title: Reduced orexin levels in the cerebrospinal fluid of suicidal patients with major depressive disorder.
abstract: Orexins are neuropeptides selectively expressed in a small number of neurons in the lateral-posterior hypothalamus. We measured orexin-A in the cerebrospinal fluid (CSF) of 66 patients with major depressive disorder (MDD), dysthymia and adjustment disorder after a suicide attempt. Blood samples confirmed that the patients were free from antidepressive and neuroleptic medication at the time of the lumbar punctures. CSF levels of orexin-A were significantly lower in patients with MDD than in patients with adjustment disorder and dysthymia. Orexin correlated significantly with CSF levels of somatostatin, delta sleep inducing peptide-like immunoreactivity (DSIP-LI) and corticotrophin releasing factor (CRF), but not with leptin or vasopressin. Plasma levels of thyroid-stimulating hormone (TSH) were not reduced in MDD patients, and did not correlate with CSF-orexin. Our results suggest that suicidal patients with MDD have distinct neurobiological features, involving compromised levels of hypothalamic peptides regulating the state of arousal.
authors.affiliation: Division of Psychiatry, Department of Clinical Sciences, Lund University, Kioskgatan 19, SE-221 85 Lund, Sweden. Lena.Brundin@med.lu.se
authors.forename: Lena
authors.initials: L
authors.lastname: Brundin
authors.forename: Maria
authors.initials: M
authors.lastname: Björkqvist
authors.forename: Asa
authors.initials: A
authors.lastname: Petersén
authors.forename: Lil
authors.initials: L
authors.lastname: Träskman-Bendz
mesh_terms: D000275:Adjustment Disorders / Q000134:cerebrospinal fluid; D000328:Adult; D000367:Age Factors; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism; D003701:Delta Sleep-Inducing Peptide / Q000378:metabolism; D003865:Major Depressive Disorder / Q000134:cerebrospinal fluid* / Q000523:psychology*; D015536:Down-Regulation / Q000502:physiology*; D019263:Dysthymic Disorder / Q000134:cerebrospinal fluid; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D009479:Neuropeptides / Q000134:cerebrospinal fluid*; D000068797:Orexins; D011863:Radioimmunoassay; D012737:Sex Factors; D013004:Somatostatin / Q000378:metabolism; D018709:Statistics, Nonparametric; D013405:Suicide
chemical_list: C000596229:HCRT protein, human; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D013004:Somatostatin; D003701:Delta Sleep-Inducing Peptide; D003346:Corticotropin-Releasing Hormone