Stress is Worse in Women and Can Predict Post-Partum Depression
According to a recent government report, women are twice as likely to suffer from major depression and three times more likely to attempt suicide compared to men. Women also experience anxiety disorders two to three times more often than men. These gender disparities have been attributed to fluctuations in female hormones, which can occur on a monthly basis in women with premenstrual syndrome who experience increased irritability and mood swings. PMS can cause such violent behaviors that it has been successfully used as a defense for criminal acts ranging from shoplifting to murder. Menopausal depression due to a drop in estrogen is not uncommon and improves in most patients with hormone replacement therapy. Estrogen levels soar 50 times higher than normal during the last trimester of pregnancy and then plummet in the 48 hours after birth. Progesterone increases 10-fold and similarly falls 90-95 percent and there may be significant changes in prolactin, oxytocin, thyroid and other hormones following delivery. Almost 80 percent of new mothers may experience temporary “baby blues” with mild symptoms of sadness and mood swings that disappear spontaneously after a few days. One in five suffers from postpartum depression, which is characterized by crying, difficulty sleeping, and a decreased ability to function normally or provide adequate infant care. Postpartum psychosis is much less common (1 in one thousand births) but also much more serious. Strange symptoms usually start to surface within a few weeks after delivery, such as; feelings of being ordered by God or a some higher power to do something harmful to oneself or the baby; seeing or hearing things that others do not; periodic feelings of intense confusion or agitation or fluctuating between extreme highs and lows of energy.
What triggers postpartum mental illness is not clear but risk factors include a past history of depression, especially after a prior pregnancy, and stressful events during the past year such as job loss, illness, marital conflict, and a pregnancy that is unwanted, unplanned or associated with complications. The association between stress and depression is well established since depressed patients frequently have elevated levels of cortisol due to overactivity of the hypothalamic-pituitary-adrenal (HPA) axis. This starts with stimulation of corticotropin releasing hormone (CRH) in the hypothalamus, which triggers pituitary production of ACTH that stimulates the adrenal cortex to secrete cortisol.
It is not generally appreciated that during pregnancy, the placenta also produces CRH, which is identical to hypothalamic CRH. The only difference is that while increased cortisol hypothalamic CRH, it stimulates the production of CRH in the placenta. As a result, production of placental CRH steadily increases during pregnancy and eventually reaches levels usually seen only during conditions of severe stress in nonpregnant controls. Researchers believe that the sudden disappearance of the placenta following delivery results in a sharp drop in CRH that can lead to postpartum depression by disrupting normal HPA axis regulation. Since this sudden change would be greatest in those with very high levels of CRH, it seemed likely that placental CRH measurements might be useful in predicting the likelihood of developing postpartum depression. The results were impressive in a recent study of 100 pregnant women, 16 of which developed postpartum depression. Researchers could accurately predict this in three out of four by blood tests alone and did even better when these results were combined with measurements of depression during pregnancy. This could be an important breakthrough if confirmed in larger studies now underway, since it would allow physicians to implement prompt preventive and treatment interventions that have been shown to be much more effective when implemented as early as possible.
Yim IS, Glynn LM et al. Risk of Postpartum Depressive Symptoms With Elevated Corticotropin-Releasing Hormone in Human Pregnancy Arch Gen Psychiatry. 2009;66(2):162-169.
Rosch PJ. Stress – Is It Worse For Women Or Men? Health and Stress: The Newsletter of The American Institute of Stress. No. 7, July 2009