The thyroid, a small gland located in your neck, secretes thyroid hormones that control your energy level and other bodily functions. So it's no surprise that the symptoms of an out-of-whack thyroid glad can mimic those of mental illness.

The most common form of thyroid disorder is hypothyroidism. Hypothyroidism, in which a person has low levels of a thyroid hormone, causes the thyroid to function sluggishly. It's much more prevalent in women than men. In fact, according to the University of Maryland Medical Center, up to 6 percent of all women over 60 have hypothyroidism, with as many as 20 percent more at risk of developing it. But premenopausal women suffer from it, too, with pregnancy a particular risk factor.

Studies have demonstrated that a significant percentage of depression sufferers also exhibit signs of hypothyroidism, although in many cases the hypothyroidism symptoms are not obvious and the link is discovered only when levels of thyroid hormone are tested. Since the symptoms of hypothyroidism are similar to those of depression--including mental slowdown, loss of energy and interest in formerly enjoyable activities, confusion, memory problems, weight gain, and feelings of despair--it's not always clear what is causing the symptoms. The good news is that many depressed patients with hypothyroidism find relief by taking synthetic thyroid hormones. In fact, antidepressants may not even be necessary in these cases.

Much less common than hypothyroidism is hyperthyroidism, in which the thyroid overproduces thyroid hormone. This can result in feelings of anxiety, tension, impatience, irritability, and weight loss. Treatments include anti-thyroid drugs or radioactive iodine treatment, which often does the job in a single dose.

If you're feeling tired and hopeless, or nervous and panicked, it's important to talk to your doctor before going on antidepressant or antianxiety drugs--so you can find out if your thyroid is the true cause of your problem.


Sources: Thyroid Foundation of Canada,, University of Maryland Medical Center,