Acute psychiatric admission related to the menstrual cycle.

A study of menstrual cycle phase on the day of acute admission to a psychiatric hospital for 121 women aged 20-39 showed an unequal distribution of admissions. More admissions than expected took place in the menstrual period, and correspondingly fewer intermenstrually. The difference was significant, and points to a certain degree of cyclicity in female psychiatric disturbance. This cyclicity was not significantly influenced by age, diagnosis, oral contraceptives or tendency for premenstrual symptoms. In the age group 20-39 one and a half times as many men as women are admitted to Danish psychiatric departments. Thus, in view of a common baseline, the most conspicuous feature is, that remarkably few women were admitted intermenstrually.