Adolescent Autism Traits: Associations with Parental Age and Physiological Functioning

Background: Both older maternal and paternal age, have been identified as risk factors for having a child with autism (Grether et al., 2009). Little is known regarding the links between parental age and autism severity. Furthermore, atypical cardiac activity has been uncovered among adolescents with ASD (Van Hecke, et al. 2009), suggesting physiological dysregulation (Guy et al., 2014). Thus, autism severity may be associated with physiological arousal and parental age might have implications for both.

Objectives: 1) Explore relations between caregiver-report of autism traits and parental age among a sample of adolescents with ASD. 2) Examine associations between caregiver-report autism traits and physiological arousal measured using heart rate. 3) Determine if HP mediates the link between parental age and caregiver-report of autism traits. Our hypotheses are that positive associations will be uncovered for our first objective, whilst negative associations will be found in our second objective. Finally, HP will mediate the link between parental age and autism traits.

Methods: 167 adolescents with ASD aged 11-16 and their parents/caregivers participated in this study. Participants presented for a RCT of a social skills intervention; data here is from pretest. Descriptive statistics are in Table 1. Caregivers completed a demographic form that asked about maternal and paternal age. Presence of autism was confirmed with the ADOS, IQ was measured with the KBIT-2. All participants had an IQ ≥ 70. Caregivers also completed the Autism Quotient (AQ) and Social Responsiveness Scale (SRS) as measures of autism traits, which were analyzed at a subscale and total score level. Higher scores on these measures indicated greater autism severity. Heart period (HP) data were collected from a sub-sample (n = 94).

Results: Negative links were uncovered between maternal age and the AQ Communication (r(167) = -.157, p = .043) and SRS Cognition subscales (r(167) = -.187, p = .016). Considering paternal age, negative relations were found for the AQ Communication (r(160) = -.192, p = .015), SRS Cognition (r(160) = -.223, p = .005), SRS Autistic Mannerisms subscales (r(160) = -.179, p = .023), and SRS Total (r(160) = -.194, p = .014). Associations between HP and the SRS Cognition (r(93) = -.206, p = .046), Autistic Mannerisms (r(93) = -.224, p = .030), and Total (r(93) = -.315, p = .002) were found. No significant mediation was uncovered.

Conclusions: The negative links uncovered between parental age and autism severity suggest that milder symptoms are found in children of older parents. This may indicate that, in addition to established associations with risk for having a child with autism, parental age may also be associated with the severity of autism symptoms. Because older parental age was associated with less severe scores on the SRS, future studies might explore other factors related to parental age (such as parenting style) as these may impact the severity of autism symptoms in their children (Mohammadi & Zarafshan, 2014). Furthermore, a negative link was discovered between autism severity and physiological arousal, thus, more physiological dysregulation seems to be related to greater autism severity.