Olfactory Identification May Be Linked to Social, Cognitive Functioning in Schizophrenia
Worse cognitive and social functioning in patients with schizophrenia was associated with worse olfactory identification.
Performance in olfactory identification (OI) is related to both cognitive and social cognitive function, according to a study published in Psychiatry Research. All 3 domains evidenced impairment in patients with schizophrenia vs control patients.
Olfactory dysfunction has been documented in patients with schizophrenia. It depends on the maturation of frontal and temporal lobe areas, the same regions of the brain involved in cognitive and social functioning.
The researchers investigated OI differences in patients vs controls in relationship to social and cognitive function. Cross-sectional data was collected from a longitudinal study, the Genetic Risk and Outcome in Psychosis (GROUP) project. One-hundred thirty-two patients with schizophrenia and 128 healthy control patients were included in the analyses. The Sniffin' Sticks task was used to assess OI performance, and a questionnaire was administered regarding childhood and adolescent social and social cognitive function. Present state social cognitive and cognitive function was assessed as well.
Regarding present state cognition and social cognition, a significant main effect on OI was evidenced in patients vs controls (β, 0.127 [P =.044] and β, 0.132 [P =.034], respectively).
In addition, a significant association between lower cognitive and social cognitive scores and decreased OI performance was evidenced after correction for false discovery rate (FDR; β, 0.200 [P =.003] and β, 0.277 [P <.001], respectively).
Regarding childhood and adolescent cognition and social cognition, a significant main effect on OI was also evidenced in patients with schizophrenia vs controls (β, 0.143; P =.021).
In addition, a significant association between cognitive and social cognitive functioning in childhood and adolescence with OI performance was evidenced after FDR correction (β, −0.193 [P =.003] and β, −0.228 [P =.001], respectively).
Overall, performance on OI was reduced in patients with schizophrenia vs control patients (P =.021). Furthermore, patients evidenced decreased performance in childhood and adolescence cognitive and social functioning (P =.003 and .001, respectively), as well as present state cognitive and social cognitive function (P =.003 and <.001).
"In this study, findings of worse OI in patients relative to controls were replicated," the authors wrote. Although the assessment of childhood and adolescent parameters was limited by its retrospective design, the authors noted that "[t]he most original and novel finding of our study is that social and cognitive functioning in childhood/adolescence and present state social cognition domains...are related to OI."
Disclosures: Multiple authors declare affiliations with the pharmaceutical industry.
de Nijs J, Meijer JH, de Haan L, et al. Associations between olfactory identification and (social) cognitive functioning: A cross-sectional study in schizophrenia patients and healthy controls. Psychiatry Res. 2018;266:147-151.