Global developmental delay and its relationship to cognitive skills


    The authors are grateful to Sébastien Dubé for assistance with statistical analysis and Alba Rinaldi for secretarial assistance. Michael Shevell is grateful for the support of the MCH Foundation during the preparation of this manuscript.

Dr Michael Shevell at Division of Child Neurology, Montreal Children’s Hospital, 2300 Tupper Street, Montreal, Quebec, H3H 1P3, Canada. E-mail:


Global developmental delay (GDD) is defined as evidence of significant delays in two or more developmental domains. Our study determined the cognitive skills of a cohort of young children with GDD. A retrospective chart review of all children diagnosed with GDD within a single developmental clinic was carried out. Scores on fine motor (Peabody Developmental Motor Scale 2), expressive language (Expressive One Word Picture Vocabulary Test) and receptive language (Reynell Developmental Language Scales or Clinical Evaluation of Language Fundamentals – Preschool 2) testing, and cognitive performance (Wechsler Preschool and Primary Scale of Intelligence, Third Edition) were obtained. A multiple regression analysis was performed and correlations obtained. Results from a total of 93 patients (86 males, seven females) were retained for analysis. Mean age was 3 years 8 months (SD 10mo, range 2.5–4.75y). Cognitive scores were widely distributed, with 73% of participants displaying a global IQ score of 70 or more, despite concurrent global delay. Significant correlation was present for fine motor and expressive language scores, when isolated and compared with cognitive performance (p values of 0.04 and 0.05 respectively). The conclusion was made that an initial diagnosis of GDD is not necessarily associated with objective cognitive impairment.