Ten years of using the APACS test: a multistudy cross-diagnostic analysis of pragmatic profiles and their relationship with Theory of Mind

Pragmatic impairments are largely documented, yet rarely considered in clinical practice, also owing to a poor characterization of pragmatic profiles across conditions, as well as some overlap with theory of mind (ToM) in the conceptualization of pragmatics. Here, we present the outcome of a 10-year programme that started with creating a novel test, the Assessment of Pragmatic Abilities and Cognitive Substrates (APACS)–which we evolved by its application alongside ToM assessment in seven clinical groups (i.e. amyotrophic lateral sclerosis, multiple sclerosis, right-hemisphere stroke, Parkinson’s disease, traumatic brain injury, schizophrenia and dyslexia). The multistudy cross-diagnostic analysis of 454 participants revealed that receptive pragmatic skills were impaired in all clinical groups compared with controls, with schizophrenia showing the most severely impaired profile, whereas expressive pragmatic skills were impaired in four neurological conditions (i.e. Parkinson’s disease, amyotrophic lateral sclerosis, right-hemisphere stroke and traumatic brain injury). The association with ToM was limited to receptive pragmatics and was moderate in the whole sample. Overall, pragmatic impairment emerged as a diffuse feature of neurological and psychiatric illnesses, which contributes to defining complex socio-communicative phenotypes but cannot be equated to a social cognition deficit and should hence be the target of specific assessment and intervention.