Large Brain Network Linked To Attention Found In People With Depression

A research study revealed that a large brain network that is related to attention is found in people having depression. It is even present when the symptoms of depression are less intense.

The research disclosed that the symptoms of depression keep changing over time but with the imaging of brain activities, it is noted that the network of the brain fluctuates with variations in mood changes and feelings.

The study used long-term brain imaging data that a large brain was constantly utilizing the small details responsible for guiding attention. It is nearly two times larger in people troubled with depression as compared to those who are experiencing symptoms of depression.

This part of the brain network does change. It stays large throughout the phases of depression, even when the intensity of depression is low or high. The results of the study that were published on September 4 in Nature would help in devising brain stimulation therapies for patients of depression.

Charles Lynch’s team worked on large brain network project

Charles Lynch, a neuroscientist at Weill Cornell Medical College said, “Honestly, when we started this project, we weren’t expecting necessarily to find stable, trait-like differences in brain [activity patterns] in people with depression. We were more interested in looking for things that would change over time as their symptoms fluctuate”.

Lynch explained that they started off the project with the aim in mind to look for reasons for mood changes and what drives the large brain nexus to get affected by them. The mapping of the brain network was to be recorded over time and fluctuations were expected.

People with and without depression were included

However, this did not happen. The existing MRI datasets allowed Lynch’s team to have a closer look at the activity. More than a hundred people’s brains were examined, both including with and without depression.

The own ratings of patients for their depression were also taken into account each time the scan was made. The results showed that the networks of brain areas that were most coordinated were found with a salience network.

What is a salience network and how does it fit in?

A salience network is known for determining relevant stimuli and guiding attention. It was approximately two times larger in people with depression. The same network directs the activity of the other two networks:

• One that controls self-focused thinking
• Other that facilitates memory during goal-directed tasks

The salience network is also meant to record the reward processing and identify the stimuli that should be paid more attention to. With an enlarged salience network, the size of the neighboring networks becomes small.

Checking the results in children

To further strengthen the results of the study, the team tried to find the depression patterns and salience network mechanisms in adolescents who are usually at risk of developing depression. Fifty-seven children aged 13 to 14 years didn’t have depression in the beginning. Those children later developed depression and showed the same enlarged salience network as compared to those who were not depressed.

The findings of several previous studies were unclear where they said salience networks might be linked to depression. The current study showed a clear mapping of this network with the large brain web activity, extended high for depression patients.

Two patients with bipolar disorder II disorder showed a massive increment in their salience networks while those suffering from autism or obsessive-compulsive disorder did not. A neuroscientist at UCLA, Lucina Uddin, who was not part of this study, remarked later that these findings would be helpful in the future to shape the therapies for depression patients and follow-up with their results whether their salience network was reduced later or not.

Future direction

Lynch also seemed positive with the results and elucidated that there is an opportunity to incorporate this information to instigate functional brain networks in an organized manner. It would assist in administrating depression therapies, for both adults and children.