title: Cerebrospinal fluid hypocretin-1 (orexin A) levels in mania compared to unipolar depression and healthy controls.
abstract: BACKGROUND
  Impairment of sleep-wake cycles and circadian rhythm are found in human narcolepsy which is characterized by deficiency of hypocretin (hcrt) or its receptors. A disturbed electroencephalography (EEG) based vigilance regulation is also found in affective disorders such as major depressive disorder (MDD) and mania. For the first time, in the present study hcrt levels were investigated in patients with a manic episode and compared with age-matched patients with MDD and controls.
  
  
  METHODS
  15 subjects were enrolled in the study after admission to hospital: 5 manic (mean YMRS 15.6+/-2.9) and 5 age-matched patients with MDD (mean HDRS 11.6+/-8.0), and 5 age-matched controls without any neurological or psychiatric disorder. Cerebrospinal fluid (CSF) hcrt levels were measured in all three groups using a fluorescence immunoassay (FIA).
  
  
  RESULTS
  Mean hcrt-1 level in manic patients (77.3+/-20.7 pg/ml) did not differ significantly compared to patients with MDD (75.6+/-15.7 pg/ml MDD) or controls (74.9+/-19.3 pg/ml). Hcrt levels and severity of disease did not show a significant association.
  
  
  CONCLUSIONS
  In the present study, for the first time hcrt-1 levels in manic patients were investigated but did not reveal significant differences neither compared to age-matched patients with MDD nor healthy controls without any psychiatric or neurological disorder.
authors.affiliation: Department of Psychiatry and Psychotherapy, University Hospital Leipzig, Semmelweisstr 10, 04103 Leipzig, Germany.
authors.forename: Frank M
authors.initials: FM
authors.lastname: Schmidt
authors.forename: Matthias
authors.initials: M
authors.lastname: Brügel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kratzsch
authors.forename: Maria
authors.initials: M
authors.lastname: Strauss
authors.forename: Christian
authors.initials: C
authors.lastname: Sander
authors.forename: Petra
authors.initials: P
authors.lastname: Baum
authors.forename: Joachim
authors.initials: J
authors.lastname: Thiery
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hegerl
authors.forename: Peter
authors.initials: P
authors.lastname: Schönknecht
mesh_terms: D001714:Bipolar Disorder / Q000134:cerebrospinal fluid*; D003865:Major Depressive Disorder / Q000134:cerebrospinal fluid*; D005260:Female; D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D008297:Male; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D000068797:Orexins; D012720:Severity of Illness Index
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins