This study posted by CNN talks about the link of stress levels to higher mortality levels within cancer patients. The article talks about how the management of stress effects effects how likely a cancer patient is to survive the disease.
The study was done by Lorenzo Cohen, professor of general oncology and director of the Integrative Medicine Program at The University of Texas MD Anderson Cancer Center. Cohen found that symptoms of depression among a group of patients with late-stage renal cell carcinoma were associated with an increased risk of death. The results of this study were published in the PLOS One journal.
This study shows validity because multiple other studies were conducted by other credible sources (doctors and professors concentrating in psychology) and results were all consistent in that stress influences the body's ability to fight off the disease.
The study also showed its credibilty because it provided areas where the research may be skewed or uncertainty may still remain. Researchers claim that deciphering the causation between stress and survival level is hard to figure out.