Читать книгу The Sickening Mind: Brain, Behaviour, Immunity and Disease - Paul Martin - Страница 20

In this struggle Tarrou’s robust shoulders and chest were not his greatest assets; rather, the blood which had oozed under Rieux’s needle and, in this blood, that something more vital than the soul, which no human skill can bring to light.

Albert Camus, The Plague (1947)

We turn now to a less visible, but no less important, mechanism by which the mind and body interact to affect health: the immune system. Among the most important developments in recent years has been the discovery of numerous biological pathways connecting the brain with the body’s defence and regulatory mechanisms. Through these pathways the biological system that underlies our thoughts, emotions and behaviour – the brain – can exert a pervasive influence on the biological system that defends the body against most forms of disease – the immune system.

Our physical health depends critically on how well our immune system is functioning. One reason why a person suffering from psychological stress is more susceptible to colds and infections is because their immune system is less able to resist when they are exposed to disease-causing viruses or bacteria. In the following chapters we shall be exploring the manifold ways in which the mind and immune system affect each other. But before we do this we need to clarify a few basic issues.

So far I have referred rather sweepingly to the mind’s effect on the immune system, as though the immune system were a homogeneous entity whose activities could be measured in a simple way, like temperature or blood pressure. In reality, the immune system is a breathtakingly complex and subtle entity whose intricate workings are still far from being fully understood. Immunology is one of the branches of science that has made the most spectacular leaps in understanding over the past thirty years, but it still has a very long way to go. To unravel how the mind influences physical health we must first establish what the immune system does and how it works.