Olfactory function and schizophrenia: an update

Abstract

Olfaction is a field of growing interest in schizophrenia research. This article reviews recent studies on olfactory functions in schizophrenia. The current literature provides additional insights into olfactory deficits, abnormalities, and olfactory hedonic dysfunction in schizophrenia. Recent findings reinforce particular associations with negative symptoms and deficit syndrome schizophrenia. Studies indicate that abnormalities in patients with schizophrenia extend to more peripheral olfactory structures and functions, including olfactory receptor neuron dysfunction. Olfactory identification ability was found to relate to prodromal disorganization symptoms in young high-risk patients. Further support for the notion of a genetic contribution to olfactory dysfunction in schizophrenia derives from studies reporting physiological olfactory dysfunction (olfactory event-related potentials) in unaffected relatives, and an odor-specific hyposmia, present in both patients with schizophrenia and family members. Further research is needed to improve our understanding of olfactory dysfunction in schizophrenia. Recent encouraging findings underscore that the olfactory system is a field of research that holds promise for advancing our understanding of the pathophysiology of schizophrenia and possibly as a useful endophenotypic marker of neurodevelopmental vulnerability.