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

• Published in: Schizophrenia research Vol. 161; no. 2; pp. 156 - 162
• Main Authors: Lin, A, Brewer, W.J, Yung, A.R, Nelson, B, Pantelis, C, Wood, S.J
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2015
• Subjects: Adult; At-risk; Disease Progression; Female; Humans; Longitudinal; Longitudinal Studies; Male; Mental Status Schedule; Olfaction; Olfaction Disorders - physiopathology; Olfaction Disorders - psychology; Olfactory identification; Orbitofrontal cortex; Psychiatry; Psychosis; Psychotic Disorders - diagnosis; Psychotic Disorders - psychology; Risk Assessment; Schizophrenia; Severity of Illness Index; Smell; Smell - physiology; Ultra-high risk; Young Adult; Olfactory identification; Psychosis; Orbitofrontal cortex; Longitudinal; Olfaction; Schizophrenia; Ultra-high risk; Smell; At-risk
• ISSN: 0920-9964; 1573-2509
• DOI: 10.1016/j.schres.2014.10.051

Abstract Background We have previously reported that olfactory identification (OI) deficits are a promising premorbid marker of transition from ultra-high risk (UHR) to schizophrenia, but not to psychotic illness more generally. Whether this remains the case at longer follow-up, and whether there is decline in OI ability are unclear. Method The University of Pennsylvania Smell Identification Test (UPSIT) was administered to 81 participants at baseline (identification of risk for psychosis) and 254 individuals at follow-up. Forty-nine participants underwent UPSIT assessment at both time points. UPSIT scores were investigated at an average of 7.08 years after identification of risk in relation to transition to psychosis, a diagnosis of schizophrenia, and psychosocial/functional outcome. Results UPSIT scores at baseline and follow-up did not differ between participants who transitioned to psychosis and those who did not. Similarly, there were no significant differences on UPSIT scores at baseline or follow-up between individuals with a diagnosis of schizophrenia and transitioned individuals without schizophrenia. Those with a poor functional outcome showed significantly lower baseline UPSIT scores than participants with good outcome. There was no significant association between functional outcome and follow-up UPSIT scores. There were no significant changes in UPSIT over time for any group. Conclusions These results suggest that impaired OI is not a good marker of the onset of psychosis and schizophrenia, but may differentiate UHR individuals who experience a poor functional outcome, regardless of transition status.