How a Concussion Can Lead to Depression Years Later
COLUMBUS, Ohio – A head injury can lead immune-system brain cells to go on “high alert” and overreact to later immune challenges by becoming excessively inflammatory – a condition linked with depressive complications, a new animal study suggests.
The findings could help explain some of the midlife mental-health issues suffered by individuals who experience multiple concussions as young adults, researchers say. And these depressive symptoms are likely inflammation-related, which means they may not respond to common antidepressants.
An added complication is that aging already increases brain inflammation. So on top of normal aging concerns, people who have had a traumatic brain injury (TBI) experience added inflammation caused by magnified immune responses to so-called “secondary challenges,” such as a second head injury, infections or other stressors.
In mice, these high-alert cells in the brain – called microglia – had an exaggerated response to an immune challenge one month after a moderate brain injury. This increased brain inflammation corresponded with the development of depressive behaviors that were not observed in uninjured mice.
more
http://researchnews.osu.edu/archive/tbidepress.htm
