Premenstrual depression, postnatal depression and climacteric depression are related to changes in ovarian hormone levels and can be effectively treated by hormones. It is unfortunate that psychiatrists have not accepted this form of treatment and this paper is an attempt to simplify this treatment, which should include transdermal estrogens, possibly testosterone and, if the woman has a uterus, also progestogen. A balance is often necessary between these three hormones. Transdermal estrogens in the appropriate dose will suppress ovulation and suppress the cyclical hormonal changes that produce premenstrual depression. Estrogens also have a mood-enhancing effect in postnatal depression and the depression in the transitional phase of the menopause. It is possible to add transdermal testosterone which will improve mood, energy and libido. The problem is the progestogen as these women are often progestogen-intolerant. Progestogen should be used in the lowest dose and for the shortest duration necessary to prevent endometrial hyperplasia or the return of premenstrual syndrome-type symptoms if the women are progestogen-intolerant. The use of estrogens for depression in these women does not exclude the use of antidepressants. Hormone-responsive depression cannot be diagnosed by measuring hormone levels but can only be diagnosed by a careful history relating depression to the menstrual cycle, pregnancies and the perimenopausal years. These appropriate questions should prevent the endocrine condition of premenstrual depression being misdiagnosed as bipolar disorder and the woman given inappropriate treatment.