Cognitive Reserve Attenuates the Effect of Disability on Depression in Multiple Sclerosis.

OBJECTIVE

The current study explored the moderating role of cognitive reserve on the relationship between disability and depression in a sample of individuals in which brain pathology is thought to contribute to depression (multiple sclerosis; MS).

METHOD

Fifty-four individuals with MS were examined. Depression was measured using the Beck Depression Inventory-Fast Screen (BDI-FS). In addition to collecting demographic (education) and disease burden (Expanded Disability Status Scale; EDSS) related variables, participants completed a neuropsychological test battery and psychosocial questionnaires. Cognitive reserve (CR) was conceptualized in two ways: Fixed CR and Malleable CR. Fixed CR was measured using years of education and crystallized intelligence (Shipley Vocabulary). Malleable CR was operationalized as a composite of measures from the Cognitive Heath Questionnaire (CHQ). Two regressions on depression (BDI-FS) examining either type of cognitive reserve, EDSS, and their interactions were explored. Results: The interaction between EDSS and both conceptualizations of cognitive reserve were significant, t(50) = -2.60, p = .013, PRE = .12 (Fixed CR); t(47) = -2.02, p = .049, PRE = .08 (Malleable CR). Simple effects testing revealed the same pattern regardless of the type of cognitive reserve examined; EDSS predicted depression only in those with low cognitive reserve.

CONCLUSIONS

Cognitive reserve moderates the relationship between disability and depression in MS; disability does not appear to influence depression in those with high cognitive reserve.