Meta-analysis of olfactory function in schizophrenia, first-degree family members, and youths at-risk for psychosis

Schizophr Bull. 2014 Jan;40(1):50-9. doi: 10.1093/schbul/sbt049. Epub 2013 May 2.


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.

Method: 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.

Keywords: olfaction; psychosis; schizophrenia prodrome; schizotypy; smell.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural

MeSH terms

  • Genetic Predisposition to Disease*
  • Genome-Wide Association Study
  • Humans
  • Olfaction Disorders / physiopathology*
  • Psychotic Disorders / physiopathology*
  • Schizophrenia / physiopathology*
  • Schizotypal Personality Disorder / physiopathology*