The objective of the research project is to estimate the effects of premenopausal prophylactic bilateral oophorectomy on psychological symptoms (depression, anxiety), health related quality of life, and sex life. The study is a rigorous systematic review of existing scientific literature, utilizing up-to-date methodology to eliminate bias. Use of hormonal replacement therapy is taken into account as a major modulating factor of the effects. The unbiased retrieval of the research reports is guaranteed by the use of comprehensive prospective registers, "reverse searching", searching "grey literature", handsearching and contacts with research institutions. The validity of the studies will be assessed by use of pre-existing, design-specific quality instruments. Fixed effect meta-analyses, including homogeneity tests and sensitivity analyses, will be used to quantitatively combine estimates on comparable outcome variables. The report will be prepared with special emphasis on clinical relevance.