In conclusion, the present meta-analysis found an ES of .304 for WM volume reduction in AUDs. This effect was robust with regard to potential confounds such as sample size, age, and MRI methodology. Treatment-seeking status and duration of abstinence were significant moderators of the ES distribution, with group differences maximized in treatment-seeking populations and in early abstinence. Because women and non-treatment-seeking individuals have been underrepresented in neuroimaging research in AUDs, conclusions about the effect of AUDs on WM in these populations remain tenuous. Future studies would profit from examining moderators and mediators of the effects of treatment-seeking status and length of abstinence in larger, more representative samples and with methods such as DTI, which is sensitive to changes in WM integrity.
