Antithyroid medications and psychosis

Introduction: Antithyroid drugs (ATDs) are used in the treatment of hyperthyroidism. Very rarely ATDs were reported to trigger acute psychosis in patients with no history of psychiatric disturbances. Our aim is to review the literature on psychosis as a side effect of ATD and to give a personal opinion on this issue. Areas covered: The cases of acute psychosis elicited by ATD are few and most were reported many years ago, before radioimmunoassay for thyroid-stimulating hormone (TSH) and thyroid hormones was introduced. Most of those cases lack a description of serum thyroid hormone profile before, during and after the appearance of the psychiatric disorder; hence, an abrupt shift from hyperthyroidism to euthyroidism or hypothyroidism cannot be excluded. In addition, patients underwent specific psychiatric therapy, so that it is difficult to attribute the disappearance of the mental disorders to the withdrawal of ATD per se. Expert opinion: Patients who develop mental disorders while under ATD should be followed by an accurate evaluation of TSH, free triiodothyronine (FT3), and free thyroxine (FT4) levels throughout the course of the psychiatric disease. The use of new imaging techniques could be helpful in ruling out the encephalopathy associated with autoimmune thyroid diseases and other cerebral pathologies that might be possible causes of these mental disorders