New approach in studying of neural connections can help to fight with depression

Scientists from Immanuel Kant Baltic Federal University have presented a new method of analysis of neural connections on the base of data of functional MRT, in frame of which authors reconstructed functional nets of brain of healthy people and patients with depression, and after that compared evaluable characteristics. Such method got the name “consensus approach” and enabled to find out significant differences between healthy people and people with major depressive disorder. Thus, it can make the diagnostics of disease easier. Results of the research supported by the grant of Russian Scientific Fund (RSF) are published in magazine Chaos: An Interdisciplinary Journal of Nonlinear Science.

Major depressive disorder (MDD) – is a mental illness that influences life quality of people greatly. The disease negatively affects working ability of a man, his activity, appetite, concentration, sleeping and even self-evaluation. According to WHO’s statistics nowadays 3.8 % of world’s population struggle with depression. There is a threat that by 2030 major depressive disorder will become a disease causing the biggest material and nonmaterial losses, that are measured by financial expenses, mortality, morbidity and other figures.

Complexity of diagnosing of MDD lies in the fact that there are no analyses that prove existence of the disease. The diagnosis is made by a psychiatrist on the base of the examination, interview and medical history. By this it is well-known that during MDD you observe a failure of production of molecules that participate in exchanging information between brain cells. That is why for diagnosing major depressive disorder you can use functional magnetic resonance tomography (fMRT). It enables to analyze functional neural connections and watch activity of all brain structures. With a help of such approach, it is possible to compare how different brain regions, situated far from each other, react on extrinsic stimuli and how brain structures interact with each other.

Scientists from Immanuel Kant Baltic Federal University (Kalinngrad), Madrid Polytechnic University (Madrid) and Medical University of Plovdiv (Plovdiv) have suggested a new approach to studying of functional connections of brain, that enabled to find out differences between results of fMRT of healthy people and people with MDD. 85 test people passed fMRT, results of which scientists estimated from the point of view of standard group analysis and new consensus approach.

Both experiments supposed an analysis of different characteristics of functional net of brain: medium node degree (aggregation of neurons), distribution of node degrees in the net and others. While using a group approach at first for each participant there was made an individual performance calculation, and then applied a statistic analysis for searching similarities and differences. In contrast to that consensus approach demanded less efforts: for each experimental group there was made one general specific functional net with connections, that are common to 95% of participants and then characteristics were calculated and compared straightly for each net. Thus, while using common group approach you have to apply additional methods, whereas in consensus approach differences between healthy and ill people are obvious directly from calculated net characteristics.

Complex use of group and consensus approach potentially can enable to create a system of automatic recognition of MDD on the base of fMRT.

“We have obtained wider diapason of parameters that enabled to find differences between ill and healthy people, and that makes diagnosis of the disease significantly easier”, – tells a participant of the project supported by the grant of RSF, Andrey Andreev, senior research scientist of Baltic center Neurotechnologies and Artificial Intellect of Immanuel Kant Baltic Federal University.