NVLD more prevalent than previously thought

The true prevalence of nonverbal learning disability (NVLD), a neurodevelopmental disorder linked to difficulties with math calculations, fine motor skills, and social skills, has been unknown, with only a few previous studies. A new study in JAMA Network Open sought to close that gap and found that NVLD was more prevalent than earlier research had found.¹

Investigators used 3 independent samples of children and adolescents. Two of the samples overselected for children with psychiatric disorders-Healthy Brain Network (HBN), January 1, 2015, to December 31, 2019, and Nathan Kline Institute–Rockland Sample (NKI), January 1, 2011, to December 31, 2018-and the other sample overselected for active maternal smoking during pregnancy-Saguenay Youth Study (SYS), January 1, 2003, to December 31, 2012. The criteria for NVLD was based on the clinical record of deficits in visual-spatial reasoning and impairment in 2 of 4 domains of function: fine-motor skills, math calculation, visual executive functioning, and social skills.

The 3 samples included 2596 children and adolescents. The prevalence of the NVLD was 2.78% in the HBN sample, 3.9% in the NKI sample, and 3.10% in the SYS sample, which means the estimated range for the disorder is 3% to 4%. When extrapolating this prevalence to the US population of persons aged younger than 18 years, there would be an estimated 2.2 to 2.9 million children who had NVLD.

The researchers concluded that the prevalence of NVLD highlights the need to increase awareness of the condition, identify the underlying neurobiological mechanisms, and urge the development and testing of potential interventions for NVLD.

References:

1.    Margolis AE, Broitman J, Davis JM, et al. Estimated prevalence of nonverbal learning disability among North American children and adolescents. JAMA Netw Open. 2020;3(4):e202551. doi: 10.1001/jamanetworkopen.2020.2551