A NEW study from Weill Cornell Medicine, New York, USA has revealed a unique pattern of brain activity that may predispose certain individuals to depression. Scans taken over 18 months showed that individuals with depression exhibit a nearly twofold expansion in the frontostriatal salience network, a brain region involved in processing rewards and integrating feedback with goals.
The study, involving both children and adults, utilised precision functional mapping to analyse individual brain network topography and connectivity, on deeply sampled neuroimaging data and found that the salience network expansion was detectable in individuals before the onset of depression. Longitudinal analysis tracked individuals over 1.5 years, linking changes in frontostriatal connectivity to specific depressive symptoms like anhedonia and anxiety. These changes were predictive of future symptoms, highlighting the salience network’s role in driving mood-state transitions in depression.
This research addresses the challenge of understanding depression’s episodic nature and mood-state fluctuations, a limitation in prior studies that relied on cross-sectional data. By following individuals across multiple scans, the study provides a clearer picture of how depressive symptoms evolve. In contrast to earlier research that used group-average approaches, precision functional mapping revealed personalised differences in brain network topology, offering deeper insights into the mechanisms of depression.
Further analysis of additional brain scan data suggested that a larger salience network in childhood might increase the likelihood of developing depression later in life. While the findings need further validation, the researchers hope this approach could eventually help predict depression risk and inform treatments for other neuropsychiatric conditions. The findings suggest that network expansion in depression may be a trait-like feature, potentially serving as a risk marker. This new approach could inform future therapeutic interventions, including brain stimulation techniques, targeting specific brain networks to treat depression.
The study marks a significant advancement in understanding the neurobiological underpinnings of depression and the identification of stable, mood-independent changes in the salience network opens new avenues for research into how brain network connectivity contributes to depression. The results could inform future research, potentially helping to refine treatment approaches and predict symptom progression.
Katie Wright, EMJ
Reference
Lynch CJ et al. Frontostriatal salience network expansion in individuals in depression. Nature. 2024;DOI:10.1038/s41586-024-07805-2.
