Stress, glucocorticoids, and memory: a meta-analytic review.

Although a strong psychoneuroendocrine linkage exists between stress, glucocorticoids and memory, the relationship is not always straightforward. Eighty-eight effect sizes and 1642 participants from 28 studies were meta-analyzed for the effects of stress on memory performance and glucocorticoid activation. Analyses showed that stress was associated with glucocorticoid activation and declarative memory decline. In animal studies, predator stress affected memory performance more than physical stress. In human studies, males showed higher cortisol levels than females in response to stress. Further, the correlation between cortisol levels and memory deficits was stronger in studies using laboratory stressors than those examining long term effects of chronic exposure to rising basal levels of glucocorticoids and chronic life stressors. It was concluded that, although the relationship between stress, glucocorticoids, and memory loss was empirically supported, there were other factors, such as stress condition and gender, as well as individual differences within groups, that influenced the association between these variables, and warrant further examination.