Euthyroid depression: the role of thyroid hormone.

Thyroid dysfunction and psychiatric disorders share a bidirectional relation. Thyroid hormones have been found to affect the central nervous system both structurally and functionally. Conventional antidepressant drug therapy is characterized by a delayed and at times suboptimal response. Various strategies have been devised in order to circumvent this limitation. L- Thyroxine has been used as both acceleration therapy and augmentation therapy as adjuvant therapy with antidepressants. The hormone has also been used as monotherapy, both in prevention and management of depression. The potential use of thyroid hormone as an adjunct therapy in management of euthyroid depression and relevant patents has been discussed.