Impaired olfactory identification in relatives of patients with familial schizophrenia.
OBJECTIVE
Impaired olfactory identification ability has previously been demonstrated in patients with schizophrenia. This study assessed olfactory function in psychotic and nonpsychotic members of multigenerational families with familial schizophrenia to determine whether deficits were present in both groups.


METHODS
The University of Pennsylvania Smell Identification Test was administered birhinally to three groups of subjects aged less than 65 years: 19 psychotic and 27 nonpsychotic members of families with familial schizophrenia and 43 age- and sex-matched healthy volunteers.


RESULTS
Nonpsychotic family members had significantly higher mean University of Pennsylvania Smell Identification Test scores than psychotic family members but were impaired relative to the healthy volunteer group. These group differences could not be accounted for by age, sex, or smoking habit. Fifty-eight percent of the psychotic and 34% of the nonpsychotic family members performed in the microsmic (impaired) range, compared to 9% of the healthy volunteers.


CONCLUSIONS
Impaired olfactory deficits may aggregate in families with schizophrenia and may be indicative of a genetic predisposition to psychosis.
Kopala
L C
LC
Department of Psychiatry, Dalhousie University, 5909 Veterans' Memorial Lane, Halifax, Nova Scotia, Canada B3H 2E2. lkopala@is.dal.ca
Good
K P
KP
Morrison
K
K
Bassett
A S
AS
Alda
M
M
Honer
W G
WG
D000328:Adult; D005190:Family; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D000857:Olfaction Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D011601:Psychophysics; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology / Q000235:genetics*; D012684:Sensory Thresholds / Q000502:physiology; D012720:Severity of Illness Index; D012903:Smell / Q000502:physiology