Research Summary: National Fragile X Foundation – Translational Research Grant

Len Abbeduto PhD – $75,000

University of Wisconsin – UC Davis M.I.N.D. Institute

SPECIFIC AIMS: The proposed project is designed to gather preliminary data on the efficacy of a parent-mediated language intervention for young, minimally verbal children diagnosed with Fragile X syndrome (FXS). These preliminary data will serve as the basis for an application for a larger evaluation study to be submitted to the NIH. The intervention will entail teaching mothers to use responsive verbal interaction strategies with their affected children during everyday routines and play activities. Maternal verbal responsiveness in naturally occurring interactions has been found to facilitate the development of language not only for typical children, but also for children with developmental disabilities, including FXS. Teaching primary caregivers how to maximize their responsive verbal behaviors has become an important aspect of many early intervention programs. Relative to direct (therapist-provided) service delivery models, involving parents as interventionists leads to increased intensity of treatment and increased opportunities for children to generalize newly acquired skills.

Children with FXS display a number of developmental challenges to language learning, including hyperactivity, social anxiety, and symptoms of autism. Such phenotypic characteristics negatively impact the frequency with which young children with FXS explore the environment, initiate social interactions, and maintain engagement in the types of shared interactions that support the language learning of typically developing children. This highlights the potential importance of teaching mothers how to engage their children in social interaction and provide rich verbal language input at a time and in a manner that allows young children with FXS to process and extract meaning from this input.

The biological mothers of children with FXS also might be particularly good candidates for a parent-mediated intervention. These mothers are at elevated risk for mental health problems (e.g., anxiety and depression) relative to the general population, not only because parenting a child with multiple problems can be stressful, but because they also carry an FMR1 expansion, which may increase vulnerability to stress. In addition, there is evidence that poor maternal mental health can have a negative impact on parent-child interaction and thereby on child language development. In fact, evidence exists that some mothers of children with FXS engage in less than optimal levels of responsive interaction. Such findings suggest that targeting maternal behavior in parent-child interactions may be a particularly powerful method of optimizing language outcomes in children with FXS.

The goal of the proposed project is to evaluate an intervention in which the biological mothers of minimally verbal 2- to 6-year-old children with FXS are taught to engage in responsive, child-centered interactions filled with rich language learning opportunities. Specific intervention targets will include teaching parents to maintain active child engagement, talk about their child’s focus of attention, prompt child communication, and respond to child communication bids with developmentally progressive language. We will use an experimental design in which parent-child dyads are randomly assigned to either a Parent Mediated Intervention (PMI) Condition or an Information Only (IO) Comparison Condition. The PMI condition is designed to change child spoken language outcomes by targeting parent verbal responsiveness, which we hypothesize to be causally related to gains in child language. Participants assigned to the IO comparison condition will receive general information about child challenging behaviors in a didactic format. The goal is to establish the efficacy of PMI relative to treatments typically received by families affected by FXS; thus, the IO condition serves, not as a legitimate alternative treatment, but as a way of maintaining parent motivation to remain in the project without substantially adding to or interfering with the child’s treatment as usual. Note that the PMI and IO procedures provided through this study will be added to existing intervention services that children are receiving.

The PMI will be implemented by a speech-language pathologist and graduate student clinicians and will involve on-site didactic parent education sessions and on-site coaching and modeling during parent-child play sessions. Given the likelihood that most affected families live at a distance from center-based intervention programs, on-site sessions will be supplemented by distance-based video teleconferencing. In addition to reducing the necessity to travel to receive intervention services, distance sessions will increase the intensity of the treatment and foster generalization by enabling mothers to receive real-time feedback as they interact with their children at home. In addition, the PMI will include strategies for addressing child behavior problems that interfere with productive object-focused engagement and reciprocal social interaction.

In summary, the specific aims are: (1) to determine whether PMI results in increases in child language and communication skills; (2) to determine whether PMI results in increases in maternal verbal responsiveness; (3) to provide evidence that changes in maternal verbal responsiveness mediate any effects of the intervention on child outcomes; and (4) to explore in preliminary fashion maternal and child characteristics (maternal mental health, child challenging behaviors, and symptoms of autism) that might influence the efficacy of the intervention.