Hashimoto encephalopathy (HE) is an uncommon syndrome associated with Hashimoto thyroiditis. The relationship between these entities is unclear. Even being rare, it appears to be underrecognized.

Report a case of an atypical presentation of psychosis in a patient with elevated serum levels of antithyroid antibodies and review the literature about similar situations.

Access clinical process, research PubMed, using the mesh terms “Hashimoto encephalopathy” and “psychosis”.

A 21-year-old Portuguese female was conducted by authorities to our emergency department after she called for help and was spotted walking barefoot on the streets. Throughout clinical course she presented persecutory ideas, thought blocks, auditory hallucinations, soliloquies, perplexity, total insomnia, bizarre behaviors like coprophagia, trichotillomania and self-injured burns. After some tests, it was found that the patient had high serum levels of antithyroid peroxidase antibody (TPO) and antithyroglobulin antibody (TGO) and reduced folic acid, without other changes. Trials with corticosteroids showed clinical improvement for short periods, as with antipsychotics. No consistent remission was achieved with either approaches.

HE is an uncommon syndrome presenting with high titers of antithyroid antibodies that may preconize an acute state of atypical psychosis. Usually, it responds to corticosteroids and so, has a generally good prognosis when treated accordingly. Evidence suggests that HE is an autoimmune disorder instead of thyroid disease.

The author has not supplied his/her declaration of competing interest.