Impaired olfactory identification in relatives of patients with familial schizophrenia

Objective: Impaired olfactory identification ability has previously been de monstrated in patients with schizophrenia. This study assessed olfactory fu nction in psychotic and nonpsychotic members of multigenerational families with familial schizophrenia to determine whether deficits were present in b oth groups. Method: The University of Pennsylvania Smell Identification Test was admini stered birhinally to three groups of subjects aged less than 65 years: 19 p sychotic and 27 nonpsychotic members of families with familial schizophreni a and 43 age-and sex-matched healthy volunteers. Results: Nonpsychotic family members had significantly higher mean Universi ty of Pennsylvania Smell Identification Test scores than psychotic family m embers but were impaired relative to the healthy volunteer group. These gro up differences could not be accounted for by age, sex, or smoking habit. Fi fty-eight percent of the psychotic and 34% of the nonpsychotic family membe rs performed in the microsmic (impaired) range, compared to 9% of the healt hy volunteers. Conclusions: Impaired olfactory deficits may aggregate in families with sch izophrenia and may be indicative of a genetic predisposition to psychosis.