People with an irregular heartbeat are at higher risk of being depressed, suggests a new study from Germany, Newsmax Health reports.

Atrial fibrillation (AF) is a type of rhythm disorder affecting the heart's upper chambers. It can be caused by a number of issues - including heart attacks, infections and heart valve problems. Obesity is a risk factor for AF, as are high blood pressure, high cholesterol and diabetes.

Doctors have long known that patients' mental state can affect how well they take care of themselves, follow treatment instructions and how they perceive the burden of their illnesses.

Dr. Renate Schnabel, from the University Heart Center in Hamburg, and her fellow researchers wanted to see if depression might affect the course of atrial fibrillation and patients' feelings about their disease.

Schnabel's team used data on 10,000 German adults for the new study. Most did not have AF, but 309 did.

The researchers compared the average depression scores for people with AF to the scores of people without the condition.

Depression was measured on a scale of zero to 27, with higher scores indicating more severe depression.

On average, people with AF scored a four, compared to an average score of three among those without the irregular heartbeat. 

 Screening for and treating depression symptoms might help heart patients to feel better physically and potentially even improve their heart conditions.