Is there a combined effect of depression and cognitive reserve on cognitive function? Findings from a population-based study

Abstract

Objective

To analyse the combined effect of depression and cognitive reserve (CR) on cognition over a three-year follow-up period; and to explore this relationship specifically in individuals aged 65+ years.

Design

Data from the ‘Edad con Salud’ project were analysed (n = 1,144; 50+ years).

Main Outcome Measures

The Composite International Diagnostic Interview was used to evaluate depression. CR was assessed with the Cognitive Reserve Questionnaire. Episodic memory was assessed with the word list memory and recall. Verbal fluency was measured through the animal naming task. Random coefficient regression analyses were performed.

Results

Depression was associated with lower scores in episodic memory, whereas increased levels of CR were related with higher scores across all the cognitive tests. Among older-aged individuals, cognition decreased at lower levels of CR regardless of depression, while participants with depression exhibited decreased values in both measures of memory at higher levels of CR.

Conclusion

Depression and CR were related with cognitive performance. Among older individuals, those with low levels of CR may constitute a vulnerable group with poor cognitive prognosis, whilst a harmful effect of depression on memory performance was observed among individuals with greater CR. Further evidence needs to be gathered to understand these associations.

Keywords:

• Cognitive reserve
• depression
• cognition
• population-based study

Acknowledgements

Our deepest appreciation to all participants for their generous contribution, which made this work possible. EL’s work is supported by the Sara Borrell postdoctoral programme (CD18/00099) from the Instituto de Salud Carlos III (Spain) and co-funded by European Union (ERDF/ESF, ‘Investing in your future’). NMM’s work is supported by the programme ‘Contratos predoctorales para Formación de Personas Investigador, FPI-UAM’, from the Universidad Autónoma de Madrid. BO’s work is supported by the PERIS program 2016–2020 ‘Ajuts per a la Incorporació de Científics i Tecnòlegs’ (grant number SLT006/17/00066), with the support of the Health Department from the Generalitat de Catalunya.

Disclosure of interest

JMH is consultant of Elli Lilly and Co, Roche, and Lundbeck. None of these activities are related to the current project. For the remaining authors, none was declared.

Data availability statement

Data not available due to legal restrictions.

Additional information

Funding

This work was supported by the European Community’s Seventh Framework Programme (FP7/2007–2013) (grant agreement number 223071, COURAGE in Europe); from the Spanish Ministry of Science and Innovation ACI-Promociona (grant number ACI2009–1010); the Instituto de Salud Carlos III-FIS (research grant numbers PS09/00295, PS09/01845, PI12/01490, PI13/00059, PI16/00218 and PI16/00173); and by the Instituto de Salud Carlos III Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). Projects PI12/01490 and PI13/00059 have been co-funded by the European Union European Regional Development Fund (ERDF) ‘A Way to Build Europe’.