Revisiting cognitive reserve and cognition in multiple sclerosis: A closer look at depression.

ABSTRACT

BACKGROUND: The protective effect of cognitive reserve (CR) on cognition in people with multiple sclerosis (PwMS) has been well described. OBJECTIVE: To explore the relationship between aspects of CR, namely, leisure pursuits and depression. METHODS: In a cross-sectional study, a sample of 155 PwMS and 115 healthy controls (HC) underwent cognitive testing with the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. Leisure activity was retrospectively recorded using the Leisure Activity Scale (LAS). Depression was assessed using the Hospital Anxiety and Depression Scale. RESULTS: PwMS demonstrated greater decreases in leisure activity over time compared to the HC group, particularly in the past year ( p < 0.001). Here, depression accounted for 17% of the variance in determining the level of leisure activity ( p < 0.001). Premorbid IQ and leisure activity within the past year emerged as significant predictors of information processing speed, learning, memory and executive function. After controlling for depression, the influence of leisure activity on cognition was insignificant. CONCLUSION: Depression can cause significant changes in behaviour which can influence indices of CR, such as leisure pursuits. Successfully treating depression may lead to a more active lifestyle thereby offsetting in part the cognitive burden of disease.