Frontostriatal salience network expansion in individuals in depression.

Area of Science:

• Neuroscience
• Psychiatry
• Brain Imaging

Background:

• Previous neuroimaging studies reveal subtle brain differences in depression, limiting mechanistic understanding and risk factor identification.
• Depression is episodic, yet few longitudinal neuroimaging studies exist to explain mood state transitions.
• Precision functional mapping in healthy individuals shows behaviorally meaningful brain network differences, but this approach was unexplored in depression.

Purpose of the Study:

• To investigate brain network topography in depression using precision functional mapping.
• To identify trait-like brain alterations associated with depression risk.
• To understand dynamic connectivity changes related to mood states and symptom fluctuations.

Main Methods:

• Utilized precision functional mapping with deeply sampled individuals across multiple cohorts.
• Analyzed longitudinal neuroimaging data, including up to 62 scans over 1.5 years for some participants.
• Examined network border shifts and frontostriatal circuit connectivity.

Main Results:

• The frontostriatal salience network was found to be nearly twofold expanded in the cortex of most individuals with depression.
• This expansion was stable over time, unaffected by mood state, and present in children before depression onset.
• Longitudinal analyses revealed frontostriatal connectivity changes that tracked specific symptoms and predicted future anhedonia.

Conclusions:

• A trait-like brain network topology, specifically salience network expansion, may confer risk for depression.
• Mood-state-dependent connectivity changes in frontostriatal circuits predict the emergence and remission of depressive symptoms.
• Precision functional mapping offers new insights into the neural mechanisms underlying depression and its temporal dynamics.