Structural and functional brain alterations in subthreshold depression: A multimodal coordinate-based meta-analysis

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Subthreshold depression (StD) is characterized by depressive symptoms not meeting full diagnostic criteria.
• Previous neuroimaging studies report diverse structural and functional brain abnormalities in StD, lacking consensus.
• Understanding the neural underpinnings of StD is crucial for early intervention.

Purpose of the Study:

• To test the hypothesis of spatially convergent structural and functional brain abnormalities in StD compared to healthy controls.
• To identify consistent neuroimaging findings across multiple studies on StD.
• To provide insights for early screening and therapeutic targets for StD.

Main Methods:

• A multimodal meta-analytic approach using Activation Likelihood Estimation (ALE).
• Inclusion of 31 articles comprising 25 experiments with 1001 subjects diagnosed with StD.
• Analysis of various neuroimaging methods to identify convergent findings.

Main Results:

• Consistent differences between StD and healthy controls were found, primarily in the left insula.
• Exploratory analyses revealed structural atrophy and decreased functional activity in the right pallidum and thalamus in StD.
• Abnormal spontaneous activity in StD converged to the middle frontal gyrus, indicating spatially convergent impairments.

Conclusions:

• Coordinate-based meta-analysis confirms spatially convergent structural and functional impairments in subthreshold depression.
• Findings offer novel insights into the neural basis of StD.
• Identified brain regions may serve as potential targets for early screening and therapeutic interventions for StD.