Psychoneuroimmunology (PNI)

It has been shown that the brain may influence the response of the immune system, so that mental states may inhibit the body's resistance to disease; and that there is equally an influence from the immune system to the brain, so that hormones can effect the state of mind. PNI has demonstrated that there is a shared consciousness in mind and body; medical and social sciences combine to treat the two together, emphasizing that not only can mental states cause disease but can also be effective in producing positive health - a serene mental state can act therapeutically on disease. For example, it has been demonstrated that psychological states can alter the concentration of the cells used by the body to fight viruses and tumours.