Reversible Thyroid Dysfunction Associated With Quetiapine Use in an Adolescent Patient: A Case Report.

Hypothyroidism frequently manifests with neuropsychiatric symptoms that may overlap with primary psychiatric disorders. Quetiapine, an atypical antipsychotic commonly used in mood and psychotic disorders, is generally well tolerated but has been associated with metabolic disturbances and, less commonly, thyroid dysfunction such as subclinical hypothyroidism. We report the case of an adolescent female treated with quetiapine for mood instability and suicidality, who developed elevated thyroid-stimulating hormone (TSH) levels and dyslipidemia despite remaining clinically euthyroid. Dose reduction and eventual discontinuation of quetiapine led to normalization of thyroid function and lipid profile, while psychiatric stability was maintained. Possible mechanisms for quetiapine-induced thyroid dysfunction include dopamine receptor antagonism affecting TSH regulation, direct thyroid effects, and metabolic changes related to weight gain. This case highlights the necessity for routine monitoring of thyroid and metabolic parameters during quetiapine therapy to ensure optimal management of psychiatric symptoms while minimizing endocrine complications.