A study conducted on rats, published in the Proceedings of the National Academy of Sciences, proved that depression in cancer patients might be caused by the tumour itself, as opposed to a response from stress brought on by the disease.
According to the U.S. National Cancer Institute, approximately 15 to 20% of patients who have received a cancer diagnosis exhibit symptoms linked to depressive disorders.
Scientists remarked that the rodents who had cancer were less motivated to escape when forced to swim. They also refused to drink sugared water, a delicacy they typically enjoy.
In addition, Dr. Brian Prendergast’s team at the University of Chicago discovered that the rats had higher levels of corticosterone, a stress hormone.