Regression in Children with ASD: Associations with Parents' Beliefs about Causes of ASD
Objectives: (a) To provide descriptive information about regression status across three related samples; (b) To assess parents' degree-of-agreement with various potential causes of ASD; and (c) To determine whether child history of regression is associated with beliefs about causes of ASD.
Methods: Data were analyzed for children with ASD (probands; N=2758; M age=9 years, SD=3.6 years, range=4—17.9 years) who participated in the Simons Simplex Collection (SSC). Regression was defined according to the Autism Diagnostic Interview—Revised (ADI-R), with rates of language and social-skill losses calculated for the full SSC sample; SSC probands from the Baylor College of Medicine (BCM) site (n=203); and a subset of BCM probands who were recontacted for additional data collection (n=68), including parents' beliefs about causes of ASD via the Revised Illness Perception Questionnaire (IPQ-R; Moss-Morris, et al., 2002). Frequencies of agreement/disagreement with possible ASD etiologies were calculated for the IPQ-R's 21 closed-ended items about potential causes. Qualitative analyses were used to categorize parents’ open-ended rankings of their top three beliefs about causes of ASD. ANOVA’s were conducted to determine whether parents’ degree-of-agreement with various etiologies differed according to their child’s regression status.
Results: Regression rates were only slightly higher in the BCM samples: full SSC=29.5%, full BCM=34%, recontacted BCM=35.3%. The five causes that families most frequently endorsed were genetics (75.8%), child’s brain structure (59.7%), will of God (46.3%), toxins found in vaccines (41.8%), and environmental pollution (37.4%). Parent-provided causes were organized into 10 categories, with genetics/heredity being first-ranked among the largest proportion of parents (42.6%); however, external factors were ranked (i.e., 1st, 2nd, or 3rd) by nearly 84% of families as causing ASD. Parents who reported regression in their children were more likely to agree with “toxins in vaccines” (F[1,66]=3.74, p=.05) and “environmental pollution” (F[1,66]=3.25, p=.07) as causes.
Conclusions: Findings support an association between parent-reported regression in children with ASD and parental endorsement of vaccines/external mechanisms as causing autism, even within this small subsample. That so many also endorsed “will of God” may reflect potential geographical and/or cultural differences within the BCM subsample. Replication of this study at other SSC sites will elucidate varying belief patterns by locale for targeted education efforts.