Personality and illness: genetic connections?

Illness is strongly influenced by genetics. Personality traits are influenced by genetics and have linkages with, at least, affective illness. Because genetics influences both personality and illness, we studied by literature review the genes that illness and personality traits share and, by office assessment, our patient population's illnesses and personality traits. This led to the following hypothesis: illness is related to more Submissive than Dominant personality trait and thus to lower norepinephrine activity. Patient affect and personality are often noted to be subdued in chronic illness, but whether from cause or effect is difficult to determine. After reviewing the literature on wellness, personality and genes, we endeavored to explore and better delineate our impressions of illness and personality relationships and to set the stage for a genetic hypothesis by using an online personality test in an ob-gyn practice to determine which traits could be used as proxies for personality trait genes. We thus confirmed our clinical impression that women with psychiatric and/or medical illness have more Submissive personality. The medical literature on gene markers shared by Submissive personality and illness in our population suggests the hypothesis that this relationship could be mediated by genetically lower neurotransmitter activity. Both norepinephrine activity and monoamine oxidase A, the enzyme controlling its catabolism, are in concert to blunt neuronal activity in such diverse states as depression, asthma, obesity, autoimmune illness, and in smokers. Conversely, norepinephrine activity is enhanced in breastfeeders and in other settings known to be related to good health. A point for possible divergence from the hypothesis is that African-Americans have enhanced norepinephrine activity yet poorer health outcomes although the effect of environmental risk factors in African-Americans is considered prominent by researchers. The possible importance of this hypothesis is that it changes emphasis slightly from one of splitting diagnoses to one of grouping them to achieve fresh insight. If we assess what is found in common in diverse illnesses of mind and body, we have yet another tool to assess causation. Although this hypothesis is offered somewhat in a boldness of spirit to take a new look at our many perplexing clinical problems, it is also offered with humility in light of the complexity with which we deal in patient care.