Franz Alexander draws a distinction between classical mental illnesses and disorders of organ function related to disturbances of the autonomic nervous system. This approach disputed the prevailing notion (espoused by psychoanalysts such as Georg Groddeck) which drew no boundary between illnesses of the mind and body. Psychosomatic medicine proposes that psychic stimuli can trigger a chain of physiological responses that can affect bodily function and somatic disease. Dunbar surveys a range of physical illnesses and personality types and at first correlates personality types with diseases. Later Dunbar emphasizes the importance of emotions in disease.

Bodily diseases such as peptic ulcer and coronary artery disease are associated with psychic stimuli and personality types.

Dunbar obtains degrees in both divinity and medicine and is committed to integrating religion and science. She co-founds the Clinical Pastoral Education movement to provide clinical training to theological students and also studies religion as a unifying factor in personal life and its role in healing.