Stress-full life events and multiple sclerosis: A population-based incident case-control study

Aim: While sizeable evidence regarding the association between stressful-life events and multiple sclerosis (MS) disease activity (clinical and/or radiological) was previously documented, their relation to MS risk is controversial. We aimed to investigate the possible association of stressful-life events and multiple sclerosis risk after adjustment for relevant confounders in an Iranian population. Method: This was a population-based incident case-control study that recruited 547 MS cases and 1057 healthy controls between August 2013 and February 2015, Tehran. The patients were identified using the Iranian MS Society based on 2010 McDonald criteria. We used standard random digit dialing protocol for control selection. Logistic regression model was applied to estimate the odds ratios (95% CI) adjusted for physical activity, age, gender, tobacco smoking, waterpipe smoking and passive smoking. Results: While total life events number was not associated with risk of MS, homeless periods OR 3.85 (1.65–8.90), p = 0.002 as well as divorce OR 2.11 (1.24–3.58), p = 0.005 increased the risk of MS. However, marriage OR 0.59 (0.41–0.86), p = 0.006, death of ones’ dear OR 0.60 (0.44–0.82), p = 0.002 and joblessness OR 0.61 (0.41–0.91) reduced the risk of MS. Conclusion: We could not detect a statistically significant role for the total stressful life event during the last 3 years and MS diagnosis. However, there is some evidence confirming the possible role of some individual life events, i.e. divorce and periods of homelessness as potential risk factors for MS and conversely, having married as a protective factor in MS onset.