Preserved white matter in unmedicated pediatric bipolar disorder

White matter (WM) abnormalities have been reported in bipolar disorder (BD) patients, as well as in their non-BD relatives, both children and adults. Although it is considered an emerging vulnerability marker for BD, there are no studies investigating WM alterations in pediatric unmedicated patients and young healthy offspring. in this study, we evaluated the presence of WM alterations in 18 pediatric, non medicated BD patients, as well as in 18 healthy offspring of BD type I parents and 20 healthy controls. 3T DT-MRI data were acquired and scans were processed with tract-based spatial statistics to provide measures of fractional anisotropy and diffusivity. We found no significant differences in WM microstructure between BD patients, healthy offspring and healthy controls. Previous studies that reported WM alterations investigated older subjects, either on medication (BD patients) or with psychiatric diagnoses other than BD (unaffected offspring). Our findings highlight the importance of the understanding of disease ontogeny and brain development dynamics in the search for early vulnerability markers for psychiatric disorders. (C) 2014 Elsevier Ireland Ltd. All rights reserved.Univ São Paulo, Sch Med, Dept Psychiat, Bipolar Res Program, São Paulo, BrazilUniv São Paulo, Sch Med, Dept Psychiat, Lab Psychiat Neuroimaging, São Paulo, BrazilUniv São Paulo, Ctr Support Res Appl Neurosci, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Psychiat, Child & Adolescent Psychiat Unit UPIA, São Paulo, BrazilFed Univ São Paulo UNIFESP, Dept Psychiat, Child & Adolescent Psychiat Unit UPIA, São Paulo, BrazilWeb of Scienc