Do positive or negative stressful events predict the development of new brain lesions in people with multiple sclerosis?

Background. Stressful life events have long been suspected to contribute to multiple sclerosis (MS) disease activity. The few studies examining the relationship between stressful events and neuroimaging markers have been small and inconsistent. This study examined whether different types of stressful events and perceived stress could predict the development of brain lesions. Method. This was a secondary analysis of 121 patients with MS followed for 48 weeks during a randomized controlled trial comparing stress management therapy for MS (SMT-MS) to a waitlist control (WLC). Patients underwent magnetic resonance imaging (MRI) scans every 8 weeks. Every month, patients completed an interview measure assessing stressful life events and self-report measures of perceived stress, anxiety and depressive symptoms, which were used to predict the presence of gadolinium-enhancing (Gd+) and T₂ lesions on MRI scans 29-62 days later. Participants classified stressful events as positive or negative. Negative events were considered 'major' if they involved physical threat or threat to the patient's family structure, and 'moderate' otherwise. Results. Positive stressful events predicted decreased risk for subsequent Gd+ lesions in the control group [odds ratio (OR) 0.53 for each additional positive stressful event, 95% confidence interval (CI) 0.30-0.91] and less risk for new or enlarging T₂ lesions regardless of group assignment (OR 0.74, 95% CI 0.55-0.99). Across groups, major negative stressful events predicted Gd+ lesions (OR 1.77, 95% CI 1.18-2.64) and new or enlarging T₂ lesions (OR 1.57, 95% CI 1.11-2.23) whereas moderate negative stressful events, perceived stress, anxiety and depressive symptoms did not. Conclusions. Major negative stressful events predict increased risk for Gd+ and T₂ lesions whereas positive stressful events predict decreased risk.