Salivary cortisol in women with and without perimenstrual mood changes.

An increase in the activity of the hypothalamic-pituitary-adrenal axis (HPA axis) is frequently associated with major depression. During the premenstrual phase of their reproductive cycle some women experience depressive mood changes that are proposed to be of similar intensity to that experienced during periods of major depression. This study examined the secretion of cortisol, the end-product in the HPA axis, at different stages of the menstrual cycle in women with and without premenstrual depression. Women who experienced only mild physical and emotional changes in the premenstrual phase of their cycle had a significantly higher cortisol secretion on a premenstrual day (measured hourly) compared to a postmenstrual day. Those who were significantly more depressed premenstrually showed the opposite pattern of cortisol secretion with significantly lower levels on the premenstrual day compared with the postmenstrual day. Across the menstrual cycle, women who were significantly more depressed premenstrually also had lower evening cortisol levels in their premenstrual phase. The results of this study indicate that, unlike major depression where the underlying neurological changes are manifest as overactivity of the HPA axis, premenstrual depressive changes are associated with reduced HPA axis activity. Premenstrual depression may, therefore, be similar neurologically to seasonal affective disorder, which is associated with underactivity of the HPA axis.