A major scientific project in Europe, called TO_AITION, has just finished in December 2025. The project aimed to understand why heart disease and depression often occur together in the same people.
Scientists have long known that these two serious conditions are connected, but they didn’t fully understand how. This project is helping to change that.
Heart disease is the top cause of death in the world. In Europe alone, over 10 million people develop heart disease every year. It causes more than 3 million deaths each year in European countries. At the same time, depression affects more than 300 million people around the world.
People with depression are two to three times more likely to develop heart disease. In fact, one in three people with heart disease also has depression. After a serious heart problem like a heart attack, one in two people may develop depression.
Dr. Evangelos Andreakos, who leads the TO_AITION project, said that the biological connection between heart health and mental health has been ignored for too long. He and his team wanted to change that by studying the shared causes and processes inside the body that lead to both conditions.
The researchers believe that the root cause is a kind of long-term, low-level inflammation in the body. This inflammation may be caused by the immune system being trained over time by genetics, lifestyle, or the environment. This “trained immunity” could create a state of ongoing inflammation, which then raises the risk for both heart disease and depression.
To explore this idea, the TO_AITION project brought together 14 research organizations from across Europe, including the European Society of Cardiology.
They studied large groups of people and collected data on their biology, including information about proteins, DNA, gut bacteria, and more. They also used advanced computer modeling to look for patterns and shared biological pathways.
The scientists found several biological markers—proteins, fats, RNA, and DNA changes—that were linked to both depression and heart disease. These markers can help doctors spot people at risk. The project also developed early versions of tools, like a lab-on-a-chip test and a digital platform, to predict who is most at risk and help guide treatment.
One of the biggest milestones was showing off a new web-based tool called the TO_AITION Cloud Risk Stratification Platform. This platform was presented at the European Society of Cardiology Congress in Madrid in August 2025.
It’s made to help doctors and mental health professionals work together to diagnose and manage patients with both heart disease and depression. The tool could also be useful for researchers and companies making new treatments.
Another success of the project was a scientific paper linking the genetic causes of major depression and artery disease. It showed that the same genes may cause problems in the blood, brain, and heart, explaining why the two illnesses often appear together.
In summary, the TO_AITION project found strong evidence that low-level inflammation in the body plays a key role in causing both heart disease and depression.
This means that treating inflammation or preventing it might help stop both diseases from developing together. The project also gave doctors new tools and information to spot people at risk earlier and provide better, more personalized treatment.
Dr. Andreakos believes this work can change the way we think about these two major health problems. Instead of just treating symptoms, the goal now is to break the cycle of disease by understanding and targeting the causes.
The project also hopes to raise awareness about the close connection between heart and mental health, so patients, doctors, and decision-makers can act sooner and more effectively.
The findings can be found in medRxiv.
Copyright © 2025 Knowridge Science Report. All rights reserved.
