The adult outcome of children referred for autism: typology and prediction from childhood

Abstract

Background: Autism Spectrum Disorder is highly heterogeneous, no more so than in the complex world of adult life. Being able to summarize that complexity and have some notion of the confidence with which we could predict outcome from childhood would be helpful for clinical practice and planning. Methods: Latent class profile analysis is applied to data from 123 participants from the Early Diagnosis Study (Lord et al., Archives of General Psychiatry, 2006, 63, 694) to summarize in a typology the multifacetted early adult outcome of children referred for autism around age 2. The form of the classes and their predictability from childhood is described. Results: Defined over 15 measures, the adult outcomes were reduced to four latent classes, accounting for much of the variation in cognitive and functional measures but little in the affective measures. The classes could be well and progressively more accurately predicted from childhood IQ and symptom severity measurement taken at age 2 years to age 9 years. Removing verbal and nonverbal IQ and autism symptom severity measurement from the profile of adult measures did not change the number of the latent classes; however, there was some change in the class composition and they were more difficult to predict. Conclusions: While an empirical summary of adult outcome is possible, careful consideration needs to be given to the aspects that should be given priority. An outcome typology that gives weight to cognitive outcomes is well predicted from corresponding measures taken in childhood, even after account for prediction bias from fitting a complex model to a small sample. However, subjective well-being and affective aspects of adult outcome were weakly related to functional outcomes and poorly predicted from childhood.

Defining Positive Outcomes in More and Less Cognitively Able Autistic Adults

“…We considered IQ and ASD symptoms, not as outcomes, but as two of several features that could be related to positive functioning. For participants at both cognitive levels, the number of outcomes met was associated with verbal IQ (within IQ-defined levels although at a small effect size), aligning with previous analyses on the same sample [Pickles et al, 2020] and past work describing the pervasive associations between verbal IQ and adaptive functioning across development [Bal et al, 2015;Liss et al, 2001], even though they are different constructs.…”

“…More cognitively able describes individuals with a verbal IQ of 70 or above, and less cognitively able describes individuals with a verbal IQ below 70 at the most recent assessment. These two groups have non-overlapping distributions of IQ; with means slightly above 100 for the more cognitively able and in the severe to profound range for less cognitively able adults [Pickles et al, 2020].…”

“…The average ages for joining the study varied for the initial sample (M = 2.5 years, SD = 0.43) and the new recruits (M = 13.3 years, SD = 2.49). In recent analyses of the current subjects, we have empirically derived latent classes of adult outcomes [Pickles et al, 2020], and we have described differences in adulthood between individuals who ever received an ASD diagnosis to those who never have in the course of the study while also considering IQ . The goals of the current analyses build on these papers by attempting to provide ways of conceptualizing practical outcomes.…”

ESCAP practice guidance for autism: a summary of evidence-based recommendations for diagnosis and treatment

“…Follow-up studies, from childhood to adulthood, generally indicate that the severity of core autism symptoms decreases over time and many individuals show marked improvements in social and communication skills as they grow older. Among the strongest predictors of a positive outcome are the development of language and having a non-verbal IQ in or around the average range [70,71]. Within this more cognitively able group, there are a small number of adolescents or young adults who no longer meet diagnostic criteria and show no clear remaining symptoms of autism.…”

A Meta-analysis of Outcome Studies of Autistic Adults: Quantifying Effect Size, Quality, and Meta-regression

“…Moreover, several studies have reported that at the participant level, IQ trajectories are not necessarily stable across time points (Billstedt et al 2005;Cederlund et al 2008;Farley et al 2009;Howlin et al 2004). Thus, IQ may be protective against the poorest outcome profile, but does not guarantee a good outcome (Pickles et al 2020). The mixed results may be explained by individual differences in other factors, such as level of social support (Farley et al 2009;Kobayashi et al 1992), or severity of autism symptoms.…”