MS is unpredictable

Dutch researchers followed 73 patients with relapsing-remitting multiple sclerosis.

They found during periods of stress patients were twice as likely to develop new symptoms, or a more severe form of their existing symptoms.

The reason for the apparent link is unclear, although it is possible that stress triggers the release of hormones that affect the immune system.

We often hear anecdotal evidence that bereavement and family problems, for instance, are linked to relapses Mike O'Donovan, MS Society

The finding suggests that giving people with MS coaching on how to deal with stress may help to delay the development of symptoms.

Researcher Dr Rogier Hintzen, a neurologist at the Erasmus Medical Centre in Rotterdam, said: "The knowledge that stressful events are associated with disease activity adds important information to the limited insight that patients and their caregivers have on this unpredictable disease."

Auto-immune disease

MS is caused by a malfunctioning of the immune system, which attacks the coating of the nerves.

Symptoms include tingling, fatigue, loss of balance and slurred speech.

The majority of patients experience periods when their symptoms become worse, followed by periods of stability.

However, there has been much debate about just what role, if any, psychological stress plays in determining the progression of the disease.

Christine Jones, chief executive of the MS Trust, said: "People with MS often say that their symptoms worsen after stressful life events, so we welcome this new research.

"If we can understand any connection between stress and MS, it may shed light on the disease mechanism, which is still poorly understood."

Her view was echoed by Mike O'Donovan, chief executive of the MS Society, who said: "We often hear anecdotal evidence that bereavement and family problems, for instance, are linked to relapses."

However, he stressed that more research was needed before firm conclusions could be drawn.