Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Multiple Sclerosis Health Center

Font Size

Stress, Violence May Make MS Worse

Bullying Makes Viral Infection, Multiple Sclerosis Worse in Mice
WebMD Health News
Reviewed by Louise Chang, MD

Aug. 17, 2007 -- Mice with an MS-like disease got sicker faster after being chased and bitten by aggressive mouse bullies.

MS -- multiple sclerosis -- is an autoimmune disease in which the immune system attacks the myelin sheath protecting nerve cells. Nobody knows exactly what triggers recurrent relapses and new brain lesions in people with MS. There's some evidence that stress plays a role.

To investigate this issue, psychologist Mary W. Meagher, PhD, and colleagues at Texas A&M University infected young male mice with a virus that eventually triggers MS-like autoimmune responses. Three of these mice were housed in a cage. Over several weeks, they established a stable social hierarchy.

Meanwhile, the researchers selected a number of older, more aggressive mice. These bully mice were chosen because they were quick to attack other mice.

Two hours a night, three nights in a row, one of these mouse bullies was put in the cage with the younger, virus-infected mice. After a night off, the infected mice underwent another three nights of harassment by the bully mice. To prevent social bonding, a different bully mouse was used for each session.

The mouse "intruders," Meagher and colleagues note, engaged in "observable aggressive behaviors" -- "posturing, fighting, wounding, and pursuit."

Sure enough, the stress got to the virus-infected mice. Their immune systems were less able to fight off illness than mice that had not been bullied. And their MS got worse, faster, than the MS of less stressed mice.

"Similar to mice exposed to repeated social defeat by an aggressive intruder, people exposed to chronic social conflict experience high levels of stress and consequent dysregulation of the immune system, thereby increasing vulnerability to infectious and autoimmune disease," Meagher says in a news release.

Meagher and colleagues presented their findings at the annual meeting of the American Psychological Association, held Aug. 17-20 in San Francisco.

Today on WebMD

nerve damage
Learn how this disease affects the nervous system.
woman applying lotion
Ideas on how to boost your mood and self-esteem.
woman pondering
Get personalized treatment options.
man with hand over eye
Be on the lookout for these symptoms.
brain scan
worried woman
neural fiber
white blood cells
sunlight in hands
marijuana plant
muscle spasm