The Aberrant Behavior Checklist in a Clinical Sample of Autistic Individuals with Intellectual Disabilities and Co-Occurring Mental Health Problems: Psychometric Properties, Factor Structure, and Longitudinal Measurement Invariance.
The ABC is mostly stable for autistic clients with ID—just don't trust its hyperactivity/noncompliance scores across years.
01Research in Context
What this study did
Nikolai's team tracked 137 autistic clients with intellectual disability across two years. They used the Aberrant Behavior Checklist (ABC) at three time points to see if scores stayed stable.
All clients lived in locked psychiatric units and had at least one extra mental health diagnosis. The researchers ran factor analyses to test if the ABC's five subscales held up over time.
What they found
Four ABC subscales stayed solid: irritability, lethargy, stereotypy, and inappropriate speech. Their factor loadings and means did not shift across the two years.
The hyperactivity/noncompliance subscale failed the test. Its factor structure changed and average scores crept upward, making year-to-year comparisons risky.
How this fits with other research
Horovitz et al. (2011) saw a similar drift, but in the opposite direction: among adults with severe-profound ID (no autism focus), only the PDD/autism subscale moved over the study period. Nikolai now shows that once autism is in the mix, the hyperactivity/noncompliance piece is the shaky one.
Prigge et al. (2013) used the same ABC to flag risk for challenging behavior in adults with ID. Their work treated ABC scores as fixed predictors; Nikolai warns that for autistic clients you can trust four subscales as stable, but not the fifth.
Embregts (2000) found the rival CBCL checklist unreliable in youth with mild ID. Nikolai gives the ABC a cleaner bill of health, at least for four of its five parts, offering clinicians a more robust option.
Why it matters
When you track progress or write treatment goals, keep using the ABC's irritability, lethargy, stereotypy, and inappropriate speech subscales. Treat hyperactivity/noncompliance scores as single-time snapshots only; pair them with direct observation or another informant if you need to chart change in that domain.
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02At a glance
03Original abstract
The Aberrant Behavior Checklist (ABC) was originally developed to evaluate interventions, and is a well-established assessment tool for challenging behaviours in people with intellectual disabilities and autistic people. However, whether the ABC displays longitudinal measurement invariance (i.e., whether it captures the same constructs over time) has been sparsely explored. The aim of the current study is to explore the factor structure, longitudinal measurement invariance, and clinical correlates of the ABC in autistic individuals with intellectual disabilities. Using data from a multicentre study of mental health assessment and treatment in autistic people with intellectual disabilities, the intake ABC scores of 200 autistic individuals with intellectual disabilities were used to explore the ABC factor structure, internal consistency, and clinical correlates (age, gender, level of intellectual disability, autism characteristics, communication skills). Scores across three time points (intake, post-intervention, follow-up) were used to explore longitudinal measurement invariance and internal consistency over time. The original five-factor structure showed a non-optimal but acceptable fit, which was similar or slightly improved compared to previous studies. Associations for some ABC subscales were found to be positive for autism characteristics and negative for communication skills. Four of the five subscales (irritability, social withdrawal, stereotypic behaviour, inappropriate speech) showed residual levels of longitudinal measurement invariance, while one subscale showed noninvariance (hyperactivity/noncompliance). The current study demonstrates the construct validity and applicability of the ABC in autistic individuals with intellectual disabilities, while also indicating that caution is advised for one of its subscales in comparisons across time.
Journal of autism and developmental disorders, 2025 · doi:10.1007/s11336-016-9506-0