AIDS: Psychoneuroimmunology (PNI) focuses on the connection between the mind and the body. This area of investigation concentrates on ways in which the mind and brain communicate with the immune system. U.S. psychologists, George Solomon and Robert Ader, demonstrated in animals that tension can damage immune functions. Today, immunologists, micro-biologists and endocrinologists are studying this relationship. The brain and immune system communicate in two principle ways: by means of hormones which the brain regulates, and nerve fibers which communicate with immune cells. Extreme tension can alter the function of immune cells. Immunological alterations can be associated with areas of stress. Some experimental interventions which increase the ability to deal with tension stimulate certain immunological processes. For example, helping individuals develop problem-solving techniques has increased certain immunological functions in persons with AIDS and cancer. How a person understands his own emotions can affect the immune system, as well as the extent of social support he receives. The study of PNI is part of a multidisciplinary effort to determine if psychological factors have an impact on health due to their effect on the immune system.