LOS ANGELES, July 5 (UPI) -- Depression in multiple sclerosis patients may be biological rather than a psychological reaction to the burdens of being ill, U.S. researchers suggest.
Their study, published in Biological Psychiatry, finds multiple sclerosis patients are more likely than healthy patients to have brain atrophy -- shrinkage -- in three areas of the brain involved in mood and memory tissues known as the hippocampus.
Moreover, the glandular system that responds to stress and regulates other physiological processes known as the hypothalamic-pituitary-adrenal axis was more likely overactive.
"Interestingly, this idea of a link between excessive activity of the hypothalamic-pituitary-adrenal axis and reduced brain volume in the hippocampus hasn't received a lot of attention, despite the fact that the most consistently reproduced findings in psychiatric patients with depression -- but without MS -- include hyperactivity of the hypothalamic-pituitary-adrenal axis and smaller volumes of the hippocampus," Dr. Nancy Sicotte of the University of California, Los Angeles, said in a statement.
The senior study author and her colleagues used brain imaging on 29 patients with relapsing remitting multiple sclerosis and compared them with 20 healthy control subjects who did not have MS.