title: Effects of adjunctive intranasal oxytocin on olfactory identification and clinical symptoms in schizophrenia: results from a randomized double blind placebo controlled pilot study.
abstract: BACKGROUND
  Deficits in olfactory identification have been widely reported in patients with schizophrenia (SZ) and are associated with negative symptomatology. Adjunctive oxytocin delivered intranasally has been shown to improve some aspects of social cognition as well as positive and negative symptoms in patients with schizophrenia. Given the intranasal delivery route of oxytocin to olfactory pathways and that olfactory abnormalities are a potential endophenotype in SZ, we investigated the effect of intranasal oxytocin on olfactory identification as well as positive and negative symptoms in people with schizophrenia.
  
  
  METHODS
  Individuals with schizophrenia or schizoaffective disorder (n=28; 16 outpatients, 12 inpatients) were randomized to receive adjunctive intranasal oxytocin 20 IU BID or placebo for 3 weeks.
  
  
  RESULTS
  All 28 participants completed the clinical trial. Odor identification performance significantly improved on the University of Pennsylvania Smell Identification Test (UPSIT) total score and subscore for pleasant smells. UPSIT score (F=5.20, df=1,23, p=0.032) and subscore for pleasant smells (F=4.56, df=1,23, p=0.044), in patients treated with oxytocin were compared to placebo from baseline to endpoint. Global symptomatology as well as positive and negative symptoms were not improved by intranasal oxytocin. In fact, global symptoms, not positive or negative symptoms, improved in the placebo group. Secondary analysis shows that intranasal oxytocin improved negative symptoms in the small group of inpatients. Intranasal oxytocin was well tolerated during the three week trial.
  
  
  CONCLUSIONS
  Adjunctive intranasal oxytocin may improve olfactory identification, particularly in items of positive valence. Larger studies are needed to determine the effects of oxytocin on negative symptoms in SZ. (NCT00884897; http://www.clinicaltrials.gov).
authors: Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, Baltimore, MD 21224, USA. leemary@mail.nih.gov
authors: Mary R
authors: MR
authors: Lee
authors: Heidi J
authors: HJ
authors: Wehring
authors: Robert P
authors: RP
authors: McMahon
authors: Jared
authors: J
authors: Linthicum
authors: Nicola
authors: N
authors: Cascella
authors: Fang
authors: F
authors: Liu
authors: Alan
authors: A
authors: Bellack
authors: Robert W
authors: RW
authors: Buchanan
authors: Gregory P
authors: GP
authors: Strauss
authors: Carlo
authors: C
authors: Contoreggi
authors: Deanna L
authors: DL
authors: Kelly
mesh_terms: D000281:Administration, Intranasal; D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D014150:Antipsychotic Agents / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000857:Olfaction Disorders / Q000188:drug therapy / Q000209:etiology; D010121:Oxytocin / Q000008:administration & dosage*; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012559:Schizophrenia / Q000150:complications* / Q000188:drug therapy*; D012903:Smell / Q000187:drug effects*; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D010121:Oxytocin