Premium
Unaffected twins discordant for affective disorders show changes in anterior callosal white matter microstructure
Author(s) -
Macoveanu J.,
Vinberg M.,
Madsen K.,
Kessing L. V.,
Siebner H. R.,
Baaré W.
Publication year - 2016
Publication title -
acta psychiatrica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.849
H-Index - 146
eISSN - 1600-0447
pISSN - 0001-690X
DOI - 10.1111/acps.12638
Subject(s) - corpus callosum , fractional anisotropy , white matter , psychology , cingulum (brain) , diffusion mri , uncinate fasciculus , major depressive disorder , mood disorders , neuroscience , psychiatry , medicine , magnetic resonance imaging , mood , anxiety , radiology
Objective The neurobiological mechanisms mediating an increased risk to develop affective disorders remain poorly understood. In a group of individuals with a family history of major depressive ( MDD ) or bipolar disorder ( BD ), we investigated the microstructural properties of white matter fiber tracts, that is, cingulum bundle, uncinate fasciculus, anterior limb of the internal capsule, and corpus callosum, that facilitate the communication between brain regions implicated in affective disorders. Method Eighty‐nine healthy mono‐ or dizygotic twins with a co‐twin diagnosed with MDD or BD (high‐risk) and 57 healthy twins with a co‐twin with no familial history of affective disorders (low‐risk) were included in a diffusion tensor imaging study. Result The high‐risk group showed decreased fractional anisotropy ( FA ), a measure of water diffusion directionality, and increased radial diffusivity in the anterior region of corpus callosum compared to the low‐risk group. This abnormality was not associated with zygosity or type of depressive disorder of co‐twin. Conclusion The observed decreased anterior callosal fiber FA in the high‐risk group may be indicative of a compromised interhemispheric communication between left and right frontal regions critically involved in mood regulation. Reduced anterior callosal FA may act as a vulnerability marker for affective disorders in individuals at familial risk.