title: The progression of severe behavior disorder in young children with intellectual and developmental disabilities.
abstract: Behavior disorders, such as self-injurious, stereotypic, and aggressive behavior are common among individuals with intellectual or developmental disabilities. While we have learned much about those behaviors over the past few decades, longitudinal research that looks at developmental trajectory has been rare. This study was designed to examine the trajectory of these three forms of severe behavior disorders over a one year time period. The behaviors were measured on two dimensions: frequency of occurrence and severity. Participants were 160 infants and toddlers at risk for developmental delays in Lima, Peru. Using structural equation modeling, we found that the frequency of self-injury and stereotypic behavior and the severity of aggressive behavior remained stable over the 12-month period. Uni-directional structural models fit the data best for self-injurious and aggressive behavior (with frequency being a leading indicator of future severity of self-injury and severity being a leading indicator of future frequency for aggression). For stereotypic behavior, a cross-lagged autoregressive model fit the data best, with both dimensions of frequency and severity involved as leading indicators of each other. These models did not vary significantly across diagnostic groups, suggesting that toddlers exhibiting behavior disorders may be assisted with interventions that target the specific frequencies or severities of behaviors, regardless of diagnostic category.
authors.affiliation: Applied Developmental Psychology, George Mason University, Fairfax, VA 22030, United States. Electronic address: kmedeiro@gmu.edu.
authors.forename: Kristen
authors.initials: K
authors.lastname: Medeiros
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Curby
authors.forename: Alec
authors.initials: A
authors.lastname: Bernstein
authors.forename: Johannes
authors.initials: J
authors.lastname: Rojahn
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Schroeder
mesh_terms: D000374:Aggression / Q000502:physiology*; D002653:Child Behavior Disorders / Q000150:complications / Q000503:physiopathology; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000503:physiopathology*; D002675:Child, Preschool; D015331:Cohort Studies; D002658:Developmental Disabilities / Q000150:complications / Q000503:physiopathology*; D018450:Disease Progression; D004314:Down Syndrome / Q000150:complications / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000150:complications / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D015233:Models, Statistical; D012044:Regression Analysis; D012306:Risk; D016728:Self-Injurious Behavior / Q000150:complications / Q000503:physiopathology*; D012720:Severity of Illness Index; D013239:Stereotyped Behavior / Q000502:physiology*; D019956:Stereotypic Movement Disorder / Q000150:complications / Q000503:physiopathology
keywords: Aggression; Autism spectrum disorder; Behavior disorders; Challenging behaviors; Developmental disability; Down syndrome; Intellectual disability; Self-injury; Stereotypy; Structural equation modeling