‘Mothering from the inside out’ (MIO): protocol for a randomized trial of a parenting intervention in substance use disorder treatment

The stress of parenting during recovery can lead to harm for mothers with substance use disorders (SUDs) and their children. “Mothering from the Inside Out” (MIO) is an evidence-based intervention for mothers in SUD treatment that targets parental reflective functioning, the capacity to identify and regulate emotions during stressful parenting situations and address the child’s attachment needs. Although MIO is efficacious when delivered by expert clinicians, challenges remain in its implementation in ‘real world’ treatment programs by SUD and mental health counselors. A type II hybrid effectiveness-implementation randomized clinical trial will recruit mothers and counselors from two SUD treatment and behavioral health agencies in Massachusetts. Participating mothers will be 200 women aged 18 years or older with SUD who are caring for a child aged 5 years or younger as guardian or with regular contact working towards reunification. Mothers will be randomized 2:1 to twelve (12) weekly, 45-60-minute individual MIO sessions plus treatment-as-usual (TAU) SUD services (MIO + TAU) or TAU alone. The 16 counselors trained to deliver the intervention will be 21 years or older, employed by a participating agency, and hold a bachelor’s degree or greater in a counseling discipline. All participating counselors will have demonstrated adequate fidelity, therapeutic alliance, and clinical reflective functioning on standardized assessments. These MIO Counselors will receive regular supervision from their agency and MIO Trainers. Primary effectiveness outcomes will examine the mothers’ end-of-intervention parental reflective functioning, parenting stress, and substance use. An adaptation of the Implementation Research Logic Model will guide the implementation evaluation using a mixed methods approach to identifying implementation process differences at the site level. Overall implementation integrity will be assessed. Primary implementation outcomes will include counselors’ fidelity to core components on the MIO Treatment Fidelity Scales – Revised (MIO-TFS-R) and MIO Fidelity Checklist, and feasibility measured as delivering MIO at the desired treatment intensity. Finally, we will assess contextual determinants (site, counselor, mother characteristics) of effectiveness and implementation outcomes. This study will inform progress towards bringing MIO to scale while maintaining treatment integrity and ensuring continued methodological rigor aimed at optimizing parenting outcomes under real-world conditions. ClinicalTrials.gov Identifier: NCT07168642, Registration date: August 13, 2025.