Researchers have gained new insights into how and why some people suffer from depression after discovering that a certain brain network is much larger in people diagnosed with the condition.
The surface of the brain is a communication junction box where different areas communicate with each other to carry out certain processes. But there’s a limited amount of space these networks can share, according to .
Now researchers say that in people with depression, a larger part of the brain is involved in the network that controls attention to rewards and threats.
“(Network, no) It takes up more space on the surface of the brain than we see as typical in healthy people,” said study co-author Dr. Charles Lynch of Weill Cornell Medicine in New York.
The portion due, 73% higher in patients with depression
He added that the expansion meant that the size of other – often neighboring – brain networks was smaller. Lynch and colleagues report how they used precision functional mapping, a new approach to brain imaging that analyzes a series of fMRI (functional MRI) scans of each individual.
The team applied this method to 141 people with depression and 37 people without depression, which allowed them to accurately measure the size of each participant’s brain networks. Then they took the average size for each group.
They found that the so-called frontostriatal network was expanded by 73% on average in participants with depression compared to healthy people.
These data were supported by an analysis of individual brain scans previously collected from 932 healthy individuals and 299 with depression.
The team stated that the size of this brain network in people with depression did not change as a function of time, mood or transcranial magnetic stimulation treatment.
A risk factor for developing depression
However, brain signals between different parts of the network became less synchronized when participants were experiencing certain symptoms of depression, and these changes were also associated with the severity of future symptoms.
The team added that an analysis of brain scans from 57 children who went on to develop depression in adolescence showed that this brain network was expanded years before their symptoms appeared, while it was also expanded in adults with depression with late onset.
The researchers said this suggests that an enlarged brain network could be for the development of depression, rather than a consequence of the condition.
The team added that their results could provide a way to explore whether certain people may be at increased risk of developing depression and could help develop personalized treatments.
