It is likely that reduction in problem behavior is both, in part, a cause and an effect of improvement in parental affect. The average weighted effect size for reductions in depressive symptoms was d 5 0.25, which approaches the 0.26 effect size derived from nine studies that measured depressive symptoms in a recent Barlow et al. [2003] meta-analysis of the collateral benefits of several theoretical approaches to parent training for parents of children without disabilities. We believe that there is sufficient evidence to warrant the claim that these treatments are evidence-based as ways to help parents with stress-related distress, particularly depressive symptoms, at least for the short term for middle class White American mothers. The evidence suggests that BPT may not only change parenting behavior, but also it has small but consistent collateral benefits.