Sex hormones, mood, mental state and memory

Oestrogen and testosterone, the main sex steroid hormones, have long been k nown to affect behaviour. They also affect mood, mental state and cognition . Recent experimental findings suggest that these effects of sex hormones m ay be mediated by serotonin, an important neurotransmitter, dysfunction of which has been implicated in mood disorders and schizophrenia. The oestroge n-serotonin link has relevance for the rational design of novel antioestrog ens and of hormone replacement therapy.