American psychologists from Stanford University in California have identified a cognitive biotype (a group with common characteristics) of people susceptible to major depressive disorder (MDD). They concluded that severe depression is associated with certain features in the functioning of the brain. The study was published in the scientific journal magazine JAMA Network Open.
MDD is a debilitating disease that affects millions of people worldwide. It is characterized by persistent sadness, feelings of hopelessness, and loss of interest or pleasure in most activities. Although depression is typically associated with emotional symptoms, cognitive impairment is increasingly recognized as an important part of this disorder. These cognitive deficits may include difficulties with memory, attention, decision-making, and executive function, which includes the ability to plan, organize, and manage tasks.
Using machine learning and cluster analysis, researchers identified a subgroup of MDD patients characterized by significant cognitive impairment. This cognitive biotype was associated with greater core symptoms (e.g., insomnia, slow processing) and functional impairment compared to other MDD patients.
Moreover, this biotype showed decreased neural activation in key brain regions, particularly the right dorsolateral prefrontal cortex (dLPFC) and dorsal anterior cingulate cortex (dACC), which are critical for cognitive control. Additionally, response and recovery rates were lower when treated with antidepressants in the cognitively impaired group.
The findings highlight the need to develop treatments that target specific cognitive impairments and their underlying mechanisms, the researchers said.
Previous scientists discovered The relationship between mental disorders and physical diseases.