The Differential Relationship Between Competence and Stress Across Parent Groups for Caregivers of Children with Autism Spectrum Disorder

Background: Parents of children with autism spectrum disorder (ASD) report exceptionally high levels of stress compared to parents of children with other medical or developmental conditions. Stress patterns relate to core symptomatology as well as externalizing behavior (Davis & Carter, 2008), particularly challenging behavior. Although parent training (PT) seems applicable to these concerns, data on the effects of PT on parenting stress are mixed (Strauss, 2012). Because parent characteristics are likely to influence treatment outcomes, parent variables should be evaluated as potential mediators and moderators. One promising variable is parent competence. In the literature on externalizing disorders and challenging behavior in typically developing children, PT results in increased parent competence (de Graaf et al., 2008; Graf, 2014), which is a mediator of improvement in parent and child behavior (Dekovic, 2010; Graf et al., 2012).

Objectives: Evaluate the extent to which change in parent competence relates to change in parent stress and statistically test if this relationship significantly differs between PT and a control condition (psychoeducation; PE). 

Methods: Children with ASD (age 3-7 years) and their families were randomly assigned to parent training (PT; n=89) or to psychoeducation (PE; n=91) for six months. Competence was measured with the Parent Sense of Competence (PSOC), and stress was measured with the Parenting Stress Index (PSI-SF) and Caregiver Strain Questionnaire (CGSQ). The primary child outcome measure was the Aberrant Behavior Checklist – Irritability (ABC-I). Parents completed these rating scales at baseline, week 12, and week 24 (post-treatment). A latent difference score (LDS) approach (McArdle, 2009) was used to examine group differences in initial competence and later stress, as well as whether change in competence predicted change in stress and if this relationship differed across groups.  

Results: At Week 24 (post-treatment), parents in PT showed a significant advantage over parents in PE on the PSOC (ES=.34), CGSQ (ES=.50), and Difficult Child subscale of the PSI-SF (ES=.44), although not PSI-SF total (p=.07; ES=.25). Parents in PT and PE began treatment with comparable levels of competence (p > .05) and significantly increased competence from baseline to week 12 (ps<.01), with parents in PT making greater gains than those in PE (z=1.99, p<.05). Both groups also reduced stress from Week 12 to Week 24 (ps<.05); this amount of change did not significantly differ between PT and PE. Change in competence was not significantly associated with change in stress in either PT or PE. Change in competence predicted favorable change in ABC-I (p<.05), but this relationship did not differ across groups.

Conclusions: The differentially greater increase in competence at week 12 in PT (versus PE) did not confer incremental benefit in terms of decreased stress post-treatment. This suggests that while further exploration of competence in this population is warranted, other potential parent variables that may impact treatment outcomes for children with ASD should be explored.