title: Triiodothyronine may be possibly associated with better cognitive function and less extrapyramidal symptoms in chronic schizophrenia.
abstract: OBJECTIVE
  Many chronic inpatients with schizophrenia demonstrate enduring psychiatric symptoms and various side effects of antipsychotic drugs. Several biological markers such as prolactin, thyroid hormones and brain-derived neurotrophic factor (BDNF) are reportedly associated with psychiatric symptoms and/or antipsychotic side effects in patients with schizophrenia but to date findings are inconsistent. The objective of the present study was to comprehensively investigate the association of psychiatric and extrapyramidal symptoms with hormones and BDNF in chronic schizophrenia.
  
  
  METHODS
  In this study, 93 chronic inpatients with schizophrenia were comprehensively investigated in order to examine the association of psychiatric and extrapyramidal symptoms with prolactin, thyroid hormones (free triiodothyronine (T₃), free thyroxine (T₄), thyroid stimulating hormone), cortisol and BDNF. Symptoms were assessed via the Positive and Negative Syndrome Scale (PANSS), Mini-Mental State Examination (MMSE), and drug-induced extrapyramidal symptoms scale (DIEPSS).
  
  
  RESULTS
  Multiple regression analyses revealed that antipsychotic dose was the only variable that predicted significant variance in PANSS positive subscale scores, that BDNF and free T₃ predicted significant variance in MMSE scores, and that prolactin and free T₃ predicted significant variance in DIEPSS scores.
  
  
  CONCLUSIONS
  These findings suggest that BDNF, free T₃, and prolactin may be associated with cognitive function and/or extrapyramidal symptoms in patients with chronic schizophrenia. Notably, free T₃ may be possibly associated with better cognitive function and less extrapyramidal symptoms, although our cross-sectional study could not reveal a causal relationship.
authors: Department of Neuropsychiatry, Oita University Faculty of Medicine, Japan.
authors: Shugo
authors: S
authors: Ichioka
authors: Takeshi
authors: T
authors: Terao
authors: Nobuhiko
authors: N
authors: Hoaki
authors: Takuo
authors: T
authors: Matsushita
authors: Takayuki
authors: T
authors: Hoaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000009:adverse effects; D001480:Basal Ganglia Diseases / Q000097:blood / Q000150:complications / Q000175:diagnosis / Q000523:psychology; D019208:Brain-Derived Neurotrophic Factor / Q000097:blood; D002908:Chronic Disease; D003071:Cognition / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D011388:Prolactin / Q000097:blood; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014284:Triiodothyronine / Q000097:blood / Q000502:physiology*
chemical_list: D014150:Antipsychotic Agents; D019208:Brain-Derived Neurotrophic Factor; D014284:Triiodothyronine; D011388:Prolactin; D013972:Thyrotropin; D013974:Thyroxine; D006854:Hydrocortisone