Specific language impairment: a convenient label for whom?

Abstract

Background: The term 'specific language impairment' (SLI), in use since the 1980s, describes children with language impairment whose cognitive skills are within normal limits where there is no identifiable reason for the language impairment. SLI is determined by applying exclusionary criteria, so that it is defined by what it is not rather than by what it is. The recent decision to not include SLI in DSM-5 provoked much debate and concern from researchers and clinicians.

Aims: To explore how the term 'specific language impairment' emerged, to consider how disorders, including SLI, are generally defined and to explore how societal changes might impact on use the term.

Methods & procedures: We reviewed the literature to explore the origins of the term 'specific language impairment' and present published evidence, as well as new analyses of population data, to explore the validity of continuing to use the term.

Outcomes & results and conclusions & implications: We support the decision to exclude the term 'specific language impairment' from DSM-5 and conclude that the term has been a convenient label for researchers, but that the current classification is unacceptably arbitrary. Furthermore, we argue there is no empirical evidence to support the continued use of the term SLI and limited evidence that it has provided any real benefits for children and their families. In fact, the term may be disadvantageous to some due to the use of exclusionary criteria to determine eligibility for and access to speech pathology services. We propose the following recommendations. First, that the word 'specific' be removed and the label 'language impairment' be used. Second, that the exclusionary criteria be relaxed and in their place inclusionary criteria be adopted that take into account the fluid nature of language development particularly in the preschool period. Building on the goodwill and collaborations between the clinical and research communities we propose the establishment of an international consensus panel to develop an agreed definition and set of criteria for language impairment. Given the rich data now available in population studies it is possible to test the validity of these definitions and criteria. Consultation with service users and policy-makers should be incorporated into the decision-making process.

Keywords: child language; language impairment; specific language impairment.

Figure 1

Evolution of terminology describing child language difficulties prior to the introduction and adoption of the term ‘specific language impairment’.

Figure 2

Language composite measure plotted against non-verbal IQ for 603 eight-year-old children in the Iowa study.

Figure 3

Receptive and expressive language standard scores for the CELF-P and CELF-4 plotted against non-verbal IQ for children in the Early Language in Victoria Study (ELVS) at age 4 years for 1556 children and at age 7 years for 1197 children.

Figure 4

Data from three population studies illustrating the social gradient in language outcomes amongst 5-year-old children: (a) naming vocabulary of 5-year-old children in the Millennium Cohort Study (MCS). Children are grouped in quintiles according to the Index of Multiple Deprivation (IMD); (b) naming vocabulary of 5-year-old children in the Growing Up in Scotland (GUS) study. Children are grouped in quintiles according to the IMD; and (c) Core Language standard scores for 5-year-old children in the Early Language in Victoria Study (ELVS). Children are grouped in quintiles according to the Socio-Economic Indexes for Areas (SEIFA). For all graphs, the reference line is the standardization mean for the assessment.