Depression of the elderly revealing a primary hypothyroidism

Abstract

Introduction       Psychiatric manifestations are exceptional during hypothyroidism and are not always easy to diagnose, especially since the clinical signs of hypothyroidism can be confused with those of the depressive syndrome. We report an original observation of depression of the elderly revealing an isolated primary hypothyroidism. 
Observation       A 78-year-old patient, followed for essential hypertension, well-balanced under monotherapy with calcium channel blockers, and without degenerative complications, was referred by her family doctor for depressive syndrome not improved by the specific treatment prescribed and correctly taken for six months. The clinical examination noted in particular macroglossia with dental impressions and dry and cracked skin. The biological assessment showed hypothyroidism with TSH at 28 μmol/l. Thyroid ultrasound showed atrophy of the thyroid gland. The thyroid autoimmunity (anti-thyroglobulin and anti-thyroperoxidase antibodies) was negative. The rest of the biological tests were in the normal range. The diagnosis of Riedel’s thyroiditis was retained and the patient was treated with levothyroxine in progressive doses until TSH normalization was achieved. The evolution on the psychiatric level was also favorable with disappearance of the signs of the depression and the anti-depressive treatment was discontinued. 
Conclusion       Depression is rare, complicating only 4% of overt hypothyroidism and its diagnosis is not always easy, especially in the elderly. Hormone replacement therapy significantly improves the depressive syndrome and protects against cognitive decline. Thus, hypothyroidism screening seems appropriate for any depressive syndrome in the elderly.