Developmental Language Disorder Page ContentWhat ARE Developmental Language Disorders?Rare is the layperson who has heard of Developmental Language Disorder (DLD). This is not because DLD is rare or inconsequential. In the United States, DLD is 50 times more prevalent than hearing impairment and five times more prevalent than autism (Centers for Disease Control and Prevention, 2015). Children with DLD are considerably slower than other children to develop spoken vocabulary and grammar despite normal intelligence and ample opportunity. DLD is a life-long condition (Nippold & Schwarz, 2002) that impairs social (Botting & Conti‐Ramsden, 2008) and academic (Alloway, & Stein, 2014) functions. If it is prevalent, life-long, and functionally disabling, why is the public unaware of it? We view the lack of public awareness as one problem in a cycle of problems that include a lack of clarity in talking about DLD to each other and to those outside of the profession; a lack of recognition of DLD on the part of families, teachers, and others who work with children; a scarcity of valid procedures for identifying DLD; and a lack of research efforts aimed at DLD. These problems feed each other and the result is that we as a profession too often fail children with DLD. In the Word Learning Laboratory, we are working towards solutions to this crisis.Problems Terminology is inconsistent. There is no universally accepted label for DLD; in fact, there are 132 different English labels for this condition in current use (Bishop, 2014). This variability presents a barrier to finding, understanding, communicating, and applying relevant information about the disorder—goals pursued by researchers, clinicians, and parents. The condition is invisible. Children with DLD often pass unnoticed by parents and teachers. By U.S. law, children with DLD severe enough to limit their academic success must be identified and served in the public schools. But children with DLD do not look different from other children, so the problem is not apparent to the eye. They may not present with weaknesses in clarity of speech, so the problem is not apparent to the ear. The result is massive under-identification of and intervention for children with DLD (Tomblin, Records, Buckwalter, Zhang, Smith, & O'Brien, 1997). The diagnostic process requires refinement. DLD is a condition identified by the presence of some symptoms and the absence of others (Dollaghan, 2004). Diagnosis is made relative to patterns of normal development, and normal trajectories can be highly variable. Standardized tests of language can aid that normative comparison but cut-offs between "normal" and "disordered" vary widely from school to school or clinic to clinic. There are high rates of co-occurrence between DLD and other neurodevelopmental disorders, making differential diagnosis difficult. Finally, there is no agreed upon means of judging the functional impact of DLD. These issues limit the identification of children with DLD and ultimately prevent children from receiving the services they need. The condition is under-researched. DLD receives less attention from researchers and funding agencies than other neurodevelopmental conditions that are comparable in prevalence and severity. Between 1985 and 2009, the number of publications on DLD was three times lower than developmental dyslexia, ten times lower than speech sound disorder, and 16 times lower than ADHD (Bishop, 2010). In 2008-09, NIH spent 18 times more dollars on ADHD research than DLD research (Bishop, 2010). Solutions Adopt consistent diagnostic criteria and terminology. Members of the CATALISE consortium have worked to build a consensus on identification criteria (Bishop, Snowling, Thompson, Greenhalgh, & the CATALISE consortium, 2016) and terminology (Bishop, Snowling, Thompson, Greenhalgh, & the CATALISE-2 consortium, 2017). The criteria specify appropriate reasons for referral, sources of information, areas to assess, and ways to consider co-occurring conditions. The consensus term was "developmental language disorder." We have adopted this terminology in the Word Learning Laboratory and we are working to update our diagnostic battery to comply with the CATALISE recommendations. Public awareness campaigns. There is growing international concern about the lack of public awareness of DLD. In response, there are public awareness campaigns involving informational videos in England (RALLI http://www.afasic.org.uk/2012/05/ralli-video-campaign-to-raise-awareness-of-sli/) and social media in Australia (#DevLangDis https://www.symplur.com/healthcare-hashtags/devlangdis/). With our colleagues Jacob Michaelson and Natoshia Askelson, we are developing a U.S. campaign. Stay tuned! Contribute to the research base. In the Word Learning Laboratory we are interested in how people of all ages and abilities learn, remember, and use words. But we are particularly focused on the word learning challenges facing people with DLD. We currently have two funded research projects on DLD as well as collaborative projects with students and colleagues. Visit our projects tab to find out more.ReferencesAlloway, T. P., & Stein, A. (2014). Investigating the link between cognitive skills and learning in non-comorbid samples of ADHD and SLI. International Journal of Educational Research, 64, 26-31.Bishop, D. V. (2010). Which neurodevelopmental disorders get researched and why?. PLoS One, 5(11), e15112.Bishop, D. V. M. (2014). Ten questions about terminology for children with unexplained language problems. International Journal of Language & Communication Disorders, 49(4), 381-415.Bishop, D. V. M., Snowling, M. J., Thompson, P. A., & Greenhalgh, T. (2016). CATALISE: a multinational and multidisciplinary Delphi consensus study. Identifying language impairments in children. PLoS One, 11(7), e0158753.Bishop, D. V., Snowling, M. J., Thompson, P. A., & Greenhalgh, T. (2017). Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: Terminology. Journal of Child Psychology and Psychiatry.Botting, N., & Conti‐Ramsden, G. (2008). The role of language, social cognition, and social skill in the functional social outcomes of young adolescents with and without a history of SLI. British Journal of Developmental Psychology, 26(2), 281-300.Centers for Disease Control and Prevention. Downloaded August 26, 2015 from http://www.cdc.gov/lifestages/children.html.Dollaghan, C. A. (2004). Taxometric analyses of specific language impairment in 3-and 4-year-old children. Journal of Speech, Language, and Hearing Research, 47(2), 464-475.Nippold, M. A., & Schwarz, I. E. (2002). Do children recover from specific language impairment?. International Journal of Speech-Language Pathology, 4(1), 41-49.Pawlowska, M. (2014). Evaluation of three proposed markers for language impairment in English: A meta-analysis of diagnostic accuracy studies. Journal of Speech, Language, and Hearing Research, 2261-2273. Porter, K.L., Ash, A.C., Redmond, S., & Oetting, J. (2016). Caregiver perceptions of diagnostic labels applied to their children with language/reading impairments. Seminar Presentation at the American Speech Language Hearing Association Annual Conference, Boston, MA. Tomblin, J. B., Records, N. L., Buckwalter, P., Zhang, X., Smith, E., & O'Brien, M. (1997). Prevalence of specific language impairment in kindergarten children. Journal of Speech, Language, and Hearing Research, 40(6), 1245-1260.