Gray matter volume in adolescent anxiety: an impact of the brain-derived neurotrophic factor Val(66)Met polymorphism?
OBJECTIVE
Minimal research links anxiety disorders in adolescents to regional gray matter volume (GMV) abnormalities and their modulation by genetic factors. Prior research suggests that a brain-derived neurotrophic factor (BNDF) Val(66)Met polymorphism may modulate such brain morphometry profiles.


METHODS
Using voxel-based morphometry and magnetic resonance imaging, associations of BDNF and clinical anxiety with regional GMVs of anterior cingulate cortex, insula, amygdala, and hippocampus were examined in 39 affected (17 Met allele carriers, 22 Val/Val homozygotes) and 63 nonaffected adolescents (27 [corrected] Met allele carriers, 36 [corrected] Val/Val homozygotes).


RESULTS
Amygdala and anterior hippocampal GMVs were significantly smaller in patients than in healthy comparison adolescents, with a reverse pattern for the insula. Post-hoc regression analyses indicated a specific contribution of social phobia to the GMV reductions in the amygdala and hippocampus. In addition, insula and dorsal-anterior cingulate cortex (ACC) GMVs were modulated by BDNF genotype. In both regions, and GMVs were larger in the Val/Val homozygote patients than in individuals carrying the Met allele.


CONCLUSIONS
These results implicate reduced GMV in the amygdala and hippocampus in pediatric anxiety, particularly social phobia. In addition, the data suggest that genetic factors may modulate differences in the insula and dorsal ACC.
Development and Affective Neuroscience, National Institute of Mental Health (NIMH), University of Ghent, Belgium. Sven.Mueller@UGent.be
Sven C
SC
Mueller
Aveline
A
Aouidad
Elena
E
Gorodetsky
David
D
Goldman
Daniel S
DS
Pine
Monique
M
Ernst
D000293:Adolescent; D000294:Adolescent Behavior; D019943:Amino Acid Substitution; D001008:Anxiety Disorders / Q000235:genetics / Q000473:pathology; D001921:Brain / Q000473:pathology*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods; D020022:Genetic Predisposition to Disease; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008715:Methionine / Q000235:genetics; D009929:Organ Size; D020641:Polymorphism, Single Nucleotide; D011569:Psychiatric Status Rating Scales; D014633:Valine / Q000235:genetics
D019208:Brain-Derived Neurotrophic Factor; D008715:Methionine; D014633:Valine