People who experience symptoms of depression are more likely to go on to develop heart disease or suffer a stroke than those who report good mental health, according to research we part-funded and published today in JAMA.
Researchers at the University of Cambridge analysed the health records of over half a million people, with no prior history of heart and circulatory disease, who were enrolled to two different studies: UK Biobank (2006-2010) and the Emerging Risk Factor Collaboration (ERFC; 1960-2008).
Upon joining the studies, participants were given a score based on questionnaires assessing their mood and any symptoms of depression that they had experienced over the previous one to two weeks. These scores were divided into five groups based on increasing severity of symptoms.
Now, over 10 years later, researchers have found that those in the highest scoring group, and with most severe symptoms of depression, were more likely to have since developed heart disease or to have had a stroke, compared to people with the lowest scores.
The increased risk is small
In the UK Biobank cohort of 401,219 participants, there were 21 cases of heart disease per 1000 people across 10 years in those with the highest scoring group vs 14 cases of heart disease per 1000 people in the lowest scoring group. There were 15 strokes per 1000 people over 10 years in those in the highest scoring group and 10 strokes per 1000 people in those with the lowest scores.
This means an extra seven cases of heart disease and five strokes per 10,000 people would be expected in one year for those with higher symptoms of depression. Similar results were found in the ERFC cohort of 162,036 people from 21 different studies across Europe and North America.
The higher risk for heart disease and stroke existed even after risk factors for heart and circulatory diseases, such as age, sex, smoking status, history of diabetes, blood pressure, body mass index, and cholesterol levels, were accounted for.
The researchers point out that symptoms of depression were only measured when each individual joined the study. This means the scores don’t necessarily reflect a person’s feelings across the entire time they were part of the study.
Professor Emanuele Di Angelantonio, BHF-funded researcher at the University of Cambridge, said:
“This is the largest evidence to date that feelings related to depression are associated with a person’s chance of having heart disease or stroke in the future.
“The observed higher risk is small in magnitude and these results are just one piece of the puzzle. We now need to do more research to understand whether these observed associations are causal and the possible biology behind this link.”
Findings should not cause concern
Professor Sir Nilesh Samani, our Medical Director, said:
“Our mental and physical health go hand-in-hand. It’s clear from this research that our hearts and minds are more connected than we previously thought. By exploring this link further, we may find new ways of helping to improve our heart health.
“However, it is important to stress that the increased risk is modest and observed over a long period of time. It should not alarm those currently experiencing low mood or feelings of depression about their immediate heart health.”
This study was also supported by the National Institute for Health Research (NIHR) and Health Data Research UK (HDRUK).
