title: Subclinical Hypothyroidism after 131I-Treatment of Graves' Disease: A Risk Factor for Depression?
abstract: Although it is well accepted that there is a close relationship between hypothyroidism and depression, previous studies provided inconsistent or even opposite results in whether subclinical hypothyroidism (SCH) increased the risk of depression. One possible reason is that the etiology of SCH in these studies was not clearly distinguished. We therefore investigated the relationship between SCH resulting from 131I treatment of Graves' disease and depression.
  
  
  
  The incidence of depression among 95 patients with SCH and 121 euthyroid patients following 131I treatment of Graves' disease was studied. The risk factors of depression were determined with multivariate logistic regression analysis. Thyroid hormone replacement therapy was performed in patients with thyroid-stimulating hormone (TSH) levels exceeding 10 mIU/L.
  
  
  
  Patients with SCH had significantly higher Hamilton Depression Scale scores, serum TSH and thyroid peroxidase antibody (TPOAb) levels compared with euthyroid patients. Multivariate logistic regression analysis revealed SCH, Graves' eye syndrome and high serum TPO antibody level as risk factors for depression. L-thyroxine treatment is beneficial for SCH patients with serum TSH levels exceeding 10 mIU/L.
  
  
  
  The results of the present study demonstrated that SCH is prevalent among 131I treated Graves' patients. SCH might increase the risk of developing depression. L-thyroxine replacement therapy helps to resolve depressive disorders in SCH patients with TSH > 10mIU/L. These data provide insight into the relationship between SCH and depression.
authors.affiliation: Nuclear Medicine Division, Second Affiliated Hospital, Dalian Medical University, Dalian 116023, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.affiliation: Nuclear Medicine Division, Second Affiliated Hospital, Dalian Medical University, Dalian 116023, China.
authors.forename: Ai-Juan
authors.initials: AJ
authors.lastname: Tian
authors.affiliation: Nuclear Medicine Division, Second Affiliated Hospital, Dalian Medical University, Dalian 116023, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Cell Biology and the Liaoning Provincial Key Laboratory of Cancer Genomics and Epigenetics, College of Basic Medical Sciences, Dalian Medical University, Dalian 116044, China.
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D003863:Depression / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006111:Graves Disease / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy*; D006801:Humans; D007037:Hypothyroidism / Q000150:complications / Q000188:drug therapy* / Q000378:metabolism / Q000532:radiotherapy*; D007453:Iodide Peroxidase / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D013972:Thyrotropin / Q000627:therapeutic use*
chemical_list: D007457:Iodine Radioisotopes; D013972:Thyrotropin; D007453:Iodide Peroxidase