The relationship between thyroid function and psychological wellbeing was established well over two hundred years ago (Hage & Azar, 2011). Sciences of the body and mind recognize that fluctuations in thyroid functioning can significantly affect emotions and thoughts. Both an excess of thyroid hormone (hyperthyroidism) and a depletion of thyroid hormone (hypothyroidism) can cause mood disturbances, including depression. One positive note is that depression caused by thyroid malfunction may be easily treated with the right corrective medication. However, knowing what came first, the depression or the thyroid changes is a case of the chicken and the egg, and is not always that simple (Hage & Azar, 2011).
Hypothyroidism is more common among women than in men, and as many as one in five women will develop hypothyroidism by the age of 60. However, the relationship between the thyroid gland and mood disorders is not that clear. Most patients with depression do not exhibit thyroid changes, and many patients with hypothyroidism, do not exhibit typical diagnostic criteria for depression (APA, 2013; Harvard Medical School, 2011).
Both depression and hypothyroidism can share some symptoms including: weight gain, feelings of confusion and a depressed mood. Other symptoms of hypothyroidism include temperature dysregulation, hair loss, constipation and tachycardia. Many stressful life events can have a cumulative impact contributing to a depressed mood in addition to thyroid dysregulation. Speaking with a health professional as well as a mental health professional can help to alleviate symptoms.
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.
Hage, M. P., & Azar, S. T. (2011). The link between thyroid function and depression. Journal of thyroid research, 2012.
Harvard Medical School. (2011, July). When depression starts in the neck. Harvard Mental Health Letter, retrieved from: http://www.health.harvard.edu/newsletters/Harvard_Mental_Health_Letter/2011/July/when-depression-starts-in-the-neck