New research shows that the salience network in the brains of people with depression is larger

As of September 8, 2024, a new study led by researchers from Weill Cornell Medicine in the United States shows that the "salience network" in the brains of people with depression is much larger than that of healthy people, and even if emotional symptoms are relieved or disappear, this area will not shrink. The relevant paper was published in the British journal Nature.

The brain can be divided into different sub-networks. The "salience network" is composed of multiple regions related to cognition and emotion and is responsible for monitoring the external world and determining the response of other brain networks to new information and stimuli. Researchers conducted functional magnetic resonance imaging on the brains of 135 patients with major depression and found that their "salience network" is larger than that of healthy people, and the proportion is at most about twice that of healthy people.

To determine whether the "salience network" expands when depressive symptoms occur, the researchers observed several patients over a long period of time. For up to 18 months, imaging was performed weekly and patients were asked to state their symptoms. The results show that the size of this network remains unchanged when symptoms change in severity, but the activity status is related to symptoms and can be used to predict whether there will be symptoms in the next week.

The research team also ***yzed the data of a study on brain development in children. Among 12,000 survey subjects, 57 children with depression during adolescence had a larger "salience network" in the brain at the age of 9 than healthy children of the same age. The researchers speculate that a larger "salience network" may be related to genetics. Under a depressive state, continuously paying attention to negative stimuli may lead to overuse of this area and further expansion.

People with depression lose interest in normal activities and are accompanied by symptoms such as negative emotions and difficulty in thinking and making decisions. It was previously known that there is a decrease in neural synapses in specific brain regions of patients, but the understanding of the neurobiology of this disease is still not in-depth. It is mainly diagnosed by questionnaires and conversations, and there is a lack of diagnostic biomarkers.