Deficits in executive function influence coping ability in people with multiple sclerosis: implications for intervention

Background: Executive function (EF) is an overarching term for the higher-order cognitive skills required for purposeful goal-directed activity. In people with multiple sclerosis (PwMS), EF is often impaired. Studies have shown that PwMS use more maladaptive coping strategies than healthy controls and this has been linked to higher depression and lower quality of life (QOL). Aim: To assess whether deficits in EF in PwMS are associated with depressive symptoms due to lack of adaptive coping ability. Method: Participants with relapsing remitting (RR) or secondary progressive (SP) MS (N = 107; 83RR, 24SP; age: M = 48.8±11.1) were assessed for EF (Symbol Digit Modalities Test, Word List Generation, Reading Span [RS], Trail Making Test [TMT], Elevator Counting with Distraction, Visual Elevator, Modified 6 Elements, Zoo Map, Action Program, self-report DEX Questionnaire [DEX-S]); coping styles (COPE); depression (Beck Depression Inventory-II); anxiety (State-Trait Anxiety Inventory); stress (Hassles Scale); and QOL (MSQOL-54). Hierarchical linear and logistical regression was used to analyse whether EF predicted coping, stress, depression, anxiety and QOL. Results: Compared with normative data, PwMS used significantly lower coping for 11 of 15 strategies. One coping strategy, behavioural disengagement, was significantly higher. Thirty-one participants were impaired on 2 or more EF tasks (≥1.5 SD from norms). A number of EF tasks predicted adaptive and maladaptive coping. The strongest predictors were the TMT and RS, each predicting 5 coping strategies. The TMT most strongly predicted behavioural disengagement (p = .001,OR = 35.2), whereas RS most strongly predicted mental disengagement (p = .004, δ R2 .074). However, the DEX-S was the best predictor of coping, predicting 8 strategies, the strongest being positive reinterpretation and growth (p < .0001, δ R2 .127). The DEX-S also predicted trait anxiety (p = .008,OR = 2.05), stress (p < .0001, δ R2 .220) and QOL (p < .0001, δ R2 .132). As expected, coping predicted stress, depression, anxiety and QOL. Conclusion: Deficits in EF, particularly those related to working memory and attention, influence adaptive coping in PwMS. Given that coping has been shown to impact mood and QOL in prior research, and in the current study, deficits in EF should be considered in interventions to enhance adaptive coping and QOL in PwMS. The DEX-S has the ability to predict coping, stress, anxiety and QOL, and may prove useful in identifying those most in need of such interventions.