Psychosocial stress associated with memory performance in older South African adults

ABSTRACT

Older adults with past or current chronic stress exposure perform poorly on memory assessments and are at higher risk for Alzheimer’s disease (AD). In low- or middle-income countries, many older adults are, or have been, exposed to stress-provoking events. Few published studies examine such populations, however, and few take multiple measures of stress. In a sample of South African older adults with mild-to-moderate AD (n = 65) and healthy controls (n = 69), we assessed relations between stress (psychosocial and physiological), memory performance, and patient status. Participants, all aged > 60, were administered the Perceived Stress Scale (a questionnaire assessing subjective psychosocial stress) and the Cambridge Cognitive Examination-Revised (CAMCOG-R; a test battery measuring performance across several cognitive domains). We measured their salivary cortisol concentrations as a proxy for physiological stress. Patients reported significantly higher levels of psychosocial stress than controls, p = .008. Logistic regression showed that psychosocial stress, but not cortisol, predicted AD patient status. CAMCOG-R Memory subscale scores were significantly associated with psychosocial stress, r = −.18, p = .040, but not with cortisol levels. These findings are the first on the topic to emerge from a low-or middle-income country. We replicated findings from previous studies conducted in high-income countries, with data supporting predictions derived from the glucocorticoid cascade/neurotoxicity hypothesis. The results suggest that clinical interventions focused on increasing resilience of older adults to effects of chronic stress may help protect against declining memory performance and reduce the risk for AD.

KEYWORDS:

• Aging
• Alzheimer’s disease
• cortisol
• memory
• stress

Acknowledgments

The authors thank the participants for their involvement in this research, the research team from the Clinical Neurosciences Research Unit at Groote Schuur Hospital for assistance with data collection, and Dr. Celeste de Jager for her valuable input and critical review of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.

Additional information

Funding

This work was supported by the South African Research Chairs Initiative under grant number 443293, awarded by the National Research Foundation of South Africa.