Adaptive Behavior and Executive Functioning in Children with Neurofibromatosis Type 1 Using a Mixed Design

Objective: Children with neurofibromatosis type 1 (NF1) demonstrate poorer adaptive functioning compared with same-aged peers; however, there is limited research about the longitudinal pattern of adaptive behavior. The aim of this investigation was to examine parent-reported adaptive behavior of children with NF1 longitudinally beginning in early childhood and to examine relations with executive functioning. Method: Children with NF1 were assessed during early childhood (n = 59; aged 3-7; mean = 4.8, SD = 1.42) or school age (n = 39; aged 9-13; mean = 10.85, SD = 1.58), and a subset was seen at both time points (n = 26). The Scales of Independent Behavior-Revised was used to assess adaptive functioning, and the Behavior Rating Inventory of Executive Function-Preschool Version/Behavior Rating Inventory of Executive Function was used to evaluate everyday executive functioning. Results: Adaptive behavior in early childhood was significantly correlated with adaptive behavior at school age (with the exception of social interaction and communication skills) and was significantly poorer at school age. The frequency of difficulties increased over time for overall adaptive behavior and motor skills. Executive functioning was related to adaptive behavior cross-sectionally within early childhood and at school age and showed longitudinal predictive value over time. Conclusion: This research contributes to the limited NF1 adaptive behavior literature by characterizing the longitudinal pattern of adaptive behavior and relations with executive abilities.