Could an irregular heartbeat increase your risk of depression? In a new study, researchers from the University Heart Center in Hamburg have identified a strong link between heart rhythm disorders and symptoms associated with depressive disorder. The findings shed further light on the suggested correlation between cardiovascular and psychiatric events. 

Previous studies have indicated a link between depressive symptoms and artrial fibrillation –– a rhythm disorder characterized by restricted blood flow, palpitations, shortness of breath, and weakness. However, general data has so far been lacking. The new study, which is published in the journal PLoS ONE, sought to investigate this link by reviewing data from the large-scale Gutenberg Health Study

The researchers looked a values from 10,000 individuals. The sample was population-based, meaning that the set was designed to represent the public at large rather than particular patients or socioeconomic subsets. In this sample, 309 individuals had been diagnosed with artrial fibrillation. 

Each subject was asked to indicate how depressed they felt on a scale of zero to 27. Whereas the average subject without artrial fibrillation scored a three, the average subject with artrial fibrillation scored a four. Although neither score can be said to warrant psychiatric intervention, the one-point difference nevertheless suggests an elevated mental burden. 

According to Richard Sloan, the Nathaniel Wharton Professor of Behavioral Medicine at Columbia University, the current study’s findings align with results from a number of similar research efforts. "It's consistent with a large and growing literature on the role that depression plays with heart disease," Sloan, who was not involved with the new study, told Reuters. “There are a great set of studies, many of which show a much stronger effect.”

Though the current study advances strong evidence of a biological connection between the two conditions, it is not yet clear precisely how they interact. One theory is that the fatigue and weakness brought on by heart rhythm disorders influences the patient’s perception of her physique and energy. It is also possible that both arterial fibrillation and depressive disorder arise from a shared, unknown condition. 

According to Sloan, the current study underscores the importance of considering psychiatric factors when evaluating cardiovascular events and disorders. Cardiologists should be aware that symptoms of depression may have significant bearing on a patient’s prognosis and treatment. "It's a serious matter and should be treated as a serious matter," he told reporters. “If you're depressed at any time –– whether after heart disease or something else –– you should treat it."

Source: Schnabel RB, Michal M, Wilde S, Wiltink J, Wild PS, et al. (2013). “Depression in Atrial Fibrillation in the General Population.” PLoS ONE 8(12): e79109. doi:10.1371/journal.pone.0079109