The "blues" is considered the mildest form of the postpartum mood disturbances, and has been reported at a prevalence of 25-85 % depending on the diagnostic criteria used. The symptoms of this syndrome typically begin within the first few days following childbirth, peak on the fifth day and resolve shortly thereafter. The mood disturbance characterizing postpartum "blues" is considered insufficient in and of itself to cause serious impairment of a woman's functioning. In some women, however, the disturbance may persist beyond the initial puerperium, leading to more serious disorder.