What are general concepts that led to the idea of A, B, C and D personality types correlating with specific disease risks?

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.