Disrupted Brain Activation and Deactivation Pattern during Semantic Verbal Fluency Task in Patients with Major...

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Science

Background:

• Major depressive disorder (MDD) is associated with cognitive impairment.
• The semantic verbal fluency task is a sensitive cognitive marker for MDD.
• Neural processing dysfunctions in acute depression require investigation.

Purpose of the Study:

• To investigate neural processing dysfunction in acute MDD using fMRI.
• To examine the effects of a 6-week pharmacological intervention on brain activity in MDD patients.
• To identify specific brain regions and networks affected in MDD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used.
• Sixteen MDD patients and 16 healthy controls (HC) participated.
• Participants completed a semantic verbal fluency task.

Main Results:

• MDD patients showed hypoactivation in prefrontal, parietal, and limbic regions compared to HC.
• MDD patients exhibited hyperactivation in the left precuneus compared to HC.
• Treatment normalized hypoactivity in the left dorsolateral prefrontal cortex (DLPFC) and hyperactivity in the precuneus.

Conclusions:

• Left DLPFC hypoactivity and precuneus hyperactivity in MDD may reflect dysregulation of anticorrelated brain networks.
• This network dysregulation during cognitive tasks could be crucial in MDD pathophysiology.
• Anticorrelated brain network function in MDD warrants further investigation.