Organic Psychosis Secondary to Untreated Graves' Disease: A Case Report.

Hyperthyroidism is characterized by elevated circulating thyroid hormone levels with suppressed levels of thyroid-stimulating hormone (TSH). Common manifestations include weight loss, tremor, palpitations, and heat intolerance, while psychosis is a rare neuropsychiatric manifestation. We report the case of a 47-year-old woman who presented with a three-month history of worsening irritability, destructive behavior, irrelevant speech, and multiple delusions, including grandiose, persecutory, and erotomanic types. She also exhibited excessive spending behavior, increased energy, and a reduced need for sleep. Further history revealed symptoms suggestive of untreated hyperthyroidism for three years before presentation. Physical examination showed exophthalmos, goiter, tachycardia, and mild hypertension. Thyroid function tests confirmed thyrotoxicosis, and she was diagnosed with organic psychosis secondary to Graves' disease. Despite treatment with antithyroid medication and beta-blockers, thyrotoxicosis and psychotic symptoms initially persisted. Adjunctive treatment with lithium, combined with psychotropic medication, resulted in marked biochemical and clinical improvement. This report highlights psychosis as a rare manifestation of untreated hyperthyroidism and emphasizes the importance of early recognition and multidisciplinary management involving both endocrinology and psychiatry.