Hashimoto’s thyroiditis denotes an autoimmune thyroid condition, characterized by T-cell infiltration and progressive destruction of thyroid tissue, leading to hypothyroidism, with diagnosis typically involving the detection of thyroid-specific antibodies and diffuse changes in the thyroid gland observed through ultrasonography. During destruction of thyroid gland cells, it is possible to experience increase in hormone levels temporarily resulting in transient hyperthyroidism (Hashitoxicosis or thyrotoxicosis). When the high level of hormones is managed by the body, the thyroid function starts to decline resulting in hypothyroidism, which causes depression and anxiety. It is suggested that people with thyroid autoimmunity are at increased risk of anxiety and mood-related disorders. Both conditions are caused by the same aberrancy present in the immuno-endocrinal center, which is difficult to correct. It is an established entity that thyroid hormones play an important role in mood and behavior, and cognition. Autoimmune thyroiditis, including Hashimoto’s thyroiditis, can lead to depression and anxiety disorders. It is thus important to enhance awareness among physicians about this connection to accelerate the diagnostic process. In patients with depression and anxiety disorders, a test for autoimmune thyroiditis should be performed, and in patients with autoimmune thyroiditis, a screening for psychiatric symptoms is necessary. Thus, patients presenting with anxiety or depression disorders should be treated and monitored by both an endocrinologist and a psychiatrist in liaison with each other so as to optimize their management. Moreover, an early recognition of an endocrine condition will help minimize psychiatric morbidity and hence improve health. This chapter addresses the prevalence, pathogenesis, clinical implications, and treatment of Hashimoto’s anxiety and depression. It also discusses the effect of thyroid hormones on the central nervous system, the link between autoimmune thyroiditis and psychiatric disorders, the association between Hashimoto’s thyroiditis and anxiety/depression disorders, as well as future perspectives.