Autoimmune Diseases and Infections Associated With Increased Risk of Subsequent Mood Disorder

Autoimmune diseases and infections appear to be risk factors for subsequent mood disorder diagnosis, according to a study by Michael E. Benros, M.D., of Aarhus University, Denmark, and colleagues.

A total of 91,637 people born in Demark between 1945 and 1996 were found to have visited a hospital for a mood disorder.  Researchers found a prior hospital contact because of autoimmune disease increased the risk of a subsequent mood disorder diagnosis by 45 percent. Any history of hospitalization for infection increased the risk of later mood disorders by 62 percent. Approximately one-third (32 percent) of the participants diagnosed as having a mood disorder had a previous hospital contact because of an infection, whereas 5 percent had a previous hospital contact because of an autoimmune disease, the study finds.

“Autoimmune disease and the number of severe infections are independent and synergistic risk factors for mood disorders, with hospital-treated infections being the most common risk factor…these associations are compatible with the hypothesis of a general immunologic response affecting the brain in subgroups of patients with mood disorders,” the study concludes.

(JAMA Psychiatry. Published online June 12, 2013. doi:10.1001/jamapsychiatry.2013.1111.