Pragmatic language and associations with externalizing behaviors in autistic individuals and those who have lost the autism diagnosis.

Background: Pragmatic language weaknesses, a core feature of autism spectrum disorder (ASD), are implicated in externalizing behavior disorders (Gremillion & Martel, 2014). Particularly in a clinical setting, these co-occurring externalizing disorders are very common in autism; rates of Attentional Deficit-Hyperactive Disorder (ADHD) and Oppositional Defiant Disorder (ODD) are as high as 83% (ADHD) and 73% (ODD; Joshi et al., 2010). It is possible that pragmatic language weaknesses impact the ability to effectively communicate one's needs, which may lead autistic children to utilize externalizing behaviors in order to achieve a desired outcome (Ketelaars et al., 2010; Rodas et al., 2017). Methods: The aim of the current study is to investigate the relationship between pragmatic language, assessed via multiple modalities, and externalizing behaviors, assessed by parent interview, in youth with autistic (n=33) or neurotypical (NT; n=34) developmental histories, along with youth diagnosed with autism, who lost the diagnosis (LAD) by adolescence (n=31). Results: The autism group had significantly more pragmatic language difficulties, and more externalizing behaviors and disorders; ADHD symptoms were particularly more prevalent, while LAD and NT groups did not differ. Challenges in pragmatic language abilities were associated with more externalizing symptoms when controlling for other facts that typically influence such symptoms, including nonverbal cognition, structural language, executive functioning, and autistic characteristics, but did not remain when age was included in the model. Conclusions: We discuss the mechanisms underlying difficult-to-manage externalizing behaviors and implications for interventions and long-term outcomes for youth with and without a history of autism.