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.This work was supported by National Institute of Mental Health
Grants R01-MH59105 and R01-MH63146 to J.T.N. and NIMH R01 MH63255 and NIDA
R21 DA15882 to B.J.C.