Individual differences in depression are associated with abnormal function of the limbic system in multiple sclerosis...

Area of Science:

• Neuroscience
• Psychiatry
• Neurology

Background:

• Depression is a frequent comorbidity in multiple sclerosis (MS).
• The underlying brain mechanisms of depression in MS are not well understood.
• The role of limbic circuit activity and functional connectivity in MS-related depression requires investigation.

Purpose of the Study:

• To investigate the relationship between depression severity and limbic system activity and functional connectivity in MS patients.
• To identify specific brain regions and circuits associated with depression in the context of MS.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used in 77 MS patients.
• The Beck Depression Inventory (BDI) assessed depression levels.
• Functional connectivity analyses focused on the amygdala and hippocampus as seed regions, using multiple regression models.

Main Results:

• Depression scores negatively correlated with activity in the subgenual cingulate cortex.
• Reduced functional connectivity was observed between the hippocampus and orbitofrontal cortex/dorsolateral prefrontal cortex.
• Altered functional connectivity was found between the amygdala and dorsolateral prefrontal cortex.

Conclusions:

• Individual differences in depression among MS patients are significantly associated with altered limbic system activity.
• Functional connectivity patterns within the limbic system are implicated in the pathophysiology of depression in MS.
• These findings provide insights into the neural basis of depression in MS.