Medline Plus states that more than 20 million Americans suffer from some form of depression. Besides the unfortunate and less favorable events in life that can lead people to becoming depressed, hormones, too, play an important part.
The relationship between hormones and depression, however, proves complex. Without diving deep into the workings of biochemistry and the human body, a few particular relationships exist in which hormones are significant to the onset of depression.
Female Reproductive Hormones
Women have significantly higher rates of depression than men. Although the link is not clear, hormones influence depression throughout a woman's entire lifetime. Girls who begin puberty early are more likely than girls who mature later to experience depression as adolescents. Premenopausal women also prove prone to depression: 22 percent of women between the ages of 20 and 45 report symptoms of major depression; 3 to 8 percent experience premenstrual dysphoric disorder, or severe depression before a period, says Health Central. And for many women entering or going through menopause, depression proves common.
In addition to what has long been known about postpartum depression, recent data has surfaced about the prevalence of depression during pregnancy. Dr. Catherine Roca, chief of Women's Programs with the National Institute of Mental Health, states that prenatal depression occurs more frequently than once thought and serves as a strong precursor for developing postpartum depression.
Thyroid Function
The role that thyroid function plays remains unclear; however, there is a direct relationship between both an overactive and underactive thyroid and depression. The European Journal of Endocrinology reports that case studies have documented depression as a symptom of thyroid diseases, and certain thyroid hormones have proven successful for treating major depression.
Cortisol
Cortisol is a hormone produced in response to stress, anxiety, anger or fear. Most people's cortisol levels peak in the morning and decrease throughout the day. Although for sufferers of major depression, the amount of cortisol in the bloodstream peaks earlier in the morning, remaining at levels higher than normal in the afternoon and evening. It's still unknown if these imbalances cause depression or if the illness gives rise to the imbalances, but the relationship exists, says HealthyPlace.
