Characterising a stress-sensitive default mode network (DMN) deficit in major psychiatric disorders

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Childhood trauma (CT) is a significant risk factor for cognitive impairment.
• This impairment is observed across various psychiatric disorders, indicating a potential transdiagnostic mechanism.
• The default mode network (DMN) is implicated in cognitive functions and psychiatric conditions.

Purpose of the Study:

• To investigate whether atypical default mode network (DMN) connectivity mediates the relationship between childhood trauma (CT) and cognitive impairment.
• To examine this transdiagnostic hypothesis in a large sample of young adults with and without psychiatric disorders.

Main Methods:

• Utilized data from 1851 individuals (aged 18-25), including patients with depression, eating disorders, alcohol use disorder, psychosis, and ADHD.
• Assessed childhood trauma (CT) using the Childhood Trauma Questionnaire (CTQ).
• Measured cognitive function via the CANTAB spatial working memory task and DMN connectivity using fMRI (medial PFC, lateral parietal, PCC).

Main Results:

• Patients exhibited significantly reduced DMN connectivity between key nodes (PFC, LP, PCC) and the rest of the brain.
• Reduced DMN connectivity was found to mediate the association between higher CT scores and poorer cognitive performance.
• Findings demonstrated a transdiagnostic effect, with some regional variations observed in depression.

Conclusions:

• Atypical DMN connectivity serves as a transdiagnostic mechanism linking childhood trauma (CT) to cognitive impairment.
• These findings highlight a specific neural pathway through which early life adversity impacts cognitive function across psychiatric disorders.
• Interventions targeting DMN function may be beneficial for individuals with a history of CT and cognitive deficits.