General absence of abnormal cortical asymmetry in childhood-onset schizophrenia: A longitudinal study

Background: Childhood-onset schizophrenia (COS) is a rare, severe form of the adult-onset illness, with more salient neurobiological causes. Previous cross-sectional structural neuroimaging research has suggested that normal cortical asymmetry patterns [(R - L/(R + L)] may be altered in adult schizophrenia, although these findings were not well replicated. Recent studies show dynamic changes in brain asymmetry during childhood and adolescence. We hypothesized that COS patients would show a lack of normal development of asymmetry and decreased overall asymmetry. Methods: Prospective structural magnetic resonance scans were obtained at baseline and at two-year follow-up visits in 49 right-handed COS patients (mean baseline age: 14.72 +/- 2.63, 117 scans) and 50 age and sex-matched, right-handed healthy controls (mean baseline age: 15.15 +/- 3.37, 125 scans). Cortical thickness was calculated at 40,962 homologous points across each cerebral hemisphere using a fully automated, validated method. Differences in developmental asymmetry patterns across the cortical surface were analyzed using a linear mixed effects regression model. Results: No significant asymmetry differences were found either for cross-sectional comparisons of COS and healthy controls across the lateral and medial cortical surfaces or with respect to timing of developmental changes in asymmetry. Conclusions: The present findings do not support asymmetry differences for this severe, early form of schizophrenia. Published by Elsevier B.V.