The Critical Period Hypothesis: Can It Explain Discrepancies in the Oestrogen-Cognition Literature?
Article first published online: 28 NOV 2006
Journal of Neuroendocrinology
Volume 19, Issue 2, pages 77–81, February 2007
How to Cite
Sherwin, B. B. (2007), The Critical Period Hypothesis: Can It Explain Discrepancies in the Oestrogen-Cognition Literature?. Journal of Neuroendocrinology, 19: 77–81. doi: 10.1111/j.1365-2826.2006.01508.x
- Issue published online: 28 NOV 2006
- Article first published online: 28 NOV 2006
- Accepted 17 October 2006
- critical period
Although there is compelling evidence from small randomised controlled trials and cross-sectional studies indicating that oestrogen helps to protect against cognitive ageing in women, the findings of the large, Women's Health Initiative Memory Study failed to support the earlier findings. The attempt to resolve these discrepancies led to the formulation of the Critical Period Hypothesis which holds that oestrogen has maximal protective benefits on cognition in women when it is initiated closely in time to a natural or surgical menopause but not when treatment is begun decades after the menopause. This article reviews the evidence from basic neuroendocrinology, from animal behavioural studies and from human studies that supports the critical period hypothesis. In view of the promise of this hypothesis and its considerable clinical implications, a direct test of its validity is warranted.