Those with a genetic predisposition to lower production rates of a certain chemical of the brain, one that denotes a regulation of appetite and stress, could be at a heightened risk of suffering from the severer forms of depression, new research has concluded.
It is believed that the findings will open the door for understanding just how depression can affect some people more than others, and may lead to a paving of the way for an individualised form of treatment.
New therapies may be created as a result, according to researchers at the University of Michigan. They have stated, “We’ve identified a biomarker, it is genetic variation, one that is linked with increased risk of major depression.” This was said by the senior author of the study Jon-Kar Zubieta, who is a professor of psychiatry and radiology.
Also stated was that, “This appears to be another mechanism, independent of previous targets in depression research, such as serotonin, dopamine and norepinephrine.”
Measurably stronger responses in the brain have been concluded to occur when there are negative inputs to those persons, this relates also to their psychological response to the domain of physical pain. This occurs in people who produce neuropeptid Y (NPY) a brain molecule to a lesser degree than is normal in the individual.
It has been determined also that a large proportion of these people are amongst the population who have been diagnosed with a mental disorder in particular a major depressive one.
The methods of the study were as follows:
First: The participants in the study were broken down into three different groupings. They were segregated based on the levels of this brain molecule they produce, low medium and high.
Second: Magnetic Resonance brain imagery was used to gain a view of the brain activity of these subjects. These images were taken as certain words were read by the subjects. The words were neutral, negative, and positive e.g. material, murderer, hopeful. The study reported that, “In response to negative words, subjects in the low NPY group showed strong activation in the prefrontal cortex, which is involved with processing emotion, while subjects with high NPY demonstrated a much smaller response.”
The second trial allowed a different means of assessment. The subjects were given a stress challenge, and asked to give a description of their mental state preceding, and in the wake of the challenge. The stress test involved a saline solution being injected into their jaw muscles, a precursor to the experience of short term pain.
It was found that those with the lower levels of the bran molecule experienced more negativity from the stress than those with normal levels. This was pre and post the stress test. The result showing that in them there was a heightening in not only the anticipation of the pain, but also upon receipt of the pain there was more negativity regarding the reflection upon the pain itself.
Finally: The people who had a major depressive disorder in the group were compared for NPY genotypes against a control group. It was found again that there is in fact an overrepresentation amongst those in the group with depression.
Another of the lead authors of the study Brian Mickey has stated that the same can be found in the measure of the genetic features of just about any person. It is hoped by this man that the finding of this result will guide a path for researchers to assessing an individual’s risk for the development of anxiety and depression.
“These are genetic features that can be measured in any person,” said lead author Brian Mickey, an assistant professor in the Department of Psychiatry at the University of Michigan Medical School. “We hope they can guide us toward assessing an individual’s risk for developing depression and anxiety.”