Thyroid dysfunction and mental disorders

About 18% of adults in the United States have anxiety disorders, which include posttraumatic stress disorder, obsessive-compulsive disorder, and various phobias. About 7% of adults had at least one major depressive episode in the past year. Bipolar disorder affects about 2.5% of adults, and just over 1% of adults have schizophrenia. Serious mental-illness costs Americans more than $193 million in lost earnings annually. Thyroid dysfunction may be related to a variety of mental disorders. Depression is an example of a mental disorder that actually may be one of the first symptoms of thyroid dysfunction. Patients may be mislabeled as having a major mental disorder even though hypothyroidism or hyperthyroidism is causing their symptoms. When thyroid function is not normal, a variety of mental symptoms and conditions may develop. These include anxiety, bipolar disorder, depression, irritability, aggression, obsessive-compulsive disorder, panic attacks, phobia, and even schizophrenia. As many as 15% of patients treated for depression have elements of mild or overt hypothyroidism. Conditions commonly linked to mental disorders include cretinism, myxedema, and Graves’ disease with stress.