Regional specificity of thalamic volume deficits in male adolescents with early-onset psychosis.

Background Thalamic volume deficits are associated with psychosis but it is unclear whether the volume reduction is uniformly distributed or whether it is more severe in particular thalamic regions. Aims To quantify whole and regional thalamic volume in males with early-onset psychosis and healthy male controls. Method Brain scans were obtained for 80 adolescents: 46 individuals with early-onset psychosis with a duration of positive symptoms less than 6 months and 34 healthy controls. All participants were younger than 19 years. Total thalamic volumes were assessed using FreeSurfer and FSL-FIRST, group comparisons of regional thalamic volumes were studied with a surface-based approach. Results Total thalamic volume was smaller in participants with early-onset psychosis relative to controls. Regional thalamic volume reduction was most significant in the right anterior mediodorsal area and pulvinar. Conclusions In males with minimally treated early-onset psychosis, thalamic volume deficits may be most pronounced in the anterior mediodorsal and posterior pulvinar regions, adding strength to findings from post-mortem studies in adults with psychosis.