The Variability of Restricted Repetitive Behavior in Neurodevelopmental and Neuropsychiatric Disorders

Thursday, May 12, 2016: 2:09 PM
Room 307 (Baltimore Convention Center)
D. W. Evans, Geisinger Health System, Lewisburg, PA

Restricted, repetitive behavior (RRB) appears in a wide variety of neurodevelopmental and neuropsychiatric disorders including intellectual disability (ID), autism spectrum disorders (ASD), obsessive-compulsive disorder (OCD), Tourette syndrome (TS) and schizophrenia (Sz), among others. Within each diagnosis there is substantial individual variability in the severity of RRB; the source of this variability has been the subject of considerable debate. Our recent work on genetic copy number variation syndromes (CNVs) indicates that probands’ phenotypic variability on a range of quantitative traits is influenced by family background factors. Thus the degree of impairment exhibited by patients/probands may be influenced by the performance of non-carrier/non-patient family relatives.

Objectives:  This study aims to explore sources of variability of RRBs across neurodevelopmental and neuropsychiatric disorders. We examine parental RRB as a contributing factor explaining the  variability of  children’s RRB in a range of disorders.

Methods:  Three thousand twenty-nine families with at least one child ranging in age from 1 to 18 years of age participated in an online assessment of RRB. These families were recruited through Scientific Sampling International, and were demographically representative of the general U.S. population in terms of race/ethnicity, geographic region, income, and mental health status. Seven hundred forty seven of these children had been diagnosed with at least one neurodevelopmental/neuropsychiatric disorder, including developmental delay, developmental coordination disorder, intellectual disability, ASD, specific language impairment, OCD, TS, depression, anxiety, bi-polar disorder, and schizophrenia. Parents completed the Childhood Routines Inventory-Revised (CRI-R) a 63-item parent report measure of repetitive behavior and restricted interests. Parents also self-reported on the newly developed Adult Routines Inventory (ARI).


Factor analysis revealed a two-factor solution for both the CRI-R and the ARI: Motor Behavior and Compulsions (MBC) and Restricted Interests/Insistence on Sameness (RIS). Next we created “clusters” based on children’s diagnoses. These included: ADHD, depression/anxiety, developmental delay/intellectual disability, ASD, conduct disorder/oppositional defiant disorder, obsessive-compulsive disorder/Tourette syndrome, bi-polar/schizophrenia. Analysis of Variance compared the total CRI-R, MBC and RIS t-scores between the diagnostic cluster groups. The groups differed significantly for total CRI-R (F(8,2852)= 59.24); MBC (F(8,2852)=41.20) and RIS (F(8,2852)=59.86 (all p< 0.00001). Post hoc tests revealed that the ASD and OCD/TS groups had higher total CRI-R scores and for MBC than all other diagnostic groups. For the RIS factor, bi-polar/schizophrenia and OCD/TS were higher than all other groups, with ASD similar to all other diagnostic groups (and greater than children with no diagnosis). Further analyses revealed that a) parent- child intraclass correlations on all scales of the ARI and CRI-R were significant; b) the parents of children with a diagnosis had elevated ARI scores – even when the parents themselves had no history of a clinical diagnosis. 


The findings reported here provide further clarification of the nature of RRB across a variety of neurodevelopmental and neuropsychiatric disorders. We discuss the relevance of these findings for quantitative approaches to clinical assessment and diagnosis. We also discuss the importance of considering family background when determining clinical morbidity, particularly in studies of genomic copy number variation syndromes.