Developmental trajectories of verbal and nonverbal skills in individuals with a history of specific language impairment: from childhood to adolescence.

PURPOSE To investigate the longitudinal trajectories of verbal and nonverbal skills in individuals with a history of specific language impairment (SLI) from childhood to adolescence. This study focuses on SLI only and investigates within-participant measures across abilities. METHOD Verbal and nonverbal skills were assessed in 242 children with a history of SLI at ages 7, 8, 11, 14, 16, and 17. Discrete factor growth modeling was used to examine developmental trajectories for the whole group and to identify subgroups on the basis of a novel, developmental, multidimensional approach. RESULTS When expressive language, receptive language, and nonverbal skills were scaled to a common metric, the group of individuals with a history of SLI as a whole had stable skills growth throughout the 10-year time frame. Seven language subgroups were identified, but these differed only in severity and did not display mutually distinctive patterns of growth development. In contrast, 6 nonverbal skills subgroups were identified, and their trajectories did differ significantly, with evidence of deceleration in around one third of the sample. CONCLUSION Individuals with a history of SLI show steady language growth from age 7. However, different patterns of growth of nonverbal skills are observed from childhood to adolescence.