Pilot Hybrid Effectiveness-Implementation Trial of a Scalable Intervention Targeting Postpartum Intrusive Thoughts - Project Summary/Abstract Despite their impact, postpartum intrusive thoughts -- unwanted, distressing thoughts, images, and urges often about harming one’s infant -- are common yet overlooked. This can lead to distress, shame, impairment, and for some, diagnoses of depression, anxiety, or OCD; postpartum OCD affects up to 11% of mothers, and postpartum anxiety up to 18%. These diagnoses often arise from interpretation bias - the misinterpretation of one’s intrusive thoughts as dangerous, unacceptable, or predictive of harm. Postpartum mental health referrals, typically at the six-week obstetric appointment, are often ineffective since many miss this visit, non-birthing parents are left out, referral options are scarce, and by this point, most parents with intrusive thoughts have been struggling for weeks, missing a key intervention window. Even when symptoms are identified, parents face treatment barriers including time constraints, lack of childcare, and stigma. Psychoeducation has shown promise for perinatal populations and has potential for targeting interpretation bias by reducing threatening misinterpretations of the thoughts through normalization, increasing disclosure, and reducing shame. Digital Single Session Interventions (SSIs) provide an innovative dissemination strategy; they are self-guided programs delivered in one encounter. There is a critical need for scalable, sustainable interventions that target cognitive vulnerabilities driving postpartum intrusive thoughts. Interventions developed by the study team are compelling but require adaptation to optimize scalability, sustainability, and relevance for new parents at risk. We propose a type 1 hybrid effectiveness-implementation trial to adapt and test an SSI targeting misinterpretation of postpartum intrusive thoughts, and to explore implementation and sustainability. Our central hypothesis is the SSI will reduce interpretation bias and improve outcomes for clinically significant postpartum intrusive thoughts, parent anxiety, parent-infant relationships, and psychosocial functioning. We will also assess preliminary implementation outcomes (e.g., reach, acceptability) to inform long-term sustainability. First, we will develop a personalized digital SSI by adapting existing evidence-based interventions to address postpartum interpretation bias, in collaboration with an Advisory Board of patients and expert clinicians. We will then test this SSI in an open trial with an iterative case series design (N = 24) for new parents with distressing intrusive thoughts, evaluating feasibility and acceptability with continuous refinement. Second, we will conduct a pilot RCT (target N = 80) for a preliminary effectiveness test comparing the SSI vs. waitlist in reducing intrusive thoughts severity. Third, we will explore key implementation outcomes to inform sustainability, interviewing stakeholders and collecting surveys from users to identify barriers and facilitators to sustainable implementation across the digital resources that will deliver this SSI to new parents. Achievement of these aims will support a future fully-powered hybrid type 1 trial. This multidisciplinary team led by an Early Stage Investigator will deliver a brief, sustainable intervention to improve public health for new parents.
