Neurology. 2004 Mar 9;62(5):726-9
Li J, Johansen C, Bronnum-Hansen H, Stenager E, Koch-Henriksen N, Olsen J.
Danish Epidemiology Science Centre, Department of Epidemiology and Social Medicine, University of Aarhus, Denmark
Previous studies have suggested that psychological stress may play a role in the risk of multiple sclerosis (MS), but the evidence is very limited.
To examine the association between MS and a well-defined major stressful life event: the death of a child.
In this follow-up study based on nationwide and population-based registers, all 21,062 parents who lost a child younger than 18 years from 1980 to 1996 in Denmark were included in the exposed cohort and 293,745 matched parents who did not lose a child in the unexposed cohort.
The two cohorts were followed for incident MS from 1980 to 1997.
Hazard ratios (HR) with 95% CI were calculated as the measure of association between the exposure and MS, using the Cox proportional hazards regression model.
Two hundred fifty-eight MS patients were identified (28 in the exposed cohort and 230 in the unexposed cohort).
The exposed parents had an increased risk of MS (HR 1.56, 95% CI 1.05 to 2.31), which is significant only when follow-up was at least 8 years.
The HR for definite/probable MS was 1.42 (95% CI 0.90 to 2.24).
Parents who lost a child unexpectedly had an HR of 2.13 (95% CI 1.13 to 4.03) for all MS, which is higher than that for other bereaved parents (HR 1.33; 95% CI 0.81 to 2.16).
Psychological stress may play a role in the development of MS.