Frontopolar cortical inefficiency may underpin reward and working memory dysfunction in bipolar disorder

Area of Science:

• Neuroscience
• Psychiatry
• Cognitive Psychology

Background:

• Emotional dysregulation in bipolar disorder is linked to prefrontal cortex dysfunction and altered emotional processing.
• Understanding these neural underpinnings is crucial for developing targeted treatments.

Purpose of the Study:

• To investigate functional brain abnormalities in bipolar disorder during reward and working memory tasks.
• To identify common and distinct patterns of brain activation in patients compared to healthy controls.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used.
• 36 euthymic bipolar disorder patients and 37 healthy controls participated.
• Tasks included the Iowa Gambling Task (reward) and the n-back task (working memory).

Main Results:

• Bipolar disorder patients exhibited inefficient ventral frontopolar prefrontal cortex engagement during both tasks.
• Distinct medial-lateral segregation of this region was observed for reward and working memory.
• Increased activation was noted in the anterior cingulate cortex (reward) and insula (working memory) in patients.

Conclusions:

• Ventral frontopolar cortex dysfunction is implicated as a core abnormality in bipolar disorder.
• Aberrant activation in emotional processing regions occurs even in non-emotional tasks.
• These findings enhance understanding of the neural basis of bipolar disorder.