Studies suggest that depressive disorders or depression in humans occur because of the modifications in the activities and connectivity of brain systems on primary rewards and memories.
The findings, which were published in the journal ‘Biological Psychiatry: Cognitive Neuroscience and Neuroimaging’, provided answers as to which parts of the brain could be at the verge of symptoms of reduced happiness and pleasure, or negative memories in the case of depression.
To reach this study, the researchers applied a new approach on which it measured one region of the brain with another, most commonly known as effective connectivity, in depression.
The approach goes beyond the limitations of previous brain imaging studies which show the activity of different brain regions is more or less related.
Edmund Rolls, Professor at University of Warwick in England, one of the professor in the research, said, “The new method allows the effect of one brain region on another to be measured in depression, in order to discover more about which brain systems, make causal contributions to depression.”
The research compared 336 people with major depressive disorder to 350 people who were controllably healthy.
The study showed that brain regions involved in reward and subjective pleasure received less or reduced effective connectivity in patients with depressive disorders which contribute to decreased feeling of happiness.
Increased brain activity was studied in those brain regions where punishment and responses to a reward were not received.
Memory-related areas of the brain in depressed people had an increased activity, which, according to the researchers, might be related to heights of memory processing or possibility of unpleasant memories.
Rolls said, “These findings are part of a concerted approach to better understand the brain mechanisms related to depression, and thereby to lead to new ways of understanding and treating depression.”