Predicting the Presence of Challenging Behaviours at 16 Years Old Using a Population Based Sample of Individuals with Autism Spectrum Disorder (ASD)

Background:  ‘Challenging behaviours’ such as aggression, self-injury and non-compliance occur at high rates in children and adolescents with ASD and have been shown to significantly impact on caregivers’ stress and individual’s daily living and social development.  Identifying risk and protective factors for challenging behaviours in individuals with ASD may increase our understanding of the causes and presentation of these behaviours, providing opportunities for interventions.

Objectives:  To identify whether any characteristics frequently evaluated in youth with ASD can be used to predict challenging behaviours. Using a longitudinal sample, associations between participant characteristics measured at age 12 and later challenging behaviour at age 16 is explored.  

Methods:  A longitudinal, population-based cohort [The Special Needs and Autism Project (SNAP); Baird, Simonoff, Pickles, Chandler, Loucas, Meldrum & Charman, 2006] of youth with ASD (N=94) was used to study predictors of challenging behaviours.  Challenging behaviours were measured at 16 years old using six parent rated items from the Profile of Neuropsychiatric Symptoms (PONS; Santosh, Gringas, Baird, Fiori & Sala, 2015): self-injury, aggression, labile mood, antisocial behaviours, oppositionality and explosive rage.  A hierarchical multiple regression was used to investigate which participant characteristics at 12 years old predicted later Challenging Behaviour score.  The variables in each step are described below:

1) Ability level: IQ, adaptive functioning (Vinelands Adaptive Behaviour Scales), receptive and expressive language (Clinical Evaluation of Language Fundamentals).

2) Autism severity: clinician ratings of ICD-10 symptoms, the Social Communication Questionnaire and the Social Responsiveness Scale.

3) Emotional and behavioural problems: Parent and teacher reports of hyper-activity, emotional symptoms and conduct problems were collected using the Strengths and Difficulties Questionnaire.

4) Additional psychiatric diagnoses: Diagnoses according to the Child and Adolescent Psychiatric Assessment (CAPA) were grouped into three categories: ADHD; oppositional or conduct disorder; any emotional diagnosis.

Results:  Fifty one percent of parents reported adolescents with a clinical diagnosis of ASD to have one or more challenging behaviours that occurred frequently or interfered with everyday life.  The most frequent behaviour was oppositionality (40%), followed by aggression (28%) and explosive rage (20%).  IQ and language level did not significantly predict later challenging behaviour and nor did the addition of autism severity measures in Steps 1 and 2 of the hierarchical regression.  The addition of teacher and parental reports of behavioural and emotional problems produced a significant predictive model and significantly improved the variance explained (ΔR² = 0.28, p<.01).  The addition of CAPA diagnoses improved the model further (ΔR²= 0.11, p<.05.).

Conclusions:  In this population-based sample, challenging behaviours at 16 years old were prevalent and predicted by previous co-occurring mental disorders and emotional and behavioural symptoms. The presence of co-occurring psychiatric disorders are predictive over and above parental and teacher reports of behaviour and therefore those meeting criteria for psychiatric diagnoses may be especially at risk of challenging behaviours.  These findings are in contrast with findings from non-ASD populations where lower IQ, functioning and language level predict challenging behaviours.  With replication these findings may highlight behaviours to identify individuals for early interventions.