Media release

From: Springer Nature

2.  Neuroscience: Depression may be associated with an expanded brain network

A brain network observed to be nearly two times larger in most sampled individuals with depression than in healthy counterparts is identified in a study published in Nature. The findings highlight new potential targets for future therapeutic interventions.

Despite decades of neuroimaging studies, only modest differences in brain structure and connectivity have been identified in people with depression, thereby limiting current understanding of the mechanisms or risk factors for the onset of the illness. In addition, a lack of long-term studies, accounting for the episodic nature of depression, have limited the investigation of the mechanisms underlying mood state transitions in depression.

To investigate the neurobiological underpinnings of depression, Charles Lynch, Conor Liston and colleagues used a technique called precision functional mapping in a primary analysis of 141 individuals (average age 41 years) with a diagnosis of major depression and 37 healthy controls. Analyses were replicated in multiple existing large datasets. The authors found that a group of brain regions, collectively known as the frontostriatal salience network, had expanded nearly two-fold in the brains of most individuals studied with depression, compared to controls. This expansion was found to be stable over time, unaffected by changes in mood state, and could be detected in children before the onset of depressive symptoms in adolescence. The latter suggests that expansion of the frontostriatal salience network may potentially serve as a biomarker for depression risk, although the authors note that further studies are needed to confirm this association. Longer-term analyses of individuals scanned up to 62 times over a period of 1.5 years identified connectivity changes associated with depression symptoms.

In summary, the findings reveal differences in network size, shape and spatial location that are associated with depression.