People who have fewer bouts of depression could be more than a third (34 per cent) less at risk of having blocked arteries, new research suggests.
They also have a 33 per cent lower risk of type 2 diabetes, regardless of lifestyle factors like diet and exercise, and their genetic risk.
Researchers suggest the prevalence of unrecognised depression in patients with heart disease has been known for more than 40 years.
However, it is unclear whether depression contributes to the development of heart disease.
According to the experts, the findings may have implications for improving the health of people with the conditions. But future research is needed to determine the cause of the observed associations and to identify potential implications for preventive treatments.
Pradeep Natarajan, of Massachusetts General Hospital, Boston, and colleagues studied the complete DNA of 328,152 people of European ancestry (aged between 40 and 69) available in the UK Biobank database.
Using this data they were able to create a specialised tool that can be used to refine risk prediction for heart disease.
The researchers found that having fewer depressive episodes was associated with a decreased risk of coronary artery disease, type 2 diabetes and irregular heartbeat by 34 per cent, 33 per cent and 20 per cent, respectively.
According to the study, the association was independent of lifestyle factors known to be associated with both poor mental health and the risk of developing cardiovascular disease, such as diet, exercise and smoking.
The researchers also found the association between depression and coronary artery disease was higher in women than in men.
Writing in Nature Cardiovascular Research, the study authors said: “The findings of this study may have implications for improving individual – and population-level cardiometabolic health.”
