Debunking Myths - "SCD is just diet autism."
What is social communication disorder?
Social communication disorder (SCD) is characterized by persistent difficulties with the use of verbal and nonverbal language for social purposes. Primary difficulties may be in social interaction, social understanding, pragmatics, language processing, or any combination of the above.
What is the difference between SCD and autism?
Some overlap exists between autism and SCD. Both conditions involve difficulties initiating and responding to social cues, making it hard for individuals to engage in typical social interactions. However, they differ greatly in many other ways. “One way to distinguish between SCD and ASD is to consider the severity of the individual's difficulties with verbal and nonverbal communication. Individuals with ASD typically have more severe difficulties with both verbal and nonverbal communication than individuals with SCD. Another way to distinguish between SCD and ASD is to consider the presence of restricted and repetitive behaviors. Individuals with ASD typically exhibit restricted and repetitive behaviors, while individuals with SCD do not." Also, notably, autism has an onset in very early childhood and is a developmental disorder, while SCD has an onset in late childhood or early adolescence, and is a communication disorder, not a developmental one.
SCD may be a novel diagnosis in the DSM-V, but children impaired in social uses of language have been recognized for a long time within the speech therapy literature. The first significant article discussing what would later be termed "Social Pragmatic Communication Disorder" (SCD) was published by Rapin and Allen in 1983, where they described a "semantic-pragmatic deficit syndrome" characterizing children with issues like excessive talking, poor comprehension of connected speech, unusual word choices, and inadequate conversational skills, often seen in individuals with autistic traits but not necessarily meeting full criteria for Autism Spectrum Disorder. However, terms used differed among authors and study centers with such children reported as displaying “semantic-pragmatic syndrome,” “semantic-pragmatic difficulties,” “conversational disability,” “pragmatic disability,” “semantic-pragmatic disorder,” and last and most recently “pragmatic language impairment (PLI).”
Earlier studies of autism have demonstrated that social impairments and repetitive-stereotypical behavioral and language problems correlated significantly and, therefore, should be clustered together. However, more recent studies showed that symptoms pertaining to social communication and RRBs did not correlate as highly as expected and that samples with clinically significant symptoms pertaining to a domain may not display symptoms from the other domain at a clinically significant level. Those results supported a distinction between a group of children displaying prominent RRBs and another group displaying social communication problems. The group with RRB symptoms was thought to belong to ASD, whereas the latter group was thought to be separate.
SCD also addressed concerns that some children previously diagnosed with PDD-NOS (or “atypical autism”) would lose their diagnosis and be without services. The category of PDD-NOS listed under PDD in DSM-IV denoted atypical clinical presentations with an incomplete presentation of autism but required clinical support and services. “The PDD-NOS diagnosis described patients with problems in reciprocal social interaction or had symptoms of RRB but did not fit with other diagnoses listed under the rubric of PDD. Because symptoms of RRB are sine qua non for ASD diagnosis under DSM-5, there were suggestions that a subgroup of patients with PDD-NOS (ie, those with social communication problems but without RRB symptoms) may be left without required medical and educational services.”