as signal attenuated in putamen and concluded that ferritin-bound iron makes an important contribution to DTI metrics in low-signal, isotropic, iron-rich regions. Specifically, it is likely that the apparent increase in FA with age in bilateral putamen may be due to an upward bias in the estimated diffusion anisotropy which is inversely proportional to the loss of MRI signal due to iron deposition. Although iron continues to accumulate throughout the lifespan in healthy cortical and subcortical GM, it occurs over a limited range beyond 30 years of age. Notably, the most gradual accumulation in the basal ganglia occurs in putamen (Rulseh et al., 2013). Therefore, evidence suggests that accumulation of iron deposits in bilateral putamen due to increasing age causes MRI signal attenuation reflected in the apparent increase in FA (Pfefferbaum et al., 2010a). Therefore, our finding of higher FA in bilateral putamen in the AUD group, attributed as an effect of age and not due to group membership or significant changes in AD or RD, tends to confirm this interpretation. We also found a significant lateral asymmetry in putamen apparent FA which, if replicated in independent studies, could indicate higher iron concentration on the left. Additionally, we also found
