Objective: Early onset disorders may have more salient familial/genetic etiology. Neurocognitive deficits which are seen in families of adult onset schizophrenic patients were examined in healthy family members of patients with childhood-onset schizophrenia (COS).
Methods: Trail Making Tests (TMT) A and B, Wechsler Intelligence Scale-Revised Digit Span and Vocabulary subtests were administered to 67 parents and 24 siblings of patients with childhood-onset schizophrenia and 114 healthy community controls (CC) comparable in sex, age, and educational level.
Results: COS siblings performed significantly more poorly than did controls on Trails Making Test B with a trend for poorer performance evident on Trails Making Test A. COS parents performed more poorly than controls only on Trails Making Test A.
Conclusions: Healthy first-degree relatives of COS probands have subtle deficits in tests involving oculomotor/psychomotor speed, working memory and executive function. This provides further support for continuity between COS and later onset schizophrenia and for a familial/genetic factor associated with the illness.