Role of thyroid hormone therapy in depressive disorders

• Published in: Journal of endocrinological investigation Vol. 44; no. 11; pp. 2341 - 2347
• Main Authors: Bauer, M., Whybrow, P. C.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-11-2021; Springer Nature B.V
• Subjects: Antidepressants; Antidepressive Agents - pharmacology; Bipolar disorder; Bipolar Disorder - drug therapy; Bipolar Disorder - metabolism; Depressive Disorder - drug therapy; Depressive Disorder - metabolism; Drug Interactions; Emotional disorders; Endocrine therapy; Endocrinology; Hormones; Humans; Internal Medicine; Medicine; Medicine & Public Health; Mental depression; Mental disorders; Metabolic Diseases; Mood; Mood disorders; Neuroimaging; Patients; Placebos; Positron emission tomography; Prophylaxis; Short Review; Thyroid Diseases - metabolism; Thyroid Diseases - psychology; Thyroid gland; Thyroid hormones; Thyroid Hormones - metabolism; Thyroid Hormones - pharmacology; Thyroxine; Thyroxine - pharmacology; Triiodothyronine; Levothyroxine; Bipolar disorder; Triiodothyronine; Major depression; Thyroid hormone treatment
• ISSN: 1720-8386; 0391-4097; 1720-8386
• DOI: 10.1007/s40618-021-01600-w

Purpose
The close association among thyroid metabolism, mood disorders and behavior has long been known. The old and modern uses of thyroid hormones to modulate the expression of depression and bipolar disorder and to improve clinical outcome when used in conjunction with psychotropic medications.
Methods
A literature search was performed to identify studies investigating the effects of thyroid hormone treatment in patient s with mood disorders.
Results
The successful modification of mood disorders with thyroid hormone underscores the association between endocrine and cerebral systems in these disorders. Thyroid hormones have a profound influence on behavior and appear to be capable of modulating the phenotypic expression of major mood disorders. In fact, there is evidence that triiodothyronine (LT3) may accelerate the antidepressant response to antidepressants, and studies suggest that LT3 also may augment the response to antidepressants in refractory depression. Add-on treatment with supraphysiologic doses of levothyroxine (LT4) has shown efficacy in open-label and in placebo-controlled studies, including in rapid cycling and prophylaxis-resistant bipolar disorder, and with acute refractory uni- or bipolar depression. Functional brain-imaging studies (PET) demonstrated that administration of supraphysiologic LT4 improves depressive symptoms in patients with bipolar depression by modulating cerebral activity in the anterior limbic network.
Conclusion
The add-on administration of supraphysiologic doses of LT4 is a promising strategy in patients with refractory bipolar and depressive mood disorders.