Scientists cannot yet say exactly which processes at the cellular level lead to depression, but they confidently assert that the brain of a depressed person, even in a calm state, is subject to overload. This is due, first of all, to the fact that the signals between the subcortical and limbic regions of the brain during depression travel a much longer path than in a normal, cheerful state. Their intensity also changes.
The new discovery explains the earlier statements of many American scientists that frequent depression is the cause of the development of senile dementia, often turning into Alzheimer’s syndrome and other unpleasant diseases. During depression, the limbic and subcortical regions of the brain begin to exchange chaotic signals through the intermediate regions, according to data from two independent studies. And this, in turn, leads to wear and tear of neural networks. As you know, neurons in the human brain communicate with each other through synapses, tiny structures that connect nerve cells and transmit signals. Back in the 20th century, it was proven that stress has an extremely negative effect on the state of synapses, but the effect of depression on the nervous system has been studied not so long ago. Two independent researchers – Andrew Lutcher from the University of California and Shukyao Yao from the Central Southern University of China (Hunan province) – have confirmed that there are significant differences in the brain function of depressed people compared to healthy people. Andrew Lutcher and his colleagues found that the subcortex and limbic regions of the brain, which are usually involved in processing our emotions, begin to communicate intensively with each other with streams of neural signals during depression. The researchers note that these signals affect the brain like white noise and only increase depression, preventing the person from thinking about how to stop being sad and start moving on. The Chinese scientist Shukyao Yao in his study emphasizes that in depression, the most difficult situations arise when the patient is prone to long-term reflection. This creates in his brain the act of continuous reproduction of negative thoughts, which, in addition to overloading neural networks, disrupt the activity of the hippocampus associated with the storage of long-term memory. And this, in turn, can already lead to more serious neurological disorders, as well as to complete or partial memory loss. The practical implications of research Long-term depression can cause serious neurological and mental disorders, so either do not fall into depression at all, or look for a way out and interesting activity at the first signs of it. This will help preserve neural networks and avoid memory problems in old age.