Digital interventions have the potential to support healthier behaviors among pregnant and postpartum women (PPW) with substance use disorders (SUDs) and may also provide a promising method for reducing their self-stigma. Enhearten is a digital intervention designed to foster adherence to medications for addiction treatment (MAT) while considering the unique needs of PPW, but its effects on self-stigma, treatment retention, and SUD outcomes have not been rigorously tested. The investigators will conduct an individual-level multicenter randomized controlled trial to test the feasibility, acceptability, and efficacy of Enhearten on reducing self-stigma and on improving SUD treatment and recovery outcomes with a stigma-focused ecological momentary intervention (EMI) designed to: 1) screen for feelings of stigma and 2) counteract these vulnerabilities among PPW with SUD via just-in-time interventions.

Pregnant and postpartum women (PPW) with substance use disorders (SUDs) face high levels of self-stigma, the internalization of negative feelings about oneself because of drug misuse. Self-stigma is highly correlated with numerous detrimental consequences including recovery outcomes and reduced engagement with SUD treatment. Furthermore, self-stigma prevents treatment initiation and engagement among PPW with SUDs, leading to additional adverse health outcomes for both mother and baby. Digital interventions have the potential to support healthier behaviors among PPW with SUDs and may also provide a promising method for reducing their self-stigma. Enhearten is a digital intervention that has been enhanced to foster adherence to medications for addiction treatment (MAT) while considering the unique needs of PPW, but its effects on self-stigma, treatment retention, and SUD outcomes have not been rigorously tested. In this study, the investigators will test this augmented version of Enhearten with a stigma-focused ecological momentary intervention (EMI) designed to: 1) screen for feelings of stigma and 2) counteract these vulnerabilities via just-in-time interventions. Specifically, the investigators will conduct an individual-level multi-center randomized control trial (RCT) to test the feasibility, acceptability, and efficacy of Enhearten on reducing self-stigma and on improving SUD treatment and recovery outcomes. Participants will be randomized to one of two groups: Enhearten with EMI or a waitlist control group (i.e., participants will have access to the intervention following the RCT). Recruitment will occur through treatment facilities and recovery homes throughout the United States, referrals from stakeholders including clinicians and peer support specialists, and approved research recruitment registries. This study will determine the efficacy and utility of Enhearten among PPW with SUDs, addressing a promising solution to supplement traditional in-person care, reduce self-stigma, and support continued motivation and adherence to treatment plans along the recovery journey.

Inclusion Criteria:

• Pregnant women and new mothers (up to 12 months postpartum)
• Adult (≥18 years of age)
• Fluent in English
• Currently owns or has ready (daily) access to a smartphone or tablet to use Enhearten.
• Self-reports a history of substance use, excluding alcohol use, nicotine/tobacco use, and drugs taken as prescribed by a physician OR a history of substance use, excluding alcohol use, nicotine/tobacco use, and drugs taken as prescribed by a physician, is identified in chart review as documented by a healthcare provider

Exclusion Criteria:

- Significant cognitive impairment that interferes with their ability to consent and complete study tasks as self-reported or documented in medical charts by a healthcare provider

The university will share de-identified data from the RCT. Descriptions of study datasets, final codebook and data dictionary, and programming code for data management and analysis will also be made available. Data and documentation will be housed at Washington University but will be made freely available to other investigators who wish to conduct data audits or perform secondary data analyses.

The data will be made available 12 months after trial completion after data cleaning and quality control completion.

The research team will make datasets available to any individual who makes a direct request to the MPIs and indicates the data will be used for the purposes of research (per CFR Title 45 Part 46: "Research is defined as a systematic investigation, including research development, testing and evaluation, designed to develop or contribute to generalizable knowledge"). In sharing participant data, the team will follow Office of Sponsored Projects' data sharing agreements at Washington University in St. Louis.