1998 Curt P. Richter Award - The effect of hormone replacement therapy on cognitive function in elderly women

Although evidence seems to indicate favorable effects of hormone replacemen t therapy (HRT) on cognitive functions and mood in elderly healthy and deme nted women, some questions remain. For instance, the nature of the long ter m effect of HRT, e.g. in preventing cognitive decline is still unclear. In this respect the addition of progestagens in combined HRT has been mentione d to oppose some of the beneficial effects of estrogens. The present paper aims to illuminate these questions and presents two studies. Tn the first s tudy, the long term effects of combined HRT in healthy postmenopausal women was investigated using a parallel groups (HRT-users vs. controls) design. HRT subjects were always tested during the estrogen-progestagen phase. Resu lts indicated that after 6 and 12 months, women in the HRT-treatment group had higher scores on several indicators of the subjective feeling of well b eing (sleep, physical and psychological complaints) than matched controls, although at baseline both groups were not severely impaired. Effects of HRT on memory functions were seen when HRT treated subjects were compared with their own baseline functioning, but not when compared with controls. Hence , the addition of progestagen did not oppose the effects of estrogens on su bjective feelings of well being or on memory. Our second (case-control) stu dy involved women of middle-age who were unaware of the purpose of the expe riment. mo positive effects of HRT use on subjective scales of well being o r on memory were found. However, women with HRT were faster on basic sensor imotor speed tasks as compared with controls. It should be kept in mind tha t double blind testing in an experimental study is difficult due to withdra wal bleeding and the reduction of flushes. Expectancy effects may hav confo unded the results of the first study. However, our findings indicate that t he use of a particular design and type of memory test can explain the contr oversial results of studies into the effect of HRT on cognitive function. F urthermore, it was concluded that HRT has a global activating, instead of s pecific direct effect on cognitive functions. (C) 1998 Elsevier Science Ltd . All rights reserved.