The thalamus and the schizophrenia phenotype: Failure to replicate reducedvolume

Background: Thalamic abnormalities resulting ill impaired attention and inf ormation processing may form a foundation for cognitive and perceptual dist urbances in schizophrenia, Measurements of the thalamus in patients with sc hizophrenia have shown reductions relative to normal comparison subjects, Methods: In the current project, magnetic resonance images of the brain wer e obtained in 10 male and 11 female subjects with paranoid-type schizophren ia, and 15 male and 12 female normal comparison subjects, Total brain and b ilateral thalamic volumes were calculated. Results: There were no significant diagnosis, hemisphere, or gender differe nces in thalamic volumes. Conclusions: Structural thalamic abnormalities are not likely to universall y and parsimoniously explain the schizophrenia phenotype. Abnormal thalamic size in patients with schizophrenia should be understood as reflecting one of several possible structural abnormalities contributing to production of the schizophrenia phenotype, but mist be regarded with caution unless pail ed with functional studies. Biol Psychiatry 1999;45:1329-1335 (C) 1999 Soc iety of Biological Psychiatry.