An analysis of the criteria used to diagnose children with Nonverbal Learning Disability (NLD).

Based on a review of the literature, the diagnostic criteria used for children with nonverbal learning disabilities (NLD) were identified as follows: (a) low visuospatial intelligence; (b) discrepancy between verbal and visuospatial intelligence; (c) visuoconstructive and fine-motor coordination skills; (d) visuospatial memory tasks; (e) reading better than mathematical achievement; and (f) socioemotional skills. An analysis of the effect size was used to investigate the strength of criteria for diagnosing NLD considering 35 empirical studies published from January 1980 to February 2011. Overall, our results showed that the most important criteria for distinguishing children with NLD from controls were as follows: a low visuospatial intelligence with a relatively good verbal intelligence, visuoconstructive and fine-motor coordination impairments, good reading decoding together with low math performance. Deficits in visuospatial memory and social skills were also present. A preliminary set of criteria for diagnosing NLD was developed on these grounds. It was concluded, however, that-although some consensus is emerging-further research is needed to definitively establish shared diagnostic criteria for children with NLD.