title: Hyperthyroidism and psychiatric morbidity: evidence from a Danish nationwide register study.
abstract: OBJECTIVE
  Thyroid hormones are essential for the normal development of the fetal brain, while hyperthyroidism in adults is associated with mood symptoms and reduced quality of life. In this study, we aimed to investigate the association and temporal relationship between hyperthyroidism and psychiatric morbidity.
  
  
  METHODS
  Register-based nationwide cohort study.
  
  
  METHODS
  Data on hyperthyroidism and psychiatric morbidity were obtained by record linkage of the Danish National Patient Registry and the Danish National Prescription Registry. A total of 2631 hyperthyroid individuals were identified and matched 1:4 with non-hyperthyroid controls and followed for a mean duration of 6 years (range 0-13). Logistic and Cox regression models were used to assess the risk of psychiatric morbidity before and after the diagnosis of hyperthyroidism respectively.
  
  
  RESULTS
  BEFORE THE DIAGNOSIS OF HYPERTHYROIDISM, SUCH INDIVIDUALS HAD AN INCREASED RISK OF BEING HOSPITALIZED WITH PSYCHIATRIC DIAGNOSES (ODDS RATIO (OR): 1.33; 95% CI: 0.98-1.80) and an increased risk of being treated with antipsychotics (OR: 1.17; 95% CI: 1.00-1.38), antidepressants (OR: 1.13; 95% CI: 1.01-1.27), or anxiolytics (OR: 1.28; 95% CI: 1.16-1.42). After the diagnosis of hyperthyroidism, there was a higher risk of being hospitalized with psychiatric diagnoses (hazard ratio (HR): 1.51; 95% CI: 1.11-2.05) and an increased risk of being treated with antipsychotics (HR: 1.46; 95% CI: 1.20-1.79), antidepressants (HR: 1.54; 95% CI: 1.36-1.74), or anxiolytics (HR: 1.47; 95% CI: 1.27-1.69).
  
  
  CONCLUSIONS
  Hyperthyroid individuals have an increased risk of being hospitalized with psychiatric diagnoses and being treated with antipsychotics, antidepressants, and anxiolytics, both before and after the diagnosis of hyperthyroidism.
authors.affiliation: Department of Endocrinology and Metabolism, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: Frans
authors.initials: F
authors.lastname: Brandt
authors.forename: Marianne
authors.initials: M
authors.lastname: Thvilum
authors.forename: Dorthe
authors.initials: D
authors.lastname: Almind
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
authors.forename: Anders
authors.initials: A
authors.lastname: Green
authors.forename: Laszlo
authors.initials: L
authors.lastname: Hegedüs
authors.forename: Thomas Heiberg
authors.initials: TH
authors.lastname: Brix
mesh_terms: D000328:Adult; D000368:Aged; D014151:Anti-Anxiety Agents / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D015331:Cohort Studies; D015897:Comorbidity; D003718:Denmark / Q000453:epidemiology; D004200:Diseases in Twins / Q000453:epidemiology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006980:Hyperthyroidism / Q000453:epidemiology*; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy / Q000453:epidemiology*; D008875:Middle Aged; D016016:Proportional Hazards Models; D012042:Registries
chemical_list: D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D014150:Antipsychotic Agents