An integrative theory of attention-deficit/ hyperactivity disorder based on the cognitive and affective neurosciences.

Attention-deficit/hyperactivity disorder (ADHD) is a behavioral syndrome that arises in early childhood, often co-occurs with conduct disorder and leads, developmentally, to antisocial behavior and substance abuse. Models from cognitive and affective neuroscience have been invoked in an effort to understand the development of ADHD, leading to a broad array of interrelated theories and hypothesized mechanisms. In this paper, we highlight core mechanisms that may cut across several theories and constructs, and thus provide some leverage for further study and conceptualization from a neuroscience perspective. We emphasize the joint operations of frontostriatal and frontocerebellar neural loops in detecting and predicting what and when important events in the environment will occur and their interaction with frontoamygdala loops in assigning emotional significance to these events. We note that weaknesses in the development of these basic operations could lead to decrement in the development of cognitive and affective control and other mental operations mediated by prefrontal cortex during development. In turn, such decrement could lead to many of the phenotypic cognitive and neuropsychological features seen in children with ADHD.