Arch Womens Ment Health (2002) 5: 83–86 DOI 10.1007/s00737-002-0142-6 Short communication Fertility and number of children in patients with Alzheimer’s disease U. Ptok, K. Barkow, and R. Heun Department of Psychiatry, University of Bonn, Bonn, Germany Accepted July 23, 2002; Published online October 7, 2002 © Springer-Verlag 2002 remain controversial. Postmenopausal oestrogen re- placement in healthy women seems to protect against Alzheimer’s disease (AD), even though oestrogen is apparently not effective for the treatment of the disease once the disease has developed (for the effects of HRT on cognition in elderly women see a meta-analysis by Hogervorst et al., 2000). The effects of natural exposure to oestrogen in cognitive disorders have rarely been studied. Some studies that have measured endogenous concentra- tions of estradiol in healthy postmenopausal women have yielded controversial results regarding cog- nitive performance depending on hormone concen- trations. Some studies have suggested a positive association of estradiol and cognitive performance (Yaffe et al., 2000; Barret-Connor and Kritz- Silverstein, 1999) whereas others have not or have even shown an inverse relation of hormone concen- trations and cognition (Yaffe et al., 1998; Carlson and Sherwin, 1998; Polo-Kantola et al., 1998; Barret- Connor et al., 1999). To our knowledge there is no literature on endogenous hormone concentrations and the later development of dementia. There is evidence that parity resets ovarian func- tion in the non-gravid state, resulting in permanently lower oestrogen concentrations in parous women compared with nulliparous women (Hankinson et al., 1995; Bernstein et al., 1985; Trichopoulos et al., 1980). Assuming that nulliparous women have a higher exposure to natural oestrogen, it could be hypothesised that this might have an effect on their cognitive performance. Lyketsos and McLay (2000) Summary Oestrogen therapy has been suggested to have protective effects against Alzheimer’s disease. The effects of natural exposure to oestrogen in cognitive disorders have rarely been studied. Assuming that nulliparous women have a higher exposure to natural oestrogen, it could be hypothesised that these women might have a lower risk of Alzheimer’s disease than women who have had children. The fertility and number of children in 106 women with a diagnosis of Alzheimer’s disease was examined and compared with that of 189 female subjects from two control groups with subjects without dementia. As additional control, the same comparisons were carried out for 40 male patients with Alzheimer’s disease and 105 male control subjects. In female subjects, having had children was found to be associated with a diagnosis of Alzheimer’s disease. This was not the case in male subjects. The number of children did not seem to affect the risk of Alzheimer’s disease, neither in female nor in male subjects. Natural exposure to oestrogen seems to reduce the risk of Alzheimer’s disease in women. Keywords: Alzheimer; reproductive history; endogenous oestrogen; fertility. Introduction Sex differences in the prevalence of Alzheimer’s dis- ease require the research of gender specific aspects of the epidemiology, neurobiology, and treatment options of this frequent and devastating disorder. In recent years, epidemiological studies as well as clinical trials have studied the effects of hormone replacement therapy (HRT) on cognition and cogni- tive disorders (Hogervorst et al., 2000). Oestrogens have been shown to have neuroprotective effects in vitro and in animal models (Garcia-Segura et al., 2001; Chowen et al., 2000), but the results of ex- perimental and epidemiological studies in humans