Researchers at the prestigious Peter McCallum Cancer Centre in Melbourne have previously shown that optimism (a general belief that things will work out for the best, being positive, etc) did not improve survival from inoperable lung cancer.
This caused quite a stir, as many of us in the profession believe that our emotional state and outlook profoundly influence outcome from illness. In fact, the lack of survival benefit may have been the result of the fact that they chose to study optimism rather than hope.
Hope is a different concept; it is about having the will to take action to get better outcomes, to look at available alternatives and be prepared to embrace them, essentially to realistically take control of the illness.
The same researchers, now investigating hope, as part of a large randomized controlled trial of different chemotherapy regimens in advanced bowel cancer, found that hope did indeed improve survival, and conversely that depression decreased survival time.
This fits with the thrust of this website; it is very likely that embracing lifestyle changes that enhance health, taking positive steps to avoid depression, and taking control of the illness, result in considerably better outcomes for people with MS.