There are probably many reasons why some people worsen more quickly than others. Stress is implicated in many other diseases, and without question, it plays an important role in MS.
It is clear that some patients are genetically predisposed to rapid progression of illness. Persons who have the DR-2 (DR-1 1501) gene have more severe disease than those who do not. However, Dr. Dupont in Den-mark showed 30 years ago that when patients have both the DR-2 gene and HLA-B7, they predictably have rapidly progressive disease and severe disability (malignant MS). For example, in our Florida experience, although only 7% of Cuban patients have the DR-2 gene, when they have both DR-2 and HLB-B7, they too have malignant MS.
There is no simple way of determining beforehand how an individual patient will fare during the course of MS. However, the frequency of attacks (one attack in the first year), good recovery from the attack, a small amount of disease in brain MRI scans, and recovery of a feeling of well-being are good indicators for a better outlook. Treatment has improved the outlook for all MS patients.