Relationship of female sex hormones to mood states and disorders merits better research

Countless movies and TV shows make light of women's so-called "moodiness", often jokingly attributing it to their menstrual cycle or, conversely, to menopause.

In fact, mood disorders are a serious and pervasive health problem, and large-scale population studies have found women are 1.5 to 3 times more likely to suffer from major depressive disorder than are men.

In a newly published study, women's health experts from the University of Alberta argue there is an urgent need for carefully designed, gender-specific research to better understand the relationship of female sex hormones to mood states and disorders.

“The reasons for the gender disparity in rates of depression are not completely understood,” says Kathy Hegadoren, the Canada Research Chair in Stress Disorders in Women at the University of Alberta.

“But there is growing evidence that estrogens have powerful effects beyond their role in reproduction—that they play a critical role in mood disorders in women—and this opens new avenues for research into the underlying biological mechanisms and treatment of depression.”

Estrogen can be used to treat various mood disturbances in women—such as perimenopausal, postmenopausal and postpartum depression—but the results of these treatments can be difficult to interpret because researchers are only beginning to recognize the complex interactions among estrogens, serotonin and mood. “Right now, clinical use of sex-hormone therapies for the treatment of mood disorders is severely hampered by the inability to predict which women would respond well to such therapies,” explains study co-author and U of A nursing professor Gerri Lasiuk.

“Most animal studies looking at the causes of depression have been conducted with male animals and use chronic-stress models, which are assumed to be similar to depression.”

Hegadoren and Lasiuk's study recognizes that multiple factors may be at play in the development of mood disturbances, with individual, psychosocial and environmental factors interacting in complicated ways to create differential vulnerability in women and men. But they also point out that the link to sex hormones is hard to deny.

“Previous research has found that, before puberty, the rates of mood and anxiety disorders are similar in boys and girls. It's only after females begin menstrual function that a gender differential in mood disorders manifests itself. This, coupled with the observation that women appear to be especially vulnerable to mood disturbances during times of hormonal flux, certainly lends support to the claim that a relationship exists between sex hormones and mood,” says Hegadoren.

The study, co-authored by Hegadoren and Lasiuk, appears in the October 2007 issue of the journal Biological Research for Nursing .