The dopamine agonist apomorphine differentially affects cognitive performance in alcohol dependent patients and healthy controls.
BACKGROUND
Reduced metabolic activity in frontal brain regions, and reduced striatal dopamine receptor densities have been shown in alcohol dependent patients. Little is known on functional changes in the fronto-striatal-thalamic dopaminergic neurocircuitry in these patients. The objective of this study was to assess sensitivity of prefrontal dopamine receptors in alcohol dependent patients.


METHODS
Male alcohol dependent patients (N=40) and healthy controls (N=39) performed an AX-continuous performance test before and after administration of the DA agonist apomorphine (0.005 mg/kg).


RESULTS
At baseline alcohol dependent patients were slower and less accurate compared to healthy controls. After administration of apomorphine, performance improved in alcohol dependent patients and deteriorated in healthy controls.


CONCLUSIONS
Reduced cognitive performance in alcohol dependent patients compared with healthy controls may indicate dopamine dysfunctioning at the prefrontal level. Improvement of cognitive performance in alcohol dependent patients after administration of apomorphine and deterioration in healthy controls provides evidence for an inverted U-shape relation between dopaminergic functioning and cognitive performance.
Schellekens
Arnt F A
AF
Department of Psychiatry, University Medical Centre St Radboud, Nijmegen, The Netherlands. a.f.a.schellekens@psy.umcn.nl
van Oosterwijck
Armand W A A
AW
Ellenbroek
Bart
B
de Jong
Cor A J
CA
Buitelaar
Jan K
JK
Cools
Lex
L
Verkes
Robbert-Jan
RJ
D000328:Adult; D000437:Alcoholism / Q000150:complications / Q000523:psychology*; D001058:Apomorphine / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D017831:Diagnosis, Dual (Psychiatry); D004298:Dopamine / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000150:complications / Q000523:psychology; D008875:Middle Aged; D011597:Psychomotor Performance / Q000187:drug effects*; D011930:Reaction Time / Q000187:drug effects; D011954:Receptors, Dopamine / Q000187:drug effects; D012959:Socioeconomic Factors
D018491:Dopamine Agonists; D011954:Receptors, Dopamine; D001058:Apomorphine; D004298:Dopamine