Treatment-seeking status was a significant moderator. Treatment-seeking and non-treatment-seeking samples had significantly different ES, t(16) = 2.839, p = .012. The ES for studies with non-treatment-seeking samples was b (unstandardized) = −.088 (SE = .121), whereas the ES for studies with treatment-seeking samples was positive, b = .433 (SE = .183). In short, the negligible difference between non-treatment-seeking samples and control groups stood in contrast to a medium-sized effect for WM reduction in treatment-seeking samples compared to control groups.
