Sex-related differences in smell identification have been shown in healthy subjects, however, in patients with schizophrenia these findings are still controversial.

We analyzed sex-related differences with respect to smell identification in patients with schizophrenia, their first-degree relatives and healthy controls.

To assess possible sex-related differences in smell identification.

The sample consisted of 51 patients with schizophrenia-spectrum disorders (49% female; mean age 33.1 years; SD: 11), 21 first-degree relatives (61.9% female, age 49.5 years, SD 17.6, one affected, others non-affected) ; mean age 49.5 years; SD: 17.6) and 51 matched healthy controls (49% female; mean age 33 years; SD: 12.1). The Positive and Negative Syndrome Scale (PANSS) and the Mini International Neuropsychiatric Interview (M.I.N.I.) were used to assess psychopathology and diagnosis, respectively. The University of Pennsylvania Smell Identification Test (UPSIT), a standardized, multiple- and forced-choice scratch- and sniff test consisting of 40 items, was administered to all subjects.

We found no significant differences in smell identification between the three groups (p = 0.182). Also, the female and male subgroups did not differ significantly in smell identification (p = 0.105, p = 0.387, respectively). The mean UPSIT scores were 34.4 (SD: 4.1) for healthy women (males: 33.2; SD: 3.5), 32.0 (SD: 5.1) for women with schizophrenia-spectrum disorders (males: 32.5; SD: 4.4), and 34.5 (SD: 2.6) for female first-degree relatives (males: 30.5; SD: 2.8).

We found neither significant differences in smell identification in patients with schizophrenia-spectrum disorders, their first-degree relatives or healthy controls, nor sex-related differences.