Negative symptoms of schizophrenia correlate with impairment on the University of Pennsylvania Smell Identification Test

Abstract

Deficits in odor identification have been the 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 predict 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.

Olfactory identification deficits at identification as ultra-high risk for psychosis are associated with poor functional outcome

“…Kayser et al, 2013;Turetsky et al, 2008), allow sensory information to reach orbitofrontal regions (Brewer et al, 2006). This hypothesis is supported by the findings that OI deficits are associated with negative symptoms (Brewer et al, 1996a(Brewer et al, , 2001Corcoran et al, 2005;Good et al, 2006;Ishizuka et al, 2010) and more specifically, the deficit syndrome of schizophrenia (Strauss et al, 2010).…”

Olfactory performance segregates effects of anhedonia and anxiety on social function in patients with schizophrenia

“…Links between loss of smell, anhedonia and reduced quality of life have been recently described, 42,43 as has an asso ciation between anhedonia and decreased performance on smell identification. 21 Increased ability to identify the origins of odours may heighten vigilance and produce fear in individuals unable to use higherlevel processes to evaluate the context of the sen sory experience. The amygdala plays central roles in both odour perception and response to aversive stimuli and in the awareness and expression of fear.…”

“…A recent study of college students demonstrated better SIT performance for those with elevated social anhedonia, 20 but another study conversely found lesser performance for individuals with anhedonia, blunted affect and apathy, 21 con sistent with the results in patients with schizophrenia. The as sociation between olfaction and anxiety is unstudied in pa tients with schizophrenia, but SIT deficits have been found in patients with obsessive-compulsive disorder (OCD) 22 and posttraumatic stress disorder (PTSD).…”

Objective and Subjective Olfaction Across the Schizophrenia Spectrum

“…Given the magnitude of this deficit, it has been proposed that olfaction deficits also reflect a vulnerability marker for schizophrenia-spectrum disorders. Related to this, there is a strong background of existing literature that links negative symptoms of schizophrenia to olfaction accuracy (Ishizuka et al, 2010). Often, negative symptoms are specifically linked to the first episode of psychosis (Corcoran et al, 2005).…”