Developmental trajectories of speech and language in neglected children aged 3 to 5 years: Results of the ELLAN study.

Background: Neglected children are at high risk for significant difficulties in speech and language development. Because no longitudinal study has been conducted to date, the dynamic description of development during the preschool period is unknown.

Objectives: Establish the developmental trajectories of speech sounds, receptive and expressive vocabulary, and morphosyntax among neglected children during the preschool years and compare them with those of non-neglected children.

Participants And Setting: Participants are 69 neglected children and 99 same age non-neglected peers (37 and 46 males respectively) recruited at 36 months of age. Data were collected at home.

Methods: Data were collected at six-month intervals between the ages of 3 and 5.5 years using psychometrically robust tools. Neglected and control groups were compared according to age using repeated measures ANOVAs on all variables. A discrete mixture model for clustering longitudinal data was used for testing the heterogeneity of the language trajectories among neglected children.

Results: The language development of the neglected children as a whole group is lower than that of the control group for all variables. Two subgroups are identified within the neglected group: one with a developmental trajectory similar to that of the non-neglected children, and another whose trajectory is far below that of the control group. The effect sizes of these differences vary between 1.4 and 3 standard deviations under the mean.

Conclusions: A large proportion of neglected children present significant speech and language difficulties from the age of 3, but some of them catch up and develop similarly to non-neglected children.