Olfactory identification and psychosis

Background: Olfactory identification performance has been investigated in s everal psychiatric populations, with deficits most commonly reported in pat ients with schizophrenia, In this study, olfactory identification performan ce was investigated in a more homogenous group of treatment-refractory pati ents 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 a ssessed using the University of Pennsylvania Smell Identification Test (UPS IT) and compared to that of 16 normal control subjects and two other psychi atric patient groups: 19 affective disorder patients requiring maintenance antipsychotic medication and 20 affective disorder patients not receiving a ntipsychotic medication, Results: The olfactory identification performance of T-RS patients was sign ificantly lower than that of normal controls but not significantly differen t from either affective disorder group, The olfactory identification perfor mance 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. (C) 199 9 Society of Biological Psychiatry.