Comorbidity of depression, anxiety and bipolar disorder with heart disease among adults in Hawaii, 2000-2010

Background: There is evidence that up to 50% of cardiovascular disease patients suffer from mental illness. Recent studies suggest that (a) depression may increase the risk of cardiac mortality two to four times regardless of cardiac disease history, and (b) bipolar disorder is associated with increased coronary heart disease and cardiovascular mortality risk. Objectives: To (1) determine the associations between heart disease and mental illness (depression, bipolar disorder, and anxiety) and to (2) investigate the effects of ethnicity and the influence of age and ethnicity on these associations. Methods: This paper examines secondary data of all emergency department admissions of adult patients in Hawai'i hospitals from 2000-2010 (n=790,943). Data were stratified by age and ethnicity, and adjusted associations estimated using logistic regression. Results: The estimated adjusted odds ratios (95% confidence intervals) of any heart disease diagnosis with depression, bipolar disorder, and anxiety for adults under 65 are 2.68 (2.54-2.83), 3.59 (3.28-3.93), and 2.72 (2.65-2.79), respectively, and for adults 65+, 4.31 (3.70-5.02), 5.56 (4.14-7.47), and 3.33 (3.17-3.50), respectively. Among 18-64 year olds, associations of heart disease with depression and anxiety are significantly greater among Pacific Islanders. Conclusion: Mental illness is comorbid with heart disease among adults admitted to emergency rooms in Hawai'i, especially among younger Pacific Islanders. Although the temporal relation between the cardiac disease and mental illness is unclear, the findings are consistent with recent research showing that heart disease may be predictive of mental disorders. Emergency departments and primary care settings should carefully screen cardiac patients for mental disorders.