title: Meta-analysis of olfactory function in schizophrenia, first-degree family members, and youths at-risk for psychosis.
abstract: BACKGROUND
  Previous research has provided compelling support for olfactory dysfunction in schizophrenia patients, their first-degree relatives, and youth at-risk for psychosis. A previous meta-analysis revealed large effect sizes across olfactory tasks but was limited to 2 olfactory tasks and did not examine moderator variables. Thus, the current meta-analysis was undertaken to incorporate additional studies, risk cohorts, olfactory test domains, and moderator variable analyses.
  
  
  METHODS
  A meta-analysis was conducted on 67 publications examining olfactory function in schizophrenia patients and 15 publications examining olfactory functioning in youth at-risk for psychosis, first-degree relatives of schizophrenia patients, and individuals with schizotypy.
  
  
  RESULTS
  Results revealed medium-to-large olfactory deficits in schizophrenia patients though significant heterogeneity was evident. Several variables moderated overall study effects. At-risk youths similarly demonstrated medium-to-large effect sizes, whereas first-degree relatives and individuals with schizotypy showed small effects.
  
  
  CONCLUSIONS
  Findings suggest robust olfactory deficits in schizophrenia and at-risk youths. In schizophrenia, several variables had significant impact on these deficits and warrant consideration in prospective studies. Our findings also indicate that olfactory measures may be a useful marker of schizophrenia risk status.
authors: *To whom correspondence should be addressed; 10 Gates, HUP, 3400 Spruce Street, Philadelphia, PA 19104, US; tel: (215) 615-3608, fax: (215) 662-7903, e-mail: moberg@upenn.edu.
authors: Paul J
authors: PJ
authors: Moberg
authors: Vidyulata
authors: V
authors: Kamath
authors: Dana M
authors: DM
authors: Marchetto
authors: Monica E
authors: ME
authors: Calkins
authors: Richard L
authors: RL
authors: Doty
authors: Chang-Gyu
authors: CG
authors: Hahn
authors: Karin E
authors: KE
authors: Borgmann-Winter
authors: Christian G
authors: CG
authors: Kohler
authors: Raquel E
authors: RE
authors: Gur
authors: Bruce I
authors: BI
authors: Turetsky
mesh_terms: D020022:Genetic Predisposition to Disease; D055106:Genome-Wide Association Study; D006801:Humans; D000857:Olfaction Disorders / Q000503:physiopathology*; D011618:Psychotic Disorders / Q000503:physiopathology*; D012559:Schizophrenia / Q000503:physiopathology*; D012569:Schizotypal Personality Disorder / Q000503:physiopathology*
keywords: olfaction; psychosis; schizophrenia prodrome; schizotypy; smell
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