Has there been any Scientific research conducted into relationships between stress related illnesses and?

We talked about this in psychology but I don't have any specific studies that I can show you. Stress and life expectancy does have a link, but it's not like you can directly say stress causes you to die sooner because there are other factors in there as well. Stress can cause hypertension which can weaken the heart and all that which if left untreated can lead to an earlier death. Can also cause gastrointestinal problems, like ulcers as well. So I guess gastrointestinal problems could shorten your life depending on which type of issues the person was having.