Background: Olfactory identification performance has been investigated in several psychiatric populations, with deficits most commonly reported in patients with schizophrenia. In this study, olfactory identification performance was investigated in a more homogenous group of treatment-refractory patients with schizophrenia (T-RS) and in two additional psychiatric groups who demonstrate some similarities to the patients with schizophrenia in terms of symptomotology and medication regime.
Methods: The olfactory identification performance of 16 T-RS patients was assessed using the University of Pennsylvania Smell Identification Test (UPSIT) and compared to that of 16 normal control subjects and two other psychiatric patient groups: 19 affective disorder patients requiring maintenance antipsychotic medication and 20 affective disorder patients not receiving antipsychotic medication.
Results: The olfactory identification performance of T-RS patients was significantly lower than that of normal controls but not significantly different from either affective disorder group. The olfactory identification performance of affective disorder patients receiving antipsychotic medication was significantly lower than that of affective disorder patients not receiving antipsychotic medication.
Discussion: Results are discussed in the context of a possible link between psychotic symptomotology and olfactory identification performance.