Altered flow of information in attention-deficit/hyperactivity disorder.

Growing evidence suggests that alterations in the connectivity profile of the large-scale brain networks underpin attention-deficit/hyperactivity disorder (ADHD). However, the impact of the brain's asymmetric flow of information on these alterations is unknown. Here, we investigate the brain's asymmetric flow of information in ADHD (N = 355; Control = 189, age = 11.74(2.32); ADHD = 166, age = 11.16(2.20)) using transfer entropy (TE). We report that ADHD is associated with two distinct patterns of the brain's flow of information: the one in which the flow of information is decreased in ADHD and the other in which the flow of information is increased in ADHD. Whereas the first pattern converges on the right visual cortex and the right ventral anterior thalamus as its brain target regions, the second pattern converges on the right frontal operculum. These patterns correlate with the core symptoms and behavioral traits in ADHD, as quantified by the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Scale (SWAN). They include SWAN - Inattention, SWAN - Hyperactive, and SWAN - Total scores, among the others. These alterations further distinguish the individuals with ADHD from the general population. The present study advances the view of the brain's altered functional pathways in ADHD symptomatology by showing the impact of the brain's flow of information on their directionality. It allows for conceptualizing ADHD in terms of alteration in the brain's capacity for the information flow optimization. This should encourage further investigation of this flow of information in neurodevelopmental conditions. This can have implications for the development of the therapeutic strategies which prioritize targeting the brain regions that play pivotal roles in this condition.