Cortical Morphology Characteristics of Young Offspring of Patients With Schizophrenia or Bipolar Disorder

Objective: Cortical surface area and thickness abnormalities have been observed in patients with schizophrenia and bipolar disorders; however, no study thus far has examined cortical morphologic measurements in children and adolescents at genetic risk for the disorders comparatively. Method: One hundred thirty-seven participants, including 36 offspring of patients with schizophrenia (SzO), 54 offspring of patients with bipolar disorder (BpO), and 47 offspring of community controls (CcO), 6 to 17 years old, were assessed with clinical and neuroimaging methods. Sixty-nine percent of the sample was reassessed at a 27.6-month (mean) follow-up. Cortical surface reconstruction was applied to measure cortical area and thickness using FreeSurfer; mixed-effects models were used to investigate cross-sectional and longitudinal differences in global and lobar morphologic measurements. Results: The SzO group exhibited a cross-sectional decrease in global, parietal, and occipital lobe surface area compared with the CcO group, and in the occipital lobe compared with the BpO group. In the SzO group, global and parietal surface area values were inversely associated with attenuated positive and negative prodromal symptom scores. No cross-sectional differences in cortical thickness were observed. Division of the sample by pubertal status showed group-by-time interactions in the pubertal and postpubertal SzO subgroup, with less longitudinal decrease in cortical surface area and thickness than in the CcO and BpO subgroups, respectively. Conclusion: The SzO, but not the BpO, group was characterized by cross-sectional decreases in surface area, and this was associated with prodromal symptoms. Longitudinal changes in cortical morphology associated with risk for schizophrenia may be expressed differently according to developmental stage.