title: Lack of correlation between cerebrospinal fluid thyrotropin-releasing hormone (TRH) and TRH-stimulated thyroid-stimulating hormone in patients with depression.
abstract: BACKGROUND
  It has been proposed that elevated central thyrotropin-releasing hormone (TRH) is associated with the blunted thyroid-stimulating hormone (TSH) response to TRH in patients with depression. Few studies have directly evaluated this relationship between central nervous system and peripheral endocrine systems in the same patient population.
  
  
  METHODS
  15 depressed patients (4 male, 11 female, 12 bipolar, and 3 unipolar) during a double-blind, medication-free period of at least 2 weeks duration, underwent a baseline lumbar puncture followed by a TRH stimulation test. Cerebrospinal fluid (CSF) TRH and serial serum TSH, free thyroxine, triiodothyronine, prolactin, and cortisol were measured. A blunted response to TRH was defined as a delta TSH less than 7 microU/mL.
  
  
  RESULTS
  There was no significant difference in mean CSF TRH between "blunters" (2.82 +/- 1.36 pg/mL) and "non-blunters" (3.97 +/- 0.62 pg/mL, p = .40). There was no evidence of an inverse relationship between CSF TRH and baseline or delta TSH. There was no correlation between CSF TRH and the severity of depression or any other endocrine measure.
  
  
  CONCLUSIONS
  These data are not consistent with the prediction of hypothalamic TRH hypersecretion and subsequent pituitary down-regulation in depression; however, CSF TRH may be from a nonparaventricular nucleus-hypothalamic source (i.e., limbic area, suprachiasmatic nucleus, brain stem-dorsal raphe) and thus, not necessarily related to peripheral neuroendocrine indices.
authors.affiliation: National Institute of Mental Health, Biological Psychiatry Branch, Bethesda, MD 20892, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Frye
authors.forename: R T
authors.initials: RT
authors.lastname: Dunn
authors.forename: K A
authors.initials: KA
authors.lastname: Gary
authors.forename: T A
authors.initials: TA
authors.lastname: Kimbrell
authors.forename: A M
authors.initials: AM
authors.lastname: Callahan
authors.forename: D A
authors.initials: DA
authors.lastname: Luckenbaugh
authors.forename: G
authors.initials: G
authors.lastname: Corá-Locatelli
authors.forename: E
authors.initials: E
authors.lastname: Vanderham
authors.forename: A
authors.initials: A
authors.lastname: Winokur
authors.forename: R M
authors.initials: RM
authors.lastname: Post
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000134:cerebrospinal fluid*; D003866:Depressive Disorder / Q000134:cerebrospinal fluid*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000134:cerebrospinal fluid; D008297:Male; D011388:Prolactin / Q000134:cerebrospinal fluid; D013972:Thyrotropin / Q000134:cerebrospinal fluid* / Q000378:metabolism*; D013973:Thyrotropin-Releasing Hormone / Q000134:cerebrospinal fluid* / Q000494:pharmacology*; D013974:Thyroxine / Q000134:cerebrospinal fluid; D014284:Triiodothyronine / Q000134:cerebrospinal fluid
chemical_list: D014284:Triiodothyronine; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D013972:Thyrotropin; D013974:Thyroxine; D006854:Hydrocortisone