Why are women twice as likely as men to develop Alzheimer’s disease? I discuss some important differences in the way women's brains age and how this increases their risk of developing Alzheimer’s disease. It’s not that a female brain is fundamentally different to a male brain. But there are some really important differences in the way a female brain responds to hormonal changes at different stages of life that drives brain ageing in women, significantly increasing their risk of developing Alzheimer’s.