A Single-Arm Pilot trial for Mitigating Relapse of Severe Problem Behavior - Project Summary/Abstract Over 2 million people in the United States with intellectual and developmental disabilities (IDD) engage in some form of SPB (self-injury, aggression; Crocker et al., 2006). For these individuals, SPB can impair functioning, produce injury, strain healthcare and other service systems, and lead to restrictive placement. Behavior-analytic treatments are the current gold standard for reducing SPB, with functional communication training (FCT) being among the most common behavioral treatments. Such treatments are most effective when implemented by trained staff in highly specialized settings (e.g., inpatient and outpatient clinics). In these settings, treatment is initially implemented with a high level of intensity (e.g., dense schedules of reinforcement for appropriate behavior) and with high treatment fidelity (e.g., reinforcement for appropriate behavior at the prescribed schedule, etc.). Unfortunately, treatment gains obtained in these specialized settings sometimes fail to maintain in the face of treatment challenges, such as when treatment is generalized to new agents or settings, or when alternative reinforcement is reduced. The current proposal focuses primarily on two types of treatment challenges: (a) context changes and (b) decrements in alternative reinforcement, each of which each of which can that produce two common forms of relapse: renewal and resurgence, respectively (Podlesnik & Kelley, 2015). These relapse phenomena may also be compounded when they occur simultaneously (e.g., “super-resurgence”; Kincaid et al., 2015), such as when there is a context change that co-occurs with decrements in reinforcement (e.g., a novel caregiver implements treatment and fails to deliver reinforcement for an appropriate response). As planned and unplanned treatment challenges that can lead to relapse are inevitable, the question is how we can mitigate relapse when they occur. This proposal describes an exploratory single-arm clinical trial to evaluate specific tactics designed to mitigate renewal, resurgence, and super-resurgence of SPB among individuals with IDD. Broadly, these relapse-mitigation tactics include: (a) multiple context training, (b) incorporation of extinction-correlated stimuli, (c) systematic caregiver fading procedures, (d) provision of effective competing stimuli that reduce excessive bidding for functional reinforcers during schedule thinning, and (e) application of probe-based schedule thinning procedures. These tactics have preliminary empirical support but have primarily been examined in isolation, or predominantly evaluated in translational research using analog paradigms. The current proposal combines multiple these relapse- mitigation tactics and evaluates their feasibility and preliminary efficacy for mitigating both renewal and resurgence with individuals with IDD undergoing FCT for SPB. Outcomes will be evaluated using a single-case experimental design with embedded treatment challenges to examine renewal, resurgence and super resurgence (see Haney et al., 2021). In addition to the practical benefits of identifying tactics to mitigate relapse, this work will also advance knowledge on the underpinnings of relapse, which will have both practical and scientific value.