Altered regional gray matter in Congenital Adrenal Hyperplasia (CAH)

Congenital Adrenal Hyperplasia (CAH) has been reported to present with gray matter aberrations, but further research is required as the results of existing studies are inconsistent. These inconsistences might be due to small sample sizes, differences in sample composition (some studies only included females), or the spatial scale of the analyses (some studies focused on selected regions of interest). Here we compiled the largest CAH sample to date comprising 33 women and 20 men matched to 33 control women and 20 control men on sex, age, education, and verbal intelligence. Gray matter was examined with a voxel-wise regional specificity across the entire brain, assessing the main effects of CAH and sex, and the CAH-by-sex interaction (the latter reflecting effects of prenatal androgen exposure). Individuals with CAH had significantly less gray matter compared to controls within the amygdala, calcarine cortex (specifically the primary visual area), and parahippocampal cortex (specifically the subiculum). There also was a main effect of sex, with more gray matter in females than males in medial frontal regions and more gray matter in males than females within the cerebellum. There was no CAH-by-sex interaction. Our findings indicate less regional gray matter in individuals with CAH, which seems to be caused by the medical condition itself and/or its treatment with glucocorticoids, rather than by elevated prenatal androgen exposure.