Trajectory of Language Development in Autistic Spectrum Disorders

Abstract

Although the emphasis on autism as a language disorder has changed (Rutter, 1978), speech delays continue to be the most common cause of initial referral in autism clinics (Siegel, Pliner, Eschler, & Elliott, 1988). In our longitudinal studies, following two groups of children who were referred for possible autism at age 2, parents’ primary concern was delayed language, followed by delay in developmental milestones other than language and medical problems (such as seizures). Language skills are also the best predictor of later outcome in terms of adaptive skills, school achievement, and independence in adulthood (Howlin & Goode, 1998; Lord & Pickles, 1996; Lord & Schopler, 1989; Venter, Lord, & Schopler, 1992). Language skill remains a predictor whether measured by parent report, spontaneous production (e.g., number of words used on a daily basis, use of phrases), standardized measures of receptive or expressive vocabulary (e.g., the Peabody Picture Vocabulary Test-Third Edition [PPVT-III]; Dunn, 1997), or more sophisticated measures of complex syntax.