Understanding the Landscape of Behavioral Interventions for Individuals with Phelan-Mcdermid Syndrome

Background: The essence of developmental synaptopathies (DS) such as Phelan-McDermid Syndrome (PMS), PTEN, and Tuberous Sclerosis Complex (TSC) suggest a need for interventions addressing nontraditional treatment targets – namely learning and cognition. The presence of cognitive and physical delays in DS suggests an increased risk for failing to respond to behavioral intervention as a stand-alone treatment, in part due to impairments in learning, motivational, and motor abilities. Developing effective interventions for DS requires paradigms with potential to address complex processes like learning, as well as procedures for enhancing generalization and maintenance of new skills. Any novel behavioral intervention used with this population must be acceptable, compatible, and feasible at a minimum to ensure effectiveness and sustainability. Particularly important is parents’ perception that proposed intervention approaches are reasonable, appropriate and relevant for the unique needs of their children.

Objectives: The ultimate aim of this program of work is to identify an acceptable, effective, and safe therapeutic approach to enhance learning processes leading to sustainable improvements in individuals with DS. As a first step in this process, we examined the landscape of behavioral interventions for individuals with Phelan-McDermid Syndrome (PMS) by developing a better understanding of the acceptability of existing behavioral interventions and identifying barriers that may limit the impact and sustainability of these interventions.

Methods: This study used a research-community partnership framework, which emphasizes collaboration with community stakeholders to address a variety of shared goals. An online survey for parents of individuals with PMS was developed to gather quantitative and qualitative about perceptions of and experiences with behavioral interventions. Participants were asked about the nature and acceptability of prior experiences with behavioral intervention. They were also asked to suggest modifications to improve the fit of these programs with the unique needs of their child and family. Descriptive statistics were used to analyze the survey data.

Results: Applied Behavior Analysis (ABA) was the most commonly endorsed behavioral intervention, followed by developmental interventions, and naturalistic developmental behavioral interventions (NDBIs). Parents rated early social communication skills (e.g., turn taking) and expressive language as the most important intervention targets, indicated the importance of delivering behavioral intervention across settings (e.g., home and school), and expressed a desire for a stronger parent/caregiver training component to these services. Suggested modifications to existing models include more flexibility in terms of scheduling appointments and better training for clinicians around the PMS profile and appropriate intervention targets for this population.

Conclusions: There was a wide range of variability in terms of the nature, intensity and acceptability of interventions received by individuals with PMS in the community. Importantly, parents reported many limitations that are consistent with those reported in previous studies of individuals with neurodevelopmental disabilities, including some that appear more PMS-specific. Data from this survey study will be used to inform the next phase of this work seeking to develop and investigate a novel multi-modal therapy utilizing a high quality behavioral intervention plus targeted pharmacotherapy to improve early social learning and communication in individuals with PMS.