ADHD: increased dopamine receptor availability linked to attention deficit and low neonatal cerebral blood flow.
Attention-deficit-hyperactivity disorder (ADHD), while largely thought to be a genetic disorder, has environmental factors that appear to contribute significantly to the aetiopathogenesis of the disorder. One such factor is pretern birth with vulnerable cerebrovascular homeostasis. We hypothesised that cerebral ischaemia at birth could contribute to persistent deficient dopaminergic neurotransmission, which is thought to be the pathophysiological basis of the disorder. We examined dopamine D(2/3) receptor binding with positron emission tomography (PET) using [11C] raclopride as a tracer, and continuous reaction times (RT) with a computerized test of variables (TOVA) in six adolescents (12-14 years of age, one female) who had been examined with cerebral blood flow (CBF) measurements at preterm birth and had a subsequent history of attention deficit. We found that high dopamine receptor availability ('empty receptors') was linked with increased RT and RT variability, supporting the concept of a dopaminergic role in symptomatology. High dopamine receptor availability was predicted by low neonatal CBF, supporting the hypothesis of cerebral ischaemia as a contributing factor in infants susceptible to ADHD.
Centre of Functionally Integrative Neuroscience and PET Centre, Aarhus University Hospital, Aarhus, Denmark. hclou@inet.uni2.dk
Hans C
HC
Lou
Pedro
P
Rosa
Ole
O
Pryds
Hanne
H
Karrebaek
Jytte
J
Lunding
Paul
P
Cumming
Albert
A
Gjedde
D000293:Adolescent; D001288:Attention / Q000502:physiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002250:Carbon Radioisotopes; D002648:Child; D002675:Child, Preschool; D003342:Corpus Striatum / Q000098:blood supply / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D020891:Raclopride; D011930:Reaction Time / Q000502:physiology; D011954:Receptors, Dopamine / Q000502:physiology*; D017448:Receptors, Dopamine D2 / Q000502:physiology; D050637:Receptors, Dopamine D3; D012307:Risk Factors; D014055:Tomography, Emission-Computed
D002250:Carbon Radioisotopes; C493593:DRD3 protein, human; D011954:Receptors, Dopamine; D017448:Receptors, Dopamine D2; D050637:Receptors, Dopamine D3; D020891:Raclopride