title: Depressive symptoms, thyroid hormone and autoimmunity in a population-based cohort from Sardinia.
abstract: OBJECTIVE
  To evaluate the association between depressive symptoms and thyroid autoimmunity, and the effect of thyroid hormone on the risk of depression.
  
  
  METHODS
  We included 3138 individuals from SardiNIA project, none of whom was taking thyroid medication and antidepressants. Thyrotropin (TSH), free thyroxine (FT4), and antibodies against thyroperoxidase (TPOAb) were measured in all the sample. Depressive symptoms were assessed with Center for Epidemiologic Studies Depression Scale (CES-D).
  
  
  RESULTS
  We found no association between TPOAb and depressive symptoms and no linear association between TSH or FT4 levels and depressive symptoms. However, individuals in the lowest and highest FT4 quintiles showed a higher CES-D score compared to individuals in the middle quintile. In addition, participants in the lowest and highest FT4 quintiles had an increased risk of CES-D≥16 with odds ratios of 1.44 (95% CI=1.09-1.89) and 1.33 (95% CI=1.01-1.77), respectively.
  
  
  CONCLUSIONS
  Cross-sectional design of the study.
  
  
  CONCLUSIONS
  A U-shaped relation was found between FT4 and depressive symptoms: compared to average FT4 values, both high and low thyroid function was associated with more depressive symptoms. Further studies are necessary to determine the exact cause-effect relation of this association.
authors.affiliation: Azienda Ospedaliero-Universitaria di Sassari, Via Michele Coppino 26a, Sassari 07100, Italy. Electronic address: aledelitala@tiscali.it.
authors.forename: Alessandro P
authors.initials: AP
authors.lastname: Delitala
authors.affiliation: Department of Geriatrics, Florida State University College of Medicine, 1115 W. Call Street, Tallahassee, FL 32306, USA. Electronic address: antonio.terracciano@med.fsu.edu.
authors.forename: Antonio
authors.initials: A
authors.lastname: Terracciano
authors.affiliation: Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Cagliari, Italy. Electronic address: edoardofiorillo@gmail.com.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Fiorillo
authors.affiliation: Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Cagliari, Italy. Electronic address: v.orru@tiscali.it.
authors.forename: Valeria
authors.initials: V
authors.lastname: Orrù
authors.affiliation: National Institute on Aging, NIH, DHHS, Baltimore, MD, USA. Electronic address: SchlessingerD@grc.nia.nih.gov.
authors.forename: David
authors.initials: D
authors.lastname: Schlessinger
authors.affiliation: Istituto di Ricerca Genetica e Biomedica (IRGB), Consiglio Nazionale delle Ricerche, c/o Cittadella Universitaria di Monserrato, Cagliari, Italy; Department of Biomedical Sciences, Azienda Ospedaliero-Universitaria di Sassari, Sassari, Italy. Electronic address: francesco.cucca@irgb.cnr.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cucca
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D015551:Autoimmunity; D003430:Cross-Sectional Studies; D003863:Depression / Q000276:immunology*; D005260:Female; D006801:Humans; D007453:Iodide Peroxidase / Q000276:immunology; D033862:Iron-Binding Proteins / Q000276:immunology; D007558:Italy; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012306:Risk; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000378:metabolism / Q000503:physiopathology; D013963:Thyroid Hormones / Q000276:immunology*; D013972:Thyrotropin / Q000276:immunology; D013974:Thyroxine / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D033862:Iron-Binding Proteins; D013963:Thyroid Hormones; D013972:Thyrotropin; C056658:TPO protein, human; D007453:Iodide Peroxidase; D013974:Thyroxine
keywords: Center for Epidemiologic Studies Depression Scale; Depression; Depressive symptoms; Free thyroxine; Thyroid hormone