Table 2.

Estradiol as a potential target to treat insomnia in postmenopausal women with schizophrenia.

Animal Studies
Estrogens are neuroprotective and show a positive influence on behavioral symptoms in animal models of schizophrenia (e.g., prepulse inhibition in rats).	Estrogens may influence sleep regulation.
Human Studies
Estrogens may vary according to the phases of the menstrual cycle. High estrogen levels are associated with improvements in psychotic symptoms.	Estrogens and progesterone differ according to the phases of the menstrual cycle in premenopausal women and are found to influence sleep.
Sleep architecture worsens during the menopausal transition. Insomnia is frequent at menopause.	Loss of estrogens is associated with sleep disturbances at menopause. In schizophrenic women, this association may be stronger.