As a part of recent study, researchers have found the difference between heart disease and depression. According to the findings, people with heart disease are more likely to suffer from depression, and the opposite is also true. The study also suggest that while inflammation is a natural response to fight off infection, chronic inflammation - which may result from psychological stress as well as lifestyle factors such as smoking, excessive alcohol intake, physical inactivity and obesity is harmful. The link between heart disease and depression is well documented. People who have a heart attack are at a significantly higher risk of experiencing depression. Yet scientists have been unable to determine whether this is due to the two conditions sharing common genetic factors or whether shared environmental factors provide the link.