This is a new Stage III community-based randomized clinical efficacy trial testing Mothering from the Inside Out (MIO), the first evidence-based parenting intervention designed to be delivered by addiction counselors in addiction treatment settings where parents of young children are enrolled in treatment. MIO is a weekly individual parenting therapy developed as an enhancement to standard addiction treatment that targets the addicted mother's capacity to recognize and regulate her own emotional distress during stressful parenting situations so that she can support her child's developing capacity for emotional and behavioral regulation. This capacity, called reflective functioning (RF), is a psychological skill that promotes abstinence and also helps parents foster their young children's secure attachment. Now that MIO has demonstrated efficacy in two randomized efficacy trials, the next step will be to conduct a new Stage III community-based efficacy trial where addiction counselors are trained to deliver MIO and PE with fidelity in an addiction treatment setting and to evaluate treatment outcomes and mechanisms of change in this community setting. At the end of this trial, if MIO demonstrates efficacy, all the necessary materials will be ready to train addiction counselors across a broad range of treatment settings in a Stage IV effectiveness trial. 120 mothers in addiction treatment and caring for children ages 11 - 60 months will be randomized to 12 sessions of MIO vs PE with a trained addiction counselor and fidelity will be monitored and maintained for treatment duration. It is expected that MIO-assigned mothers will demonstrate greater improvement in the primary targeted outcome - reflective functioning at week 12 (end of treatment) and week 33 (end of follow up). It is also predicted that MIO-assigned mothers will demonstrate greater improvement in secondary outcomes, including maternal sensitivity, caregiving behavior, psychiatric distress, depression and substance use at week 12 (end of treatment) and week 33 (end of follow up). Finally, it is predicted that children of MIO-assigned mothers will demonstrate greater improvement in the secondary outcome - attachment security - at week 12 (end of treatment) and week 33 (end of follow up).