[Psychotic episode due to Hashimoto's thyroiditis]

Abstract

Thyroid hormones are crucial in adult brain metabolic activity. As a result, abnormal thyroid gland function and in particular hypofunction, might cause principally depression and neurocognitive dysfunction. Psychosis, presented mainly with thought disorders and perceptual disturbances, is a much rarer manifestation of hypothyreoidism. A correlation between hypothyreoidism and psychosis has been described since 1888, especially in cases of advanced hypothyreoidism. A few years later (1949), Asher first added the terminology "myxedema madness" to the literature. Psychotic symptoms typically appear after the onset of physical symptoms, usually with a delay of months or years. The case of a female patient who presented a psychotic episode as a first manifestation of hypothyroidism will be described. NE, a 48 yearold female patient, was admitted for the first time to an inpatient mental health care unit due to delusions of persecution and reference, as well as auditory hallucinations that appeared a few weeks ago. After the patient admission, routine laboratory examination was conducted. In order to relieve the patient from her sense of discomfort and while awaiting laboratory results, olanzapine, 5 mg/day, was administered. Neurological examination and cranial computed tomography scan were unremarkable. Hormonal laboratory tests though revealed severe low thyroid hormone levels. Thyroid antibody testing certified Hashimoto's thyroiditis. Olanzapine was discontinued and the patient received thyroid hormone substitution, levothyroxine 75 μg/day, instead. The patient was discharged showing a significant improvement of psychotic symptoms after a 12-day hospitalization. A month later the patient was reevaluated. She had fully recovered from the psychotic episode. A year later, the patient continues to remain free from psychiatric symptoms, while thyroid hormone levels have been restored within normal range. The patient continues receiving only thyroid hormone substitution therapy with levothyroxine. Cases of acute psychosis associated with low levels of thyroid hormones in the context of primary hypothyreoidism have been repeatedly reported. The present case report emphasizes the importance of hypothyroidism exclusion as a secondary cause of psychosis. Thyroid disease treatment ameliorates psychotic disorder symptoms and recovers patients' mental condition.