In Search of Subtypes of Children With Developmental Disabilities Using the WISC-V: A Latent Profile Analysis

PURPOSE: Identifying subtypes within autism spectrum disorder (ASD) has often been attempted to better understand the significant heterogeneity within the spectrum. Profiles of cognitive functioning have frequently been investigated as possible subtype definitions, but most studies have relied on relatively small sample sizes and higher-functioning samples, and few have used advanced statistical techniques to obtain estimates of underlying profiles of IQ in ASD. The purpose of this study was to use latent profile analysis to identify possible subgroups of children with ASD and other neurodevelopmental disabilities using the Wechsler Intelligence Scale for Children-5th Edition (WISC-V) across a range of ability levels. METHODS: We used latent profile analysis with a clinical sample of 727 youth (ages 6-16) referred for neurodevelopmental evaluations. We also completed a multigroup bifactor confirmatory factor analysis of the clinical sample compared to the WISC-V standardization sample. RESULTS: We did not find distinct cognitive profiles based on the WISC-V index scores; results indicated a continuum of the g factor of intelligence instead of distinct patterns of strengths and weaknesses across IQ subscales. A multigroup bifactor confirmatory factor analysis revealed partial strong invariance when comparing the two clinical groups to the WISC-V standardization sample, but full strong invariance within the neurodevelopmental groups and substantive explained variance of the processing speed index above and beyond FSIQ. CONCLUSION: Alternative methods and measurements are needed to identify potential cognitive subtypes of children with autism and other neurodevelopmental disabilities. Processing speed (but not other WISC-V indexes) may be of unique clinical interpretability above and beyond FSIQ.