Corpus callosum area in patients with bipolar disorder with and without psychotic features: An international multicentre study

Background: previous studies have reported mri abnormalities of the corpus callosum (cc) in patients with bipolar disorder (bd),although only a few studies have directly compared callosal areas in psychotic versus nonpsychotic patients with this disorder. we sought to compare regional callosal areas in a large international multicentre sample of patients with bd and healthy controls. methods: we analyzed anatomic t1 mri data of patients with bd-i and healthy controls recruited from 4 sites (france,germany,ireland and the united states). we obtained the mid-sagittal areas of 7 cc subregions using an automatic cc delineation. differences in regional callosal areas between patients and controls were compared using linear mixed models (adjusting for age,sex,handedness,brain volume,history of alcohol abuse/dependence,lithium or antipsychotic medication status,symptomatic status and site) and multiple comparisons correction. we also compared regional areas of the cc between patients with bd with and without a history of psychotic features. results: we included 172 patients and 146 controls in our study. patients with bd had smaller adjusted mid-sagittal cc areas than controls along the posterior body,the isthmus and the splenium of the cc. patients with a positive history of psychotic features had greater adjusted area of the rostral cc region than those without a history of psychotic features. limitations: we found small to medium effect sizes,and there was no calibration technique among the sites. conclusion: our results suggest that bd with psychosis is associated with a different pattern of interhemispheric connectivity than bd without psychosis and could be considered a relevant neuroimaging subtype of bd. © 2015 8872147 canada inc.