The commonest and best-documented association of personality type and disease is the higher risk of cardiovascular disease in personality Type A. Type A persons are driven, less self-forgiving, impatient, compulsive and energetic. As a result of their emotions, they experience higher circulating levels of stress hormones (such as cortisol) than do others. The stress hormones have an adverse effect on the cardiovascular system, raising the risk of hypertension and cardiac events.
By contrast, Type B personalities are laid back, relaxed, and go about life at a slower, more leisurely pace. They are unfazed by small problems or life’s difficulties and, as compared to Type A, are at much less risk for heart problems.
Type C (cancer-prone) personalities respond to stress with depression and hopelessness. They are thought to have a higher risk of cancer mortality for two reasons: 1. They may have a higher incidence of smoking, and 2. They may have less spirit to emotionally fight cancer once it occurs, and therefore experience poorer survival.
Type D (distressed) personality, like Type A, has a higher incidence and severity of heart disease. These people have frequent negative emotions and inhibit them. They also avoid social contact. They are subject to major depression and experience elevated levels of cortisol. Both depression and elevated cortisol are proven risk factors for cardiovascular diseases.
In summary, Type A and Type D personalities are at increased risk for cardiovascular disease. Type C personalities may have increased cancer mortality. Type B personalities seem to have less disease risk than the others.