RESUMO
Cognitive impairment among patients with hypothyroidism is a well known condition, but its pathophysiology is not fully understood. Thyroid hormones may influence several processes in the brain, including cerebral perfusion, cerebral metabolism and neurotransmitter activity and could partially explain the neuropsychiatric manifestations of hypothyroidism. Acute psychosis is rare as a manifestation of hypothyroidism, but is potentially reversible. We report a 37 years old female without a previous history of psychiatric illness, presenting with an acute psychosis that required hospital admission. Her serum TSH was 122.2 uUI/mL (normal 0.3-4.2 uUI/mL), her total T4 was 1.1 ug/dL (normal 4.6-12 ug/dL), her free T4 was 0.1 ng/dL (VN 0.9-1.7 ng/dL), her total T3 was 30.5 ng/dlL (normal 84-201 ng/dL), and her antiTPO antibodies were 5464 UI/mL (normal < 12 UI/mL). Thyroid substitution was started with an important remission of psychotic symptoms. One month later, anti-psychotic medication was discontinued.