Short and Longer Term Outcomes for Toddlers with ASD Enrolled in Early Intervention

Background: Very early intervention for autism has the potential to optimize outcomes and perhaps even prevent a cascade of increasing separation from peers with typical development with regard to the development of social and communication functioning.  Data from studies of preschoolers are beginning to show promise that even core deficits of autism may be ameliorated by targeting deficits such as joint attention in intervention.  The study described herein is one of the largest intervention studies to date involving 2-year-olds with autism spectrum disorders (ASD); the data reveal insights into the important effects of early intervention.
Objectives: To determine whether core deficits of ASD could be ameliorated through targeting such deficits in early in life.
To examine the longer-term outcomes of 2-year-olds enrolled in intervention that targeted social communication and language development.
Methods: Forty-nine toddlers with ASD (23-33 months of age at enrollment) participated in a 6-month nursery school-based comprehensive early intervention for 10 hours per week. Children were matched on verbal and non-verbal mental age, as well as severity of autism symptoms, then randomly assigned to one of two intervention conditions that were identical except that one condition was saturated with instruction targeting joint attention, social imitation, and affect sharing (Interpersonal Synchrony condition). Dependent variables included Receptive and Expressive Language T scores (Mullen Scales of Early Learning), nonverbal developmental quotient (mean of Mullen Fine Motor and Visual Reception T scores), frequency of initiation of joint attention and shared positive affect (Communication and Symbolic Behavior Scales Developmental Profile), and imitation score on a structured imitation elicitation task. 
26 of these children were assessed 2 to 6 years after entering the study.  Dependent variables: Stanford Binet VIQ and NVIQ; ADOS algorithm scores.
Results: Ninety percent of the children entered the study NV developmental quotients in the significantly impaired range.  Children in both groups made significant improvement in receptive and expressive language and in imitation (measured within a structured elicitation task) from pre- to post-intervention (p=0.008 to 0.001), but only the Interpersonal Synchrony group made significant gains in joint attention and shared affect (p’s=0.01).  Gains were sustained through the follow-up period, but significant improvement (p=0.001) during this period was limited to language. 
Of the 26 children assessed in the longer-term followup study, 42% and 50% fell with the average range for VIQ and NVIQ, respectively.  73% showed significant improvement in autism symptoms per the ADOS algorithm scores. 

Conclusions: These findings suggest that intensive early intervention emphasizing interpersonal synchrony can improve core deficits of autism involving joint attention, imitation, and shared affect in the short term. Furthermore, enrollment in very early comprehensive intervention that heavily targets communication functioning may facilitate an alteration in the course of development with the potential of achieving typical levels of verbal and nonverbal cognitive functioning, as well as decreased severity of autism symptoms.