Social (pragmatic) communication disorder (SCD) is a new diagnostic category included under Communication Disorders in the Neurodevelopmental Disorders section of the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) .SCD is defined by a primary deficit in the social use of nonverbal and verbal communication . Individuals with SCD may be characterized by difficulty in using language for social purposes, appropriately matching communication to the social context, following rules of the communication context (e.g., back and forth of conversation), understanding nonliteral language (e.g., jokes, idioms, metaphors), and integrating language with nonverbal communicative behaviors. Sufficient language skills must be developed before these higher-order pragmatic deficits can be detected, so a diagnosis of SCD should not be made until children are 4–5 years of age. Social communication disorder can co-occur with other communication disorders in the DSM-5 (these include language disorder, speech sound disorder, childhood-onset fluency disorder, and unspecified communication disorder), but cannot be diagnosed in the presence of autism spectrum disorder (ASD)
SCD and ASD are common in the requirement of deficits in social communication skills, but individuals with SCD cannot evidence restricted interests, repetitive behaviors, insistence on sameness, or sensory abnormalities. It is essential to rule out a diagnosis of ASD by verifying the lack of these additional symptoms, currently or by history, before assigning a diagnosis of SCD. Thus, the criteria for SCD are qualitatively different from ASD and are not equivalent to “mild ASD.” However, whether children display the specific pattern of the SCD diagnostic criteria is still an empirical question.
Distinguishing pragmatic impairments from ASD
Given that impairments in social communication are a hallmark feature of ASD, overlap in the symptomatology of SCD and ASD is expected. Specifically, children with ASD who have adequate structural language abilities may have pragmatic difficulties such as verbosity, overly formal speech, and trouble taking turns in conversation. These pragmatic deficits are expressed in the context of a larger constellation of ASD symptoms, which include impairments in social reciprocity and the presence of restricted interests and repetitive behaviors. On the other hand, it is important to note that pragmatic language deficits have been reported to occur without the impairing social deficits and repetitive behaviors indicative of ASD, suggesting that two distinct patterns of symptoms exist.
Pragmatic impairments and other developmental or behavior problems
Pragmatic language difficulties have been described in a variety of psychiatric and neurodevelopmental disorders, including schizophrenia bipolar disorder , and attention deficit hyperactivity disorder ,among others. With respect to attention deficit hyperactivity disorder, it has been hypothesized that the primary symptoms of the disorder (i.e., impulsiveness, inattention, hyperactivity) may cause impairments in social communication, which result in additional limitations on communication, social participation, and academic achievement . Pragmatic impairments have also been found frequently among children with neurologic conditions, such as epilepsy and among children with behavioral problems . Additional research is needed to understand the impact that SCD and pragmatic language impairments have on the acquisition of academic skills, problematic behaviors, and neuropsychiatric disorders.