Depression, the Thyroid, and Hormones
What Causes Thyroid Disease? continued...
Hypothyroidism can also be a side effect of certain drugs, such as lithium and amiodarone, and by iodine deficiency. The thyroid gland uses iodine to make hormones. Iodine deficiency is not a problem in the United States because of the use of iodized salt. However, iodine deficiency is a problem worldwide.
Hyperthyroidism may be caused by:
- Graves' disease, an enlarged thyroid gland (also called diffuse toxic goiter)
- nodules that may form in the thyroid and may cause it to be overactive
- thyroiditis, an inflammation of the thyroid gland that can cause the release of stored hormones (If thyroiditis causes all the hormones to be released, hypothyroidism can follow.)
- excessive iodine, which might be found in certain drugs and some cough syrups
How Is Thyroid Disease Treated?
The goal of treatment for any thyroid disorder is to restore normal blood levels of thyroid hormone. Hypothyroidism is treated with the drug levothyroxine or triiodothyronine.
- Brand names for levothyroxine are Synthroid, Unithroid, Levoxyl, and Levothroid. Levothyroxine is a synthetic hormone that replaces missing thyroid hormone in the body.
- The brand name for triiodothyronine is Cytomel.
- Sometimes the combination of levothyroxine and triiodothyronine is prescribed as two separate pills or, more rarely, as a single pill called liotrix (brand name Thyrolar).
Hyperthyroidism is generally more difficult to treat. That's because it requires the normalization of thyroid hormone production. Treatment might involve drug therapy to block hormone output. Or it might involve radioactive iodine treatment to disable the thyroid. Surgery may be used to remove some or all of the thyroid gland.
Treatment with radioactive iodine, the most common therapy, often causes hypothyroidism. So levothyroxine is used following treatment in order to normalize hormone levels.
What Other Hormone-Related Conditions Are Associated With Depression?
First, as noted earlier, women are more likely than men to develop thyroid conditions. Women are also more likely than men to be diagnosed with depression. Because of biology, women are more vulnerable to hormone-induced depression.
The process of menstruation involves fluctuations in the levels of estrogen and other hormones. Some women experience depression-related symptoms such as sadness, irritability, and fatigue prior to menstruation. These symptoms are part of the premenstrual syndrome, or PMS. A more severe case of emotional problems related to menstruation is known as premenstrual dysphoric disorder (PMDD).
When pregnant, women are subject to physical and emotional changes caused in part by changes in hormones. After pregnancy, women experience a huge shift in hormone levels. This shift is a likely cause of the "baby blues," a mild type of depression that immediately follows childbirth in up to about 80% of women and generally resolves quickly. A more severe form of depression -- post-partum depression -- could also result less often (in about 10-20% of new mothers).