Anxiety and depression increase the risk of blood clots by 50%, says new study

Having an anxiety or depressive disorder may increase the risk of developing a serious blood clot by nearly 50 percent, a new study finds.

Brain imaging showed that increased stress-related activity in the brain, as well as inflammation caused by mental illnesses, may increase the risk of deep vein thrombosis, in which a blood clot forms in the deep veins.

Researchers at Massachusetts General Hospital in the US analysed a dataset of over 1.1 lakh participants to understand the relationship between anxiety and depression and the risk of deep vein thrombosis. A smaller group of 1,520 people underwent brain imaging.

Over a follow-up period of more than three years, 1,781 participants (1.5 percent) were found to have had blood clotting problems.

The researchers found that having either an anxiety disorder or a depression disorder increased the risk of developing deep vein thrombosis by about 50 percent, while having both mental illnesses increased the risk of developing a clotting problem by 70 percent.

“The results, thus, identify anxiety disorders and depression as potent risk factors for deep vein thrombosis and identify modifiable mechanisms that mediate this association,” the authors wrote in the study published in the American Journal of Hematology.

The average age of the participants was 58 years and 57 percent of them were women. Of the entire group, 44 percent had a history of cancer.

However, the authors said that adjusting for cancer (which is a risk factor for both depression and venous blood clots) did not change the results.