Background: Personality traits are reported to be associated with a variety of medical comorbidities. Correlational studies report an association between 'bearing grudges' and medical conditions. We hypothesize persons reporting "bearing grudges for years" would be more likely to have medical comorbidities and test this hypothesis in an epidemiological sample.
Methods: The National Comorbidity Survey Replication is a probability sample of the US population designed to constitute a nationally representative sample (N = 9,882). Associations were measured in odds ratios (95% CI) and adjusted using logistic regression. Confounders included: gender, age, race, and smoking status. We tested the hypothesis on 14 following medical conditions: heart disease, high blood pressure, history of heart attack, asthma, diabetes, cancer, epilepsy, arthritis, neck problems, headaches, stroke, and ulcers. Significance levels were adjusted for multiple comparisons using the Bonferoni procedure.
Results: Positive and statistically significant associations were found, after adjusting for confounders and correcting for multiple comparisons, between bearing grudges and history of heart attack (odds ratio 2.1, 95% CI 1.5-2.9) and disease (1.6, 1.2-2.2); high blood pressure (1.5, 1.3-1.7), stomach ulcers (1.6, 1.3-1.9); arthritis (1.5, 1.3-1.9); back problems (1.6, 1.4-1.8); headaches (1.8, 1.6-2.1); and chronic pain (1.7, 1.4-2.1). No association was found with history of asthma, diabetes, epilepsy, allergies, stroke, and cancer.
Conclusions: In a population-based survey, bearing grudges is associated with a history of pain disorders, cardiovascular disease, and stomach ulcers. These results point to the importance of psychosomatic research in medical settings.