Accelerated brain aging as a biomarker for staging in bipolar disorder: an exploratory study

Area of Science:

• Neuroscience
• Psychiatry
• Biomarker Research

Background:

• Bipolar disorder (BD) progression is typically staged by episode recurrence or inter-episodic functioning.
• Neurobiological underpinnings and biomarkers for BD staging remain largely unexplored.
• This study investigates brain structure and brain-predicted age difference (brain-PAD) as potential indicators of BD progression.

Purpose of the Study:

• To determine if global and (sub)cortical brain structures, and brain-PAD reflect illness progression in BD.
• To explore brain-PAD as a potential biomarker for staging bipolar disorder.

Main Methods:

• Analysis of 199 individuals with bipolar I disorder and 226 controls from the Dutch Bipolar Cohort.
• Utilized high-quality T1-weighted MRI scans to estimate global and (sub)cortical brain measures and brain-PAD.
• Examined associations between brain measures, brain-PAD, and established BD staging models.

Main Results:

• A higher brain-PAD correlated with advanced stages in the inter-episodic functioning model, but not the episode recurrence model.
• This association lost statistical significance after accounting for lithium use and comorbid anxiety.
• No significant associations were found between global or (sub)cortical brain measures and BD stages.

Conclusions:

• Brain-PAD shows a potential association with BD progression, specifically concerning inter-episodic functioning.
• The significance of brain-PAD as a BD progression biomarker is influenced by lithium use and anxiety comorbidity.
• Further investigation is crucial to clarify the complex interplay between brain-PAD, BD illness stages, and confounding factors like medication and comorbidities.