The dual pathway model of AD/HD: an elaboration of neuro-developmental characteristics.
The currently dominant neuro-cognitive model of Attention Deficit Hyperactivity Disorder (AD/HD) presents the condition as executive dysfunction (EDF) underpinned by disturbances in the fronto-dorsal striatal circuit and associated dopaminergic branches (e.g. meso-cortical). In contrast, motivationally-based accounts focus on altered reward processes and implicate fronto-ventral striatal reward circuits and those meso-limbic branches that terminate in the ventral striatum especially the nucleus accumbens. One such account, delay aversion (DEL), presents AD/HD as a motivational style-characterised by attempts to escape or avoid delay-arising from fundamental disturbances in these reward centres. While traditionally regarded as competing, EDF and DEL models have recently been presented as complimentary accounts of two psycho-patho-physiological subtypes of AD/HD with different developmental pathways, underpinned by different cortico-striatal circuits and modulated by different branches of the dopamine system. In the current paper we describe the development of this model in more detail. We elaborate on the neuro-circuitry possibly underpinning these two pathways and explore their developmental significance within a neuro-ecological framework.
Sonuga-Barke
Edmund J S
EJ
Department of Psychology, Centre for the Study of Psychological Development, University of Southampton, Southampton S017 1BJ, UK. ejb3@soton.ac.uk
D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology; D003072:Cognition Disorders / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D008606:Mental Processes / Q000502:physiology*; D008959:Models, Neurological; D008960:Models, Psychological; D009434:Neural Pathways / Q000503:physiopathology*; D012054:Reinforcement, Psychology