatric research guidelines.