In addition to alteration in regions associated with social cognition, the female HR subjects showed reduced volume of the left crus I and left lobe 8 of the cerebellum. This finding of reduced volume of these cerebellar regions would appear to be at odds with our previous reports of larger cerebellar volume that appears to be associated with inefficient pruning among high-risk offspring (Hill et al., 2007; 2011, 2015). The difference in findings can be explained on the basis of differences in sample selection. These previous reports concerned multiplex families ascertained through pairs of male alcohol dependent probands. Mothers of offspring from that study typically were not large consumers of alcohol during pregnancy (Hill et al., 2009) in contrast to offspring from this study of multiplex families ascertained through pairs of female alcohol dependent probands who show much higher levels of alcohol consumption during pregnancy. Due to the high collinearity between risk for AD and use of alcohol during pregnancy, we may not have been able to completely separate the effects of familial risk and higher levels of alcohol consumption in the present sample resulting in the observed reduction of cerebellar volume in this study.
