18971
Cognitive and Adaptive Functioning of Children Who Lose Their ASD Diagnosis
Emerging literature has indicated that a subset of children with a documented Autism Spectrum Disorder (ASD) lose their diagnosis and function in the average range of cognition and behavior. Following an early ASD diagnosis, these children experience significant improvements in ASD symptoms, cognitive abilities and adaptive skills during their toddler years. Children who lose an ASD diagnosis might be expected to display residual difficulties in social or language functioning. This study aims to characterize children who lose the diagnosis at an early age.
Objectives:
To compare the cognitive and adaptive functioning of toddlers who demonstrate highly positive outcomes from an early ASD diagnosis to peers with high functioning autism and to typically developing (TD) peers.
Methods:
Developmental and diagnostic evaluations were conducted at approximately 26 months following positive screening on an autism-specific screener (MCHAT(-R)). The Autism Diagnostic Observation Schedule (ADOS), Mullen Scales of Early Learning (Mullen), Vineland Adaptive Behavior Scales (VABS II), and Childhood Autism Rating Scale (CARS) were completed. Diagnosis was assigned based on the clinical judgment of experienced clinicians. At approximately 50 months, children were re-evaluated.
The current study utilizes three groups of children (Optimal Progress (OP), HFA, TD). The OP group includes children who initially met criteria for an ASD, no longer meet criteria for any ASD, and demonstrate functioning in the average range (within 1.5SD of the mean) on standardized measures of cognition, language, social and communicative skills. Children in the HFA group met criteria for an ASD at both evaluations and are functioning within 1.5SD of the mean on cognitive measures. Children in the TD group did not meet criteria for any clinical diagnosis and are functioning within 1.5SD of the mean on cognitive and adaptive measures.
Results:
Children in the OP group (N=19) were matched to HFA (N=19) and TD peers (N=19) on gender and age at re-evaluation. The groups did not differ in median household income (p=.870) or ethnicity (p=.203). ANOVAs were utilized to compare the cognitive and adaptive functioning of the groups at re-evaluation (mean age = 50.92 months). No group differences were found in visual receptive, fine motor or receptive language abilities. In the domain of expressive language, the OP group demonstrated weaker skills than their TD peers (p=.031) and comparable skills to their HFA peers (p=.937). In terms of adaptive abilities, the OP group demonstrated stronger skills than their peers with HFA across domains (Communication, p=.008; Daily Living, p=.003; Motor, p=.006; Socialization, p<.001), and comparable skills to their TD peers (p>.05 across domains).
Conclusions:
By age four, children who demonstrate Optimal Progress from an early ASD diagnosis are functioning comparably to TD peers cognitively and adaptively. These children continue to demonstrate weakness in expressive language skills. This supports existing research with older children with Optimal Outcomes who continue to show mild deficits in pragmatic language. In sum, in addition to losing the symptoms associated with ASD, children who demonstrate Optimal Progress in their toddler years are largely indistinguishable from TD peers in the areas of cognitive and adaptive skills.