Periodic psychoses, belonging to the group of atypical psychoses, have the following characteristics in common, i. e. acute onset and tendency toward relapse; emotional disturbances, psychomotor disorders and alterations of consciousness as basic mental symptoms; alternations between the two extremes of emotional and psychomotor disorders, such as manic-depressive, anguished-ecstatic and excited-stuporous states. In some types of periodic psychoses which periodically recur in association with menstruation, several cases in which female hormone therapy was remarkably effective have been reported. In this review, the author considers conceivable action mechanisms of female hormone therapy in periodic psychoses based on the literature. A summary follows.
 Psychotic phases accompanying anovulatory cycles are considered to be caused by the functional vulnerability in high integrate centers closely connected with the hypothalamus. In such conditions, hypoestrogenism following defective folliculogenesis disrupts LH pulsatility and inhibits estrogen-induced LH surge. A conceivable action mechanism of female hormone therapy in psychotic phases accompanying anovulatory cycles, i.e. clomiphene citrate, combined estrogen plus progestin in the latter half of the menstrual cycle, involves bringing the periodic activity of hypothalamic function throughout the menstrual cycle close to a physiologically normal pattern. In contrast, psychotic phases accompanying ovulatory cycles are considered to be based on an established pathological autonomy in high integrate centers, rather than vulnerability. In addition to pathological autonomy, increased estrogenic action in the central nervous system has also been considered as one of the common pathologies of psychotic phases accompanying ovulatory cycles. Therefore, female hormone preparations having both anti-gonadotropic and anti-estrogenic activities are effective in the treatment of psychotic phases accompanying ovulatory cycles. In such cases, inhibition of ovulation is helpful in some patients but not in others.
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