title: Negative symptoms of schizophrenia correlate with impairment on the University of Pennsylvania smell identification test.
abstract: Deficits in odor identification have been most frequently described in schizophrenia (SZ). A relationship between dysfunction in odor identification and negative symptoms of SZ has also been reported. Furthermore, deficit SZ (a subtype of the illness with primary, enduring negative symptoms) has been found to be associated with a particularly poor performance on odor identification tests indicating that deficits in smell identification could be differentially expressed in some subtypes of SZ. We describe correlations of performance on smell identification with positive and negative symptoms of SZ. Patients with SZ (n=15) and normal controls (n=19) were tested by the University of Pennsylvania Smell Identification Test (UPSIT). Psychopathology was assessed with the Scales for the Assessment of Positive and Negative Symptoms (SAPS and SANS). SZ patients performed more poorly on the UPSIT test than did normal controls. Consistent with previous findings, we observed a correlation of SANS with UPSIT performance. In particular, specific subdomains of SANS, such as blunted affect, apathy and anhedonia, were associated with odor identification deficits. Furthermore, UPSIT score predicts these subdomains of negative symptoms. No correlation was observed between positive symptom and odor identification deficits. Our study further reinforces a relation between olfactory identification deficit and negative symptoms in SZ and suggests that smell identification could be a candidate endophenotype relevant to negative symptoms of SZ.
authors.affiliation: Department of Psychiatry, Johns Hopkins University School of Medicine, United States.
authors.forename: Koko
authors.initials: K
authors.lastname: Ishizuka
authors.forename: Katsunori
authors.initials: K
authors.lastname: Tajinda
authors.forename: Carlo
authors.initials: C
authors.lastname: Colantuoni
authors.forename: Masahiko
authors.initials: M
authors.lastname: Morita
authors.forename: Jessica
authors.initials: J
authors.lastname: Winicki
authors.forename: Cindy
authors.initials: C
authors.lastname: Le
authors.forename: Sandra
authors.initials: S
authors.lastname: Lin
authors.forename: David
authors.initials: D
authors.lastname: Schretlen
authors.forename: Akira
authors.initials: A
authors.lastname: Sawa
authors.forename: Nicola G
authors.initials: NG
authors.lastname: Cascella
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009812:Odorants; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000209:etiology*; D011569:Psychiatric Status Rating Scales; D012044:Regression Analysis; D012559:Schizophrenia / Q000150:complications*; D012903:Smell / Q000502:physiology*; D013997:Time Factors