Does stress cause MS? Study says no

[ActiveMSers]

No one wants stress, and there has been some association between stress and relapses in multiple sclerosis. But does stress potentially cause MS? A recent study that looked at 237,000 female nurses says no. - Dave

May 31, 2011 -- Leading a stressful life isn't likely to raise the risk of developing multiple sclerosis (MS), according to a new study.

Researchers say exposure to stress has long been suspected to play a role in aggravating existing MS, but it has not been previously established whether stressful life events could increase the risk of developing MS.

"This rules out stress as a major risk factor for MS," researcher Trond Riise, PhD, of the University of Bergen, Norway, says in a news release.

Full Article:
http://www.webmd.com/multiple-sclero...ked-to-ms-risk

[ActiveMSers]

Here's a more detailed article that was sent to me. - Dave


Stress Does Not Increase Risk for Multiple Sclerosis

Fran Lowry

June 2, 2011 — Stress does not appear to play a major role in the development of multiple sclerosis (MS), the results of a new study suggest.

The finding is contrary to some earlier studies that have shown a link between stressful life events and subsequent development of the disease, lead study author Trond Riise, MD, from the University of Bergen, Bergen, Norway, and his colleagues write.

"We have known that stressful life events have been shown to increase the risk of MS episodes, but we weren't certain whether these stressors could actually lead to developing MS itself," Dr. Riise told Medscape Medical News. "The topic has been of high interest for many years, particularly among patients, but there are very few studies on this topic.

"Our results do not support a major role of stress in the development of the disease," Dr. Riise said. "But, while our data do not give support to such an association, we believe that new studies are still needed for more definite answers."

The report was published in the May 31 issue of Neurology.

Nurses' Health Study

Dr. Riise and his associates studied 2 cohorts of female nurses participating in 2 prospective studies of female registered nurses living in the United States — the Nurses' Health Study (NHS) and the Nurses' Health Study II (NHS II).

The NHS was begun in 1976 and recruited 121,700 nurses aged 30 to 55 years. The NHS II was started in 1989 and recruited 116,671 nurses aged 25 to 42 years.

The participants were asked to report if they experienced general stress at home and at work, including physical and sexual abuse in childhood and as teenagers.

After adjusting for age, ethnicity, latitude of birth, body mass index at 18 years of age, and smoking, the study found that severe stress at home did not increase the risk of developing MS (hazard ratio, 0.85; 95% confidence interval [CI], 0.32 – 2.26).

There was no significantly increased risk for MS among women who reported severe physical abuse during childhood (odds ratio [OR], 0.68; 95% CI, 0.41 – 1.14) or adolescence (OR, 0.77; 95% CI, 0.46 – 1.28) or among women who reported they had been forced into sexual activity as children (OR, 1.47; 95% CI, 0.87 – 2.48) or as teenagers (OR, 1.21; 95% CI, 0.68 – 2.17).

Dr. Riise noted that the findings from the study might generate some controversy, especially among patients who believe their disease has been caused by stress. "Many patients believe that stress has played an important role in the development of their disease, and this has been an established knowledge that lacked scientific support," he said.

His hope is that the results of the study will help put patients' minds at rest. "MS patients should not feel guilty for having put themselves under stress out of misplaced thinking that they have caused their disease," he said.

Complex Interaction

Commenting on this study for Medscape Medical News, Gary Birnbaum, MD, director of the Multiple Sclerosis and Research Center in Golden Valley, Minnesota, said, "While stress can cause neuroendocrine changes, and thus result in alterations in immune function, it is not surprising that stress per se is unable to induce MS."

A complex interaction of genes and environment is believed to be essential for the development of MS, he noted. "While stress could allow environmental factors to have an undue, detrimental effect, the data presented in this paper do not support this."

Dr. Birnbaum added that the implications of the observations in this study have important medicolegal ramifications.

Litigation has resulted from instances where persons have been involved in accidents and then subsequently developed MS. A cause-and-effect relationship has been espoused but now would be more difficult to defend.

"Litigation has resulted from instances where persons have been involved in accidents and then subsequently developed MS. A cause-and-effect relationship has been espoused but now would be more difficult to defend," he said.

An association between stress and disease exacerbation also is problematic, he said.

"While stress can clearly cause a worsening of symptoms, there are few well-controlled, biologically verified studies, for example, with MRI [magnetic resonance imaging], showing that stress in isolation results in increased central nervous system inflammation that is the hallmark of an MS relapse.

A recent systematic review of this issue in the February 2011 issue of Neuroepidemiology supports this contention, he added.

The current study is an "interesting and important paper, mainly because of the large numbers of study participants, its prospective accumulation of data, and the implications of their [the authors'] findings," Dr. Birnbaum concluded.

Dr. Riise and Dr. Birnbaum have disclosed no relevant financial relationships.

Neurology. 2011;76:1866-1871. Abstract