Autoimmune Schizophrenia? Psychiatric Manifestations of Hashimoto's Encephalitis

Hashimoto's encephalitis (HE), also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), can be a debilitating manifestation of an autoimmune reaction against the thyroid that is often under-diagnosed primarily due to a lack of definitive diagnostic criteria. This is a case of a 52-year-old woman who has been diagnosed with HE after presenting with recurrent and severe psychosis in conjunction with paranoia and a thyroidopathy. Her symptoms are chronic, having first been documented as presenting 15 years prior and showing progressive exacerbation in both frequency and severity. The patient's paranoia often manifested as delusions involving family members or close friends and consequently introduced an opportunity for harm to herself and others. She showed great conviction with self-diagnoses that were proven incorrect, resulting in occasional noncompliance. Between episodes, the patient did not show evidence of symptoms. This patient struggled with several incorrect diagnoses and treatments for several years before the correct diagnosis of HE was made and displayed extreme improvement upon corticosteroid administration. This case illustrates the importance of increasing awareness of HE as well as including HE in a differential diagnosis when any patient presents with psychosis and concurrent thyroidopathy. Hashimoto's encephalitis follows putative characteristics of autoimmune diseases, exhibiting a higher incidence in women as compared to men, presenting with increased titers of autoantibodies, and showing dramatic amelioration when treated with corticosteroids.