A team from Weill Cornell Medicine in New York City says it has found evidence of an oversized brain structure in patients experiencing depression. According to the researchers, this structure is about twice the size in depressed people as it is in patients with no depression.
The structure is called the frontostriatal salience network. What it does is not yet well understood, but prior research indicates that it is involved in how the brain processes stimuli and “rewards.”
The Weill Cornell team is hopeful that its discoveries may lead to better treatments for depression if they can figure out what the network structure is doing, and how to effectively target it. In their journal article describing the research, the team said the network structure is “expanded nearly twofold” in the cortex of people who are suffering from depression. They say they replicated their findings several times, and found at least three ways that the network structure encroaches on surrounding areas of the brain in depressed patients. It is not clear whether this phenomenon is a cause, or an effect, of depression.
An interesting aspect of the research is the use of precision functional mapping, a fairly new approach that allows investigators to get clearer and more detailed views of brains and the structure being studied. The team examined brain scans of 57 people (average age ws 41) and compared those to scans from a control group of 37 health people with no depression. They then compared their findings with other databases that had a larger number of patient participants.
To further test their data, the team replicated their work on a smaller sample of patients, and they also compared results from a study of 114 children who were scanned before and after they got a diagnosis of depression. The data from all studies lined up well.
The study on children may begin to answer the question of whether the expanded brain structure is a cause or an effect of depression. Researchers noted that the network was larger than normal in the children before they got a diagnosis, suggesting that it may be an inheritable risk factor.
