Parental Stress in Families with 16p11.2 Duplications and Deletions with and without ASD
Extant literature indicates parents of children with autism spectrum disorders (ASD) experience higher levels of parenting stress than parents of children with other disabilities and typically developing children (Dumas, et al., 1991). ASD related deficits in social and behavioral functioning are the factors associated with overall parenting stress (Davis & Carter, 2008). Given the incidence of 16p11.2 duplications and deletions implicated in ASD (Sanders et al., 2011), knowledge related to parental stress in families in this population with copy-number variations (CNVs) and ASD is needed.
The current study aimed to examine parental stress for parents of children 16p11.2 duplications and deletions with and without ASD from the well characterized Simons VIP sample (Simons VIP Consortium, 2012). Additional child phenotypic variables were examined in this population.
Our analysis included parent and child data from probands with 16p11.2 duplications (n = 107) and deletions (n = 113), ages 10 months to 23 years 5 months and their parents. Of the probands examined, 36 had a diagnosis of ASD (assessment using ADOS-2, ADI and DSM-IV criteria). Parental stress was measured by the Parenting Stress Index (PSI; Abidin, 1990) total score. Child factors, including internalizing and externalizing t-scores from the Child Behavior Checklist (CBCL; Achenbach, 1991) and Full Scale IQ Standard Score from the Differential Ability Scale for Children (DAS; Elliot, 1990) were examined.
A 2 (ASD diagnosis, fixed, between groups) x 2 (CNV status, fixed, between groups) factorial ANOVA on parental stress showed a significant effect of ASD on parental stress, F(1,213) = 7.416, p = .007, η2 = .033. There was no main effect of CNV status and no significant interaction between CNV status and ASD, indicating significantly higher levels of stress in parents with children diagnosed with ASD regardless of CNV type (see Figure 1). In children with ASD and 16p11.2 deletions there was strong positive correlations between externalizing behaviors and parental stress, r = .61, n = 23, p = .003; internalizing behaviors and parental stress r = .49, n = 23, p = .018; and no correlation between IQ and parental stress. No significant correlations were found in children with ASD-16p11.2 duplications. See Table 1 for correlations.
Results indicate significantly elevated stress in parents with children ASD regardless of 16p11.2 duplication/deletion status. This suggests, that even when strongly controlling for etiological factors within a biologically defined group, it is ASD-associated behaviors and symptoms that are playing a strong role in parental stress. We further examined variables that have been previously associated with parental stress in the ASD population. These correlations revealed significant associations of parental stress in the ASD-deletion group and non-ASD-deletion/duplication groups with externalizing and internalizing behavior. Small sample size is likely driving the nonsignificant correlations of the ASD-duplication group (n=12), as it appears that many factors contribute to the complexity of parental stress in this population. Future research should examine parent-child traits that serve to precipitate, perpetuate and protect parental stress in this unique population affected by 16p11.2 CNVs.