A network of interacting brain regions known as the default mode network was found to have stronger connections in adults and children with a high risk of depression compared to those with a low risk, according to scientists at Columbia University’s Mailman School of Public Health and New York State Psychiatric Institute. These findings suggest that increased default mode network (DMN) connectivity is a potential precursor, or biomarker, indicating a risk of developing major depressive disorder. The study was published online in Neuropsychopharmacology.
The researchers used magnetic resonance imaging to compare people at high risk for depression to those at low risk based on their family history of depression. This approach allowed researchers to look for differences in the brain that are not a consequence of the depression itself, since the disorder had not yet manifested in most of the individuals.
The interacting brain regions are more active when people are focused on internal thinking, such as ruminative thoughts. These increased connections previously seen in individuals with major depressive disorder may relate to ruminative symptoms, and typically normalize with antidepressant treatment. The study reveals that the process of these increasing connections may occur before the onset of depression.
“Our findings suggest that looking at activity in the DMN may offer an objective method of identifying people who are at risk of developing major depression,” said Mailman School lead author Myrna Weissman, PhD, the Diane Goldman Kemper Family Professor of Epidemiology and chief of the Division of Epidemiology at New York State Psychiatric Institute. “This may represent another way toward advancing prevention and early intervention for this major public health issue.”
According to the authors, if this insight proves correct, behavioral interventions that improve the functioning of the default mode network, such as meditation and mindfulness, could be used to address a brain-based problem (increased network connections), before it leads to a depressive illness.
The study, titled “Increased Default Mode Network Connectivity in Individuals at High Familial Risk for Depression,” was supported in part by NIMH grants R01-MH036197 and K23-MH091249 and the Sackler Institute for Psychobiology.