The Attachment and Biobehavioral Catch-up Lab at the University of Delaware has received funding from the National Institutes of Health to study the effectiveness of two home visiting programs for mothers who used/are using substances, including cigarettes, alcohol, marijuana, opioids or Medication Assisted Treatment, during pregnancy. Over the last 28 years, we have been developing, refining, and testing a home visitingmodel, Attachment and Biobehavioral Catch-up (ABC). ABC has now been adapted for parents of infants, parents of toddlers, foster parents, birth parents, and parents adopting internationally. Eligible mothers who enroll are assigned to receive either the ABC parenting intervention oranother home visiting program focused on cognitive and motor development. In addition to 12 parenting sessions, they are invited to come to the University of Delaware to participate in research activities prior to the birth of their child or when their baby is up to 2 months old. Research activities include life history questionnaires, assessments of neural activity, autonomic nervous system regulation, and DNA methylation, among other things. We then do assessments of both mother and infant in the home at 3 months, and at 6 and 12 months at our office. Mothers are compensated for every research visit and parenting session, earning up to $700 over the course of the year if they complete all assessments