Disorders of endocrine function are among the most common etiology of psychiatric illness.

The link between psychosis and hyperthyroidism is still poorly understood. We report an unusual presentation of hyperthyroidism as a psychotic state. Careful history, physical examination, and laboratory investigation, including thyroid function tests, should be part of the assessment of patients with any unexplained acute psychosis to detect this potentially curable disease. In this way, this article analyzes the psychiatric, physical and laboratory findings associated with hyperthyroidism and treatment.

To report a case of psychosis in a patient with endocrine disease.

Clinical records. Research on PubMed and Medscape using the Mesh Terms “hyperthyroidism”, “psychosis” and “thyroid and psychiatric manifestations”.

We present the case of a male patient, previously followed on our ambulatory psychiatric service for drug-induced psychosis. He was hospitalized due to psychotic symptoms, without substance abuse. Inpatient evaluation diagnosed hyperthyroidism. The patient did not present any somatic changes, except for psychosis. The patient was effectively treated with antipsychotics. He was referred to further evaluation and started antithyroid therapy.

Thyroid disease should be considered in the differential diagnosis of a broad spectrum of psychiatric symptoms. Psychosis is a rare complication of hyperthyroidism, ranging between 1–20%. The typical psychosis is reported to simulate manic-depressive psychosis. This association reinforces the need of a careful clinical evaluation in patients presenting with psychosis. Such psychiatric symptoms remit successfully with concomitant administration of antipsychotics and normalization of thyroid levels.

The authors have not supplied their declaration of competing interest.