Research has shown little relationship between adaptive functioning and symptomatology in higher functioning school-aged individuals with ASD, as well as striking deficits in adaptive skills compared to IQ.

Objectives:

The relationship between adaptive functioning (Vineland) and symptomatology (ADOS-G, Modules 1 and 2) is investigated in relation to age and IQ in a longitudinal sample of toddlers at ages 2 and 4.

Methods:

Participants included 101 toddlers with ASD with mean ages of 2.4 years at Time 1 and 4.3 years at Time 2.

Results:

Contrary to older individuals, strong negative relationships were found between Vineland and ADOS Socialization and Communication scores [Communication r (100) = -.40 and Socialization r (100) = -.53 at Time 1, and r (100) = -.51 and r (100) = -.61 at Time 2, respectively], suggesting that toddlers with less severe social and communicative impairments have more advanced adaptive skills. Paired t-tests indicated that, over time, children made significant improvements in adaptive Communication skills (t = 3.26, p<.01), and their Communication (t = 8.24, p<.01) and Social (t = -3.91, p<.01) symptoms as captured by the ADOS-G improved over time. Yet, no significant change in standard scores was noted in the adaptive Socialization skills area (t = .43, p=.67). Despite progress, significant discrepancies were evidenced between mean Mullen and Vineland scores at Time 1 (t = 2.37, p<.01) and Time 2 (t=9.20, p<.01), with this gap widening with age.

Conclusions:

Results suggest that in very young children, level of symptomatology impacts adaptive functioning; however, minimal gains are evident in functional social skills over time regardless of symptom severity. Of further concern, despite progress in both developmental and adaptive skills, the gap between developmental skills and adaptive functioning widens with age, suggesting that the acquisition of functional skills is not keeping pace with developmental gains.