Associations between depression, lifestyle and brain structure: A longitudinal MRI study

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Depression is linked to reduced grey matter volume.
• Lifestyle factors in depression and their impact on brain structure are understudied.
• The longitudinal relationship between depression, lifestyle, and brain structure is largely unknown.

Purpose of the Study:

• To investigate the cross-sectional and longitudinal associations between depression, lifestyle factors, and brain structure.
• To explore how depression and lifestyle influence brain regions such as the medial orbitofrontal cortex (mOFC), rostral anterior cingulate cortex (rACC), and hippocampus.
• To examine changes in brain structure over periods of up to 9 years in relation to depression and lifestyle.

Main Methods:

• Utilized longitudinal structural MRI data from 347 participants (609 observations).
• Derived cortical thickness of mOFC and rACC, and hippocampal volume using FreeSurfer.
• Employed Generalized Estimating Equations to analyze associations between depression, lifestyle (BMI, smoking, alcohol, physical activity, sleep), and brain structure.

Main Results:

• Depression status and severity were negatively associated with rACC thickness.
• Body Mass Index (BMI) was negatively associated with mOFC thickness.
• Moderate alcohol consumption was positively associated with mOFC thickness.

Conclusions:

• Depressive symptoms and diagnosis are independently linked to reduced rACC thickness.
• BMI is associated with thinner mOFC, while moderate alcohol consumption is linked to thicker mOFC.
• No longitudinal associations were found, suggesting brain alterations may be long-term consequences or vulnerability indicators, not dynamic changes related to depression's course.