Childhood-onset schizophrenia: smooth pursuit eye-tracking dysfunction in family members
Received 3 March 2004; received in revised form 9 July 2004; accepted 12 July 2004.
Abstract
Background
Childhood-onset schizophrenia (COS), a severe form of the disorder, is of interest for etiologic studies. Smooth pursuit eye-tracking dysfunction (ETD) is a biological marker for schizophrenia.
Aims
To compare familial eye-tracking abnormalities for COS and adult-onset schizophrenia (AOS).
Method
Eye-tracking performance for 70 COS parents, 64 AOS parents and 20 COS siblings was compared to their respective age-matched control groups.
Results
COS and AOS parents had higher rate of dichotomously rated eye-tracking dysfunction than their respective controls (16% vs. 1% and 22% vs. 4%, respectively). COS parents and siblings also differed from controls on several continuous measures. However, scores for COS, AOS and control groups overlapped extensively.
Conclusions
Genetic factors underlying eye-tracking dysfunction appear more salient for COS. However, eye-tracking measures have to be used with caution for endophenotypic definition due to low predictive power.
Declaration of interest
The study was done at the National Institutes of Health.
aChild Psychiatry Branch, National Institute of Mental Health, National Institute of Health, Bldg 10, Rm 3N202, Bethesda, MD 20892, USA
bLaboratory of Clinical Studies, National Institute on Alcohol Abuse and Alcoholism, National Institute of Health, Bldg 10, Rm 3N202, Bethesda, MD 20892, USA
cClinical Brain Disorders Branch, National Institute of Mental Health, National Instituten of Health, Bldg 10, Rm 3N202, Bethesda, MD 20892, USA
ABSTRACT