Multiple sclerosis twin study reveals distinct genetic, disease-specific, and psychometric impact on coping with critical life events.

Background: Critical life events challenge our competence to develop coping strategies. In people with multiple sclerosis (MS), the impact of genetics, disease-specific, and psychometric factors on coping strategies have not been explored to date.

Methods: In a unique cohort of 56 monozygotic twins discordant for MS, we applied comprehensive psychometric and clinical testing to measure factors influencing the psychosocial impact (including stressors and coping strategies) of a critical life event, exemplified by the COVID-19 pandemic (measured by the COVID-19 Pandemic Mental Health Questionnaire, CoPaQ). CoPaQ results were compared to an independent age- and sex-matched control cohort. We applied factor analysis, structural equation modeling, hypothesis testing, and regression models.

Results: We detected no differences in the perception of 14 CoPaQ subscales between MS and non-MS co-twins. However, compared to the independent control group, MS co-twins valued 5/14 CoPaQ subscales differently. Strong perception of pandemic-related stressors in MS co-twins was accompanied by higher HADS-Anxiety (ρ = 0.69, Hospital Anxiety and Depression Scale), HADS-Depression (ρ = 0.57), BDI-II (ρ = 0.74, Beck Depression Inventory), and MSIS-29-psychological scores (ρ = 0.58, Multiple Sclerosis Impact Scale 29). In a generalized linear mixed model, individuals who perceived pandemic-related stressors as more burdensome relied on inner resources, with a notable dependency on twinship.

Discussion: Using a unique twin approach, our study suggests that coping with critical life events is mainly driven by the genetic background. However, in people with MS, coping and the perception of stressors is further confounded by psychometric and disease-related factors.