The publication of DSM-5 (American Psychiatric Association, 2013) saw the introduction of a new diagnostic label into the psychiatric ‘bible’, “Social (Pragmatic) Communication Disorder” (SCD; see Table 1). As we warily approach this new entity, we might first reasonably wonder what was in the collective mind of the task force when they settled on its name. It is not a name that previously existed (in this form) in the psychiatric literature, nor in the literature on developmental language disorders. But there are clear echoes of earlier designations and the task force must surely have expected us to reflect on those various syndromes in the literature to which this curious designation alludes. Indeed, there has been a veritable chain of syndromes or conditions or deficits that share some portion of the name.

Consider how the newly minted S(P)CD lines up with its various forebears. Table 2 (see below) seeks to align the features of the original version of the Rapin and Allen (1983) syndrome with features that are associated with similarly-named conditions over the intervening years, up to and including DSM-5. A word of caution: in most cases the features listed in the table were not specified by the authors as diagnostic criteria for the condition under investigation; in some cases, they were extracted from relatively informal descriptions. Also, the table is not exhaustive; there are other informal descriptions of similar difficulties, but these are among the most frequently cited. Finally, aligning the features across the conditions was done by art, not by science; readers will likely take issue with some of the alignments. The table represents a good faith (if possibly naïve) effort to track the evolution of this elusive conceptual entity.The lineage of S(P)CD goes back, at least, to Rapin and Allen (1983) who are generally credited with first describing a syndrome which they called “semantic pragmatic syndrome without autism.” In the context of a paper that surveyed the range of developmental language disorders, they described children with the syndrome as producing “syntactically wellformed, phonologically intact” utterances that were “often not really communicative.” They noted “a severe impairment in the ability to encode meaning relevant to the conversational situation, and a striking inability to engage in communicative discourse” as well as impaired comprehension of connected discourse and “seemingly irrelevant responses” to questions. In the 30 years since that time, other scholars have tried to elaborate, or improve upon, that initial description, often also tinkering with the name of the condition under investigation. “Semantic pragmatic syndrome without autism” and its descendants constitute at least a hypothetical family tree for Social (Pragmatic) Communication Disorder.

So what can we learn from this exercise? First, by considering the names employed, we see that there has been an abandonment of the notion of semantic differences as a defining characteristic. The term “semantic” refers to the meaning of words and phrases. Rapin and Allen’s citation of impaired “ability to encode meaning relevant to the conversational situation” and “’canned’ sentences without real semantic content” presumably provided the rationale for including “semantic” in the condition’s original name. But these features disappear from the descriptions over time, even as “semantic” disappears from the names.

There are other features in the original description that have fallen by the wayside, including the quartet of “echolalia,” “pronoun confusion,” “impaired syntax,” and “disruption of prosody.” While Rapin and Allen (1983) considered these as part of the original syndrome, they have not been taken up by more recent scholars. Clinical experience suggests that these features are also frequently noted in the language of people with ASD and, as such, fail to distinguish pragmatic language impairment without autism. Further, some later descriptions have explicitly excluded these features; for example, Rapin (1996) concluded that syntax was “unimpaired” in “semantic-pragmatic deficit disorder”.

The literature reveals an increasing emphasis, over time, on the importance of “pragmatic” language differences which DSM-5 seems to wish to equate with the term “social communication” difficulty. (Is that what those parentheses in the DSM-5 name mean?) A common feature that has persisted across almost all descriptions and that may help to clarify “pragmatic,” as it has been used in these papers, is some form of “difficulty with communicative discourse or conversation.” The DSM-5 definition (criterion A.3) characterizes this feature as “difficulty following rules for conversation and storytelling.”

The “ability to change communication to match context” (DSM-5 criterion A.2) enters the literature with Bishop (1998) but is more clearly emphasized in Volden et al. (2009).

Tracking backward from DSM-5 criterion A.4 (i.e., “difficulties understanding what is not explicitly stated”) is more difficult. There is a possible connection to Rapin and Allen’s (1983) “inability to deal with abstract concepts” but the match is not perfect. DSM seems to emphasize difficulty grasping implied meaning, which is not exactly the same as “comprehension deficits” or trouble with abstract concepts. It is possible that difficulty with implied meaning has not been clearly included in previous descriptions and should be recognized as a new feature in the DSM.

Finally, the DSM criterion A.1, “deficits in using communication for social purposes in a manner that is appropriate for the social context,” presents something of a challenge. It seems to overlap with the A.2 criterion in its focus on appropriateness to context; but “using communication for social purposes” is not just a matter of context. There is some apparent connection to “socially appropriate” conversational responses (Reisinger et al., 2011), but again the match is not perfect. The exact intent of this DSM criterion is simply not clear.

This brief review makes it clear that S(P)CD did not spring, like Athena, “fully armed, from the head of Zeus” (or from the collective heads of the task force members). There is a history here which the diagnostic criteria build on, though some may find the DSM definition less-than-faithful to that history.

Two important empirical questions raised by the DSM definition are: “Do these specific communication differences cluster together in nature?” and “Does this combination exist in a ‘pure’ form, justifying a distinct diagnostic category, or only as difficulties that are invariably a part of some other condition?” Even a brief look at the literature makes it clear that those questions are yet unanswered, largely because the specific features included in the DSM definition of S(P)CD have not yet been systematically examined as a syndrome. While Gibson et al. (2013) sought to distinguish “pure” Pragmatic Language Impairment (PLI) from ASD, the form of PLI that these scholars investigated did not exactly correspond to S(P)CD, and further the results were somewhat equivocal. One might have hoped for a clearer answer to those questions before the diagnosis was formalized in a manual that is intended to be a prominent guide for clinical practice.

A more urgent practical question is: “How will the advent of this diagnostic label affect real people with disabilities?” The task force appears to have been motivated in part by the need to acknowledge the existence of individuals with social communication difficulties (as seen in ASD) who do not have the restricted interests or repetitive behaviors associated with ASD. This seems a worthwhile goal, although the size of that population is as yet unknown. However, if that was the goal, one wonders why the defining characteristics of S(P)CD do not better align with the social communication criteria of ASD; even a casual comparison reveals that the social communication differences identified in S(P)CD are substantively different from the defining characteristics of ASD.

Further, the new diagnosis of S(P)CD is launched to a network of professionals who are singularly unprepared to use it constructively. Aside from any vagueness built into the criteria, few developmental specialists and even fewer mental health professionals are adequately prepared to competently assess pragmatic language impairment.

If we are looking for a silver lining, one might say that the existence of this diagnosis offers yet another testimony to the value of collaborative multidisciplinary assessment teams. Psychologists, developmental pediatricians, and child psychiatrists who do not have access to the expertise of a speech/language professional will be at a distinct disadvantage when it comes to making valid diagnoses of S(P)CD.