The fuzzy boundaries of the social (pragmatic) communication disorder (SPCD): Why the picture is still so confusing?

Introduction: Since the introduction of Social (Pragmatic) Communication Disorder (SPCD) in the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) in 2013, a debate has arisen in the scientific community about its usefulness in differential diagnosis for other clinical categories such as Autism Spectrum Disorder (ASD) and Specific Language Impairment (SLI). Indeed, SPCD criteria share a common deficit in communication and pragmatic skills with these diagnostic entities. Available assessment tools seem scarce and not sensitive enough to clarify diagnostic criteria and clinical boundaries. This study aims to review the existing literature on diagnostic screening for SPCD to highlight confounding variables in the domains examined, overlap with other diagnostic entities, and lack of specificity of available assessment tools in identifying the core deficits of the disorder. Methods: The search strategy was defined by combining the following keywords: "social pragmatic communication disorder," "DSM-5," "differential diagnosis," and "child." The search was performed in three databases: Medline (PubMed), Scopus, and Web of Science. All studies published between 2013 and April 2023, written in English, and with a major focus on SPCD were included in the review. Results: After the screening for the eligibility, 18 studies were included in the review. Most of these studies aimed to investigate the differential diagnosis between SPCD and other diagnostic categories (e.g., specific language impairment and autism spectrum disorder). Of these researches, only 6 were ad hoc experimental studies, while the others were based on previously collected databases. Conclusions: SPCD seems to have its own peculiarities and characteristics, indicating its clinical relevance, as emphasized by the DSM-5. However, the lack of specific instruments and a number of confounding variables make it difficult to identify and differentiate SPCD from other diagnostic entities. Further research is needed to overcome the lack of specific clinical instruments and lack of empirical studies.