New study published in Nature on September 4, 2024 provides insight into how depression can change the size of our brain, as a specific brain network (the Frontostriatal salience network) nearly doubles in size if you have depression. The findings could have major implications in the treatment of the condition going forward.
The Frontostriatal Salience Network: What Is It?
The Frontostriatal salience network receives reward and filters external stimuli, a function necessary for mood. In depressed subjects, This network expands significantly — which could explain why the brains of such individuals have trouble processing rewards or controlling emotional response, according to new research led by a team at Weill Cornell Medicine in New York.
In people with depression, the network enlarged by about 73% when compared with healthy controls. This causes it to take more space in the brain leading other networks around to shrink. This discovery was consistent across multiple studies and patient groups, using advanced brain imaging techniques such as precision functional mapping.
How the Research Was Conducted
The research began by analyzing the brain scans of 57 individuals with depression, aged 41 on average, and compared them with the brains of 37 healthy participants. The conclusion was clear: the depressed group had a significantly larger frontostriatal salience network. Additionally, when the researchers repeated their study with much larger databases that included 932 healthy subjects and an additional 299 individuals with depression, the findings were confirmed.
They also examined brain images from children and discovered that those who later developed depression in their teens already had an enlarged frontostriatal salience network. This aligns with the notion that the network’s expansion may be part of a more generalized predisposition to developing depression, rather than being directly caused by or resulting from it.
Stable Expansion Over Time
The volume of the Frontostriatal salience network remained unchanged across mood states or after treatment with transcranial magnetic stimulation. However, synchrony in the brain signals within the network weakened when patients exhibited depressive symptoms, suggesting these changes were tied to depression severity.
The fact that the size of this network remains stable over time suggests it could serve as a trait marker for depression, potentially enabling the identification of the condition in its early stages before symptoms manifest.
Future Implications for Depression Treatment
The study results offer fresh understanding of the biological basis for depression. Dr. Charles Lynch, a co-author of the study, said learning how that network grows could lead to new approaches for preventive treatment. According to the researchers, this finding could lead to individualized interventions based on brain topologies for treated patients.
While much remains to be explored, this research represents a significant step in understanding how depression alters the brain and highlights the potential for new therapeutic approaches targeting the Frontostriatal salience network.
Published original study available here: Nature.com – Frontostriatal salience network expansion in individuals in depression