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Can Thyroid Dysfunction Cause Depression and Anxiety?

Mental health is a growing concern in the United States. Reports state that annually an estimated 19 million adults in America suffer from depression and over 300 million worldwide. Some argue that the increasing number of societal stressors are to blame. Even though elevated stress is certainly a factor in the increasing rates of depression and other forms of mental dysfunction, there may be another significant yet often overlooked contributor in the form of thyroid disease.

What is the Thyroid?

The thyroid regulates a wide range of bodily functions through the production of various hormones. Three of the most influential being thyroxine (T4), triiodothyronine (T3), and reverse triiodothyronine (RT3). Each have unique attributes and play an important role in overall bodily function.

  • Thyroxine (T4) is the inactive or storage form of thyroid hormone. It is produced by the thyroid gland and stored until it is converted into either T3 or RT3. As such, a lack of T4 or poor conversion of T4 can result in hormonal imbalances and triggering system-wide disruption.
  • Triiodothyronine (T3) is the active form of thyroid hormone. T3 accelerates the activity of cells and tissues throughout the body. Without enough T3, the entire body slows down including various processes such as metabolism and neurological function. Conversely, too much T3 can result in over-acceleration of bodily function resulting in notable disruption.
  • Reveres triiodothyronine (RT3) regulates T3 by limiting its effect T3. In a sense, RT3 acts is a protective protocol against excess T3. However, overproduction of RT3 can trigger similar effects as a T3 deficiency even if T4 and T3 are maintained at the appropriate values.

Proper interaction and balance of these three hormones is essential for overall bodily function. Even minor irregularities in thyroid function or imbalances of thyroid hormone levels can cause serious dysfunction. Thyroid disease in the form of hypothyroidism, reduced thyroid function, and hyperthyroidism, hastened thyroid function, present a broad array of symptoms and can seriously disrupt mental health.

Learn more about the thyroid gland here.

The Connection Between the Thyroid and the Mind

Thyroid conditions are associated with greater occurrence of mental health issues such as depression and bipolar disorder. One review found that up to 60 percent of those with hyperthyroidism also experience clinical anxiety and nearly 69 percent of those with hypothyroidism also have depression. These associations make sense when considering the physical effects of thyroid dysfunction.

Hyperthyroidism increases thyroid hormone prevalence thereby hastening neurological activity. This prompts symptoms such as jitteriness, anxiety, and panic. In contrast, hypothyroidism reduces thyroid hormone values throughout the body including the central nervous system. This decline can prompt cause fatigue, weight gain, and lethargy, all of which are symptoms of clinical depression.

Defeating Depression by Treating the Thyroid

Doctors have found that treating an existing thyroid condition can dramatically improve mood, memory, cognition, and alleviate other factors of mental disruption. This is confirmed through various studies showing the efficacy of thyroid treatments in relieving depression and other mental health issues.

The Star*D Report, a large study evaluating the efficacy of multiple depression treatments, found that antidepressants often cause significant side effects and fail to improve the outlook of 66 percent of patients. Furthermore, data showed the rate of relapse in the first year for these medications was over 50 percent. In contrast, treatment with T3 therapies was found to be 50 percent more effective and presented fewer side effects than typical antidepressant treatments. This was consistent even in patients who did not respond well to antidepressants.

Another study found that T3 medications provide greater improvement of bipolar disorder and are more likely to facilitate complete remission than the average of 14 commonly prescribed bipolar medications.

These and other studies clearly show that effectively treating the thyroid can improve mental health. However, in order to get effective treatment, proper testing and assessment must be conducted.

Identifying and Testing for Thyroid and Mental Health Issues

Thyroid disease and depression are both woefully underdiagnosed and undertreated conditions. This is likely due to poor awareness and improper testing practices. To effectively improve mental wellness, proper thyroid testing and treatment must be made a priority

Accurate assessment of the thyroid requires thorough examination of various elements. Unfortunately, many doctors rely solely on TSH testing to evaluate thyroid function. Although valuable, TSH testing alone does not provide enough information to accurately gauge thyroid health and activity – learn more about the inadequacy of the TSH test here. The minimum tests needed to accurately gauge thyroid function are TSH, Free T3, Free T4, Reverse T3, and thyroid antibodies – get a FREE labslip here. It is important to note that patients with depression, anxiety, and other psychiatric issues tend to have irregular values of these thyroid hormones. In addition to TSH, T3, T4, and RT3, the following areas should be considered and assessed when gauging thyroid function:

  • Basal body temperature
  • Basal metabolic rate (BMR)
  • Free T3/Reverse T3 ratio
  • Reflex relaxation phase
  • SHBG (Sex Hormone Binding Globulin) levels
  • Signs and symptoms of thyroid conditions – get the full list of thyroid symptoms here.

Much like thyroid disease, depression and other mood disorders frequently go unnoticed or overlooked. In many cases a mood disorder or mental condition is identified and reported by the patient or those around them. Therefore, being familiar with the signs and symptoms of mental illness is essential. Neurological issues may promote symptoms such as:

  • Anger or rage
  • Changes in weight
  • Difficulty concentrating
  • Fatigue
  • Helplessness
  • Insomnia
  • Irritability
  • Lack of motivation
  • Loss of interest in previously enjoyable activities
  • Loss of sex drive or libido
  • Malaise or sadness
  • Muscle and joint pain
  • Poor appetite
  • Weakness

If you recognize these symptoms in yourself or others, seek out medical assistance.

Restoring Wellness Through Thyroid Care

Thyroid disease and mental dysfunction are connected to one another. Sadly, this relationship is not given the respect it deserves. Resolving mental health issues such as bipolar disorder, depression, and anxiety, often require proper thyroid assessment and treatment. Appreciating the influence of the thyroid over mental health and taking the appropriate steps to optimize its function through effective therapies can help bring about greater wellness and alleviate mental health issues.


1. Hage, Mirella P, and Sami T Azar. “The Link between Thyroid Function and Depression.” Journal of thyroid research vol. 2012 (2012): 590648.
2. Chakrabarti, Subho. “Thyroid functions and bipolar affective disorder.” Journal of thyroid research vol. 2011 (2011): 306367.
3. Harvard Health. “When depression starts in the neck.”
4. WebMD. “Depression, the Thyroid, and Hormones.”
5. Nierenberg AA, Fava M, Trivedi MH, et al. “A comparison of lithium and T3 augmentation following two failed medication treatments for depression: A STAR*D Report.” Am J Psychiatry 2006;163:1519-1530.
6. Rena Cooper-Kazaz, Bernard Lerer. “Efficacy and safety of triiodothyronine supplementation in patients with major depressive disorder treated with specific serotonin reuptake inhibitors.” International Journal of Neuropsychopharmacology, Volume 11, Issue 5, August 2008, Pages 685–699.
7. Tammas Kelly and Daniel Z. Lieberman. “The use of triiodothyronine as an augmentation agent in treatment-resistant bipolar II and bipolar disorder NOS.” Journal of Affective Disorders, Volume 116, Issue 3, August 2009, Pages 222-226.