Faced with a specific situation of stress, cardiac activity increases, breathing becomes agitated, sweating appears in the hands and the mouth becomes dry. But w hen stress is continued things can get worse and lead to depression. Scientists from the University of Washington (USA) present today in Nature the molecular mechanism that explains the link between a situation of chronic stress and depressive disorders. It is a peptic called corticotropin-releasing hormone (CRH) , which is synthesized in the stressed brain and affects the release of dopamine in the nucleus accumbens , a region of the brain related to motivation, reward, pleasure and enjoyment. social behavior .
Under normal circumstances, when something exciting or motivating happens to us, or when an event piques our curiosity, CRH binds to a receptor in the brain and triggers the release of dopamine, which makes us feel good. However, when stress is prolonged in time, this mechanism fails, dopamine is no longer released and, altering the chemical cascade that gives us the feeling of well-being and pleasure, everything that surrounds us is no longer interesting. Researchers have calculated that the effect lasts for around three months after a stress episode, and that it explains why it can lead to depression.
