White-matter microstructure and gray-matter volumes in adolescents with subthreshold bipolar symptoms

Abstract

Abnormalities in white-matter (WM) microstructure, as lower fractional anisotropy (FA), have been reported in adolescent-onset bipolar disorder and in youth at familial risk for bipolarity. We sought to determine whether healthy adolescents with subthreshold bipolar symptoms (SBP) would have early WM microstructural alterations and whether those alterations would be associated with differences in gray-matter (GM) volumes. Forty-two adolescents with three core manic symptoms and no psychiatric diagnosis, and 126 adolescents matched by age and sex, with no psychiatric diagnosis or symptoms, were identified after screening the IMAGEN database of 2223 young adolescents recruited from the general population. After image quality control, voxel-wise statistics were performed on the diffusion parameters using tract-based spatial statistics in 25 SBP adolescents and 77 controls, and on GM and WM images using voxel-based morphometry in 30 SBP adolescents and 106 controls. As compared with healthy controls, adolescents with SBP displayed lower FA values in a number of WM tracts, particularly in the corpus callosum, cingulum, bilateral superior and inferior longitudinal fasciculi, uncinate fasciculi and corticospinal tracts. Radial diffusivity was mainly higher in posterior parts of bilateral superior and inferior longitudinal fasciculi, inferior fronto-occipital fasciculi and right cingulum. As compared with controls, SBP adolescents had lower GM volume in the left anterior cingulate region. This is the first study to investigate WM microstructure and GM morphometric variations in adolescents with SBP. The widespread FA alterations in association and projection tracts, associated with GM changes in regions involved in mood disorders, suggest altered structural connectivity in those adolescents.

Brain network analysis reveals affected connectome structure in bipolar I disorder

“…The etiology of affected interhemispheric connectivity in bipolar disorder remains to be determined. Studies in adolescents with overt bipolar disorder [Barnea‐Goraly et al, ] or sub‐threshold bipolar symptoms [Paillère Martinot et al, ] have reported similar connectivity changes in these individuals. Furthermore, healthy children with a parent with bipolar disorder have been shown to display a linear decrease in CC FA with age, contrasting an increase in CC FA with age in adolescent controls [Versace et al, ].…”

White matter microstructural abnormalities in families multiply affected with bipolar I disorder: a diffusion tensor tractography study

“…Reports of increases in RD are a recurrent finding in BD studies, notably in euthymic or younger adolescent and adult patient cohorts (Benedetti et al 2011b;Ambrosi et al 2013;Emsell et al 2013b;Lagopoulos et al 2013;Paillere Martinot et al 2013;Versace et al 2013). Reports of increases in RD are a recurrent finding in BD studies, notably in euthymic or younger adolescent and adult patient cohorts (Benedetti et al 2011b;Ambrosi et al 2013;Emsell et al 2013b;Lagopoulos et al 2013;Paillere Martinot et al 2013;Versace et al 2013).…”

FKBP5 Genotype and Structural Integrity of the Posterior Cingulum

“…In particular, structural abnormalities in posterior aspects of the cingulum (PC), assayed with DTI, may promote emotional disturbance; these abnormalities have been highlighted in DTI studies of psychiatric disorders, including schizophrenia (Chen et al, 2013;Fujiwara et al, 2007), anorexia (Kazlouski et al, 2011), depression (Schermuly et al, 2010), bipolar disorder (Paillere Martinot et al, 2013), and post-traumatic stress disorder (PTSD; Fani et al, 2012). Abnormalities in PC integrity have also been identified in traumatized populations, including individuals who experienced childhood abuse (Choi et al, 2009), natural disasters (Wang et al, 2010), and interpersonal trauma (Fani et al, 2012).…”