EurekAlert! -- Which comes first, depression or inflammation? To help solve this long standing chicken and egg conundrum, researchers led by Jesse Stewart, Ph.D., assistant professor of psychology at Indiana University-Purdue University Indianapolis asked two critical questions. Does depression lead to elevated inflammatory proteins in the human body? Or does an increase in these proteins lead to depression? They found that the answer to the first question appears to be “yes,” and the answer to the second question may be “no” among healthy adults.