Left Ventrolateral Prefrontal Cortical Activity During Reward Expectancy and Mania Risk

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Mania/hypomania is the hallmark of bipolar disorder (BD).
• Misdiagnosis of BD as major depressive disorder (MDD) is common, necessitating reliable neural markers for early diagnosis.
• Identifying neural correlates of mania/hypomania risk is vital for developing targeted treatments.

Purpose of the Study:

• To replicate the association between left ventrolateral prefrontal cortex (vlPFC) activity during reward expectancy (RE) and mania/hypomania risk.
• To investigate the influence of a history of MDD on this association.
• To compare RE-related vlPFC activity in individuals with and at risk for BD.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to measure brain activity during an RE task.
• Participants included young adults (18-30 years) with varying psychopathology, including a new sample, two test samples, and individuals with euthymic BD.
• Activity in the left vlPFC during RE was analyzed in relation to mania/hypomania risk scores and MDD history.

Main Results:

• A positive association was found between left vlPFC activity during RE and mania/hypomania risk across samples.
• This association remained significant after excluding individuals with a history of MDD.
• Individuals at higher risk for mania/hypomania and those with euthymic BD exhibited greater RE-related left vlPFC activity compared to lower-risk groups.

Conclusions:

• Elevated left vlPFC activity during RE is a neural marker associated with mania/hypomania risk.
• A history of MDD may attenuate this neural association.
• These findings highlight the left vlPFC as a potential therapeutic target for interventions aimed at individuals with or at risk of mania/hypomania.