Emotion processing and regulation in bipolar disorder: a review

Area of Science:

• Neuroscience
• Psychiatry
• Neuroimaging

Background:

• Bipolar disorder (BP) involves mood dysregulation, alternating between mania/hypomania and depression.
• Emotional extremes in BP suggest a core inability to regulate emotions.
• Functional neuroimaging, particularly fMRI, is crucial for understanding the neural underpinnings of BP.

Purpose of the Study:

• To review the current functional magnetic resonance imaging (fMRI) literature on adult patients with bipolar disorder.
• To examine fMRI studies utilizing emotion processing or regulation paradigms.
• To synthesize findings on neural abnormalities associated with mood states in BP.

Main Methods:

• Conducted a PubMed search using keywords: bipolar disorder, fMRI, mania, bipolar depression, bipolar euthymia, emotion, and amygdala.
• Included studies on adult patients using emotion activation tasks.
• Focused on fMRI research investigating emotion processing and regulation in BP.

Main Results:

• Multiple fMRI studies have investigated BP subjects during mania and euthymia, with fewer during depression.
• Abnormalities in frontal-limbic regions, specifically the amygdala and prefrontal cortex (PFC), have been demonstrated.
• The amygdala, critical for emotion, and the PFC, involved in regulation, were key areas of focus.

Conclusions:

• Amygdala activation in BP varies significantly with mood state.
• The prefrontal cortex (PFC) shows persistent hypoactivation across all mood states in BP.
• Disrupted frontal-limbic network function likely underlies emotional dysregulation and lability in bipolar disorder.