Transdiagnostic neurocognitive dysfunction in children and adolescents with mental illness

Robust evidence from adult samples indicates that neurocognitive dysfunction is a hallmark of many mental illnesses, contributing to the loss of daily function and quality of life that these illnesses cause. However, it is still unclear whether neurocognitive deficits associated with mental illnesses begin to manifest well before adulthood or impact treatment response. Here we address this gap by evaluating neurocognitive function in four groups of children and adolescents with different mental illnesses compared to their matched healthy peers. Our team evaluated the neurocognitive performance of youth diagnosed with attention deficit and hyperactivity disorder ( N = 343), anorexia ( N = 40), first onset psychosis ( N = 25) and functional neurological disorder ( N = 56) versus age-matched healthy controls ( N = 483), cross-sectionally. Performance was assessed using an objective assessment battery designed for use across diagnoses and settings and validated for its correlations with underlying brain structure and function. The following cognitive domains were assessed: sustained attention, cognitive flexibility, decision speed, executive function, information processing speed, psychomotor response speed, response inhibition, verbal memory and working memory. Distinct profiles of neurocognitive dysfunction were detected for each diagnosis relative to the healthy reference group. Youth with first onset psychosis displayed the most severe and generalized impairments across domains of sustained attention, verbal memory, response inhibition, cognitive flexibility, information processing speed and working memory. Children and adolescents with attention deficit and hyperactivity disorder showed impairments in multiple domains of at least moderate severity with the most pronounced impairments in executive function, sustained attention and working memory. Children and adolescents with anorexia displayed more specific moderate impairments limited to cognitive flexibility, response inhibition, sustained attention, decision speed and verbal memory. Impairments in functional neurological disorder were also relatively specific and moderate, limited to executive function, working memory, cognitive flexibility, decision speed and information processing speed. These findings suggest that neurocognitive impairment in mental illness is transdiagnostic and can be detected as early as childhood or adolescence with standardized computerized testing.