We describe herein an unusual case of subacute thyroiditis presenting as acute psychosis. An 18-year-old male presented at the emergency department due to abnormal behavior, psychomotor agitation, sexual hyperactivity, and a paranoid mental state. Laboratory findings included an erythrocyte sedimentation rate of 36 mm/hr (normal range, 0 to 9), free T4 of 100.0 pmol/L (normal range, 11.5 to 22.7), and thyroid stimulating hormone of 0.018 mU/L (normal range, 0.35 to 5.5). A technetium-99m pertechnetate scan revealed homogeneously reduced activity in the thyroid gland. These results were compatible with subacute thyroiditis, and symptomatic conservative management was initiated. The patient's behavioral abnormalities and painful neck swelling gradually resolved and his thyroid function steadily recovered. Although a primary psychotic disorder should be strongly considered in the differential diagnosis, patients with an abrupt and unusual onset of psychotic symptoms should be screened for thyroid abnormalities. Furthermore, transient thyroiditis should be considered a possible underlying etiology, along with primary hyperthyroidism.
Acute Disease ; Adolescent ; Antipsychotic Agents/therapeutic use ; Humans ; Male ; Psychotic Disorders/diagnosis/drug therapy/*etiology ; Thyroiditis, Subacute/*complications/diagnosis/therapy ; Treatment Outcome

Methylenetetrahydrofolate reductase (MTHFR) deficiency is a rare autosomal recessive disorder. It is known that MTHFR deficiency may result in hyperhomocysteinemia, but MTHFR deficiency-induced schizophrenia has been rarely reported. Here we present the clinical course, biochemical and genetic characteristics of schizophrenia resulted from MTHFR deficiency in a school-age boy. He was 13 years old. He was admitted with a two-year history of fear, auditory hallucination, learning difficulty, sleeping problems, irascibility, drowsing and giggling. At admission, he had significantly elevated plasma and urine levels of total homocysteine, significantly decreased levels of folate in serum and cerebrospinal fluid, and a normal blood concentration of methionine. Further DNA sequencing analysis showed 665C>T homozygous mutations in the MTHFR gene. The patient was diagnosed with MTHFR deficiency-associated schizophrenia and treatment with calcium folinate, vitamin B12, vitamin B6, and betaine was initiated. After the treatment for 1 week, his plasma and urine levels of homocysteine were decreased to a normal range and the clinical symptoms were significantly improved. After 3 months of treatment, the patient returned to school. He is now living with normal school life. In summary, children with late-onset MTHFR deficiency and secondary cerebral folate deficiency may lead to schizophrenia. This rare condition can be early diagnosed through analyses of blood and urine total homocysteine, amino acids in blood and folate in blood and cerebral fluid and successfully treated with folinic acid, vitamin B6, vitamin B12 and betaine.
Adolescent ; Base Sequence ; Homocystinuria ; complications ; diagnosis ; drug therapy ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2) ; deficiency ; Molecular Sequence Data ; Muscle Spasticity ; complications ; diagnosis ; drug therapy ; Psychotic Disorders ; complications ; diagnosis ; drug therapy ; Schizophrenia ; etiology