title: Dopaminergic function and intertemporal choice.
abstract: The discounting of delayed rewards, also known as temporal or delay discounting, is intrinsic to everyday decisions and can be impaired in pathological states such as addiction disorders. Preclinical and human studies suggest a role for dopaminergic function in temporal discounting but this relationship has not yet been verified using molecular imaging of the living human brain. Here, we evaluated dopaminergic function in temporal discounting using positron emission tomography (PET) with two different dopaminergic ligands assessing three populations in whom temporal discounting has been shown to be impaired. First, we show using [11C]raclopride PET that in pathological gamblers, greater temporal discounting correlates with decreased ventral striatal binding potential, convergent with translational findings of lower nucleus accumbens D2/D3 receptor density in high-impulsive rodents. Temporal discounting also correlates with lower ventral striatal dopamine release in response to high-reward magnitude suggesting that dopamine-mediated devaluation of larger delayed rewards may drive choice preferences. Second, we show using [18F]fluorodopa PET that in Parkinson's disease, temporal discounting correlates with greater left caudate dopaminergic terminal function. Finally, in subjects with Parkinson's disease and dopamine medication-induced behavioral addictions, temporal discounting is further correlated with greater dopaminergic terminal function in the anterior putamen. These findings provide insights into the relationship between striatal dopamine function and temporal discounting, and its potential role in pathological disorders and mechanisms underlying treatment interventions.
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Joutsa
authors.affiliation: 1] Department of Psychiatry, Cambridge University, Cambridge, UK [2] Behavioral and Clinical Neurosciences Institute, Cambridge University, Cambridge, UK.
authors.forename: V
authors.initials: V
authors.lastname: Voon
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Johansson
authors.affiliation: Department of Psychiatry, University of Oulu and Lappi Hospital District, Rovaniemi, Finland.
authors.forename: S
authors.initials: S
authors.lastname: Niemelä
authors.affiliation: Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Bergman
authors.affiliation: 1] Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland [2] Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.
authors.forename: V
authors.initials: V
authors.lastname: Kaasinen
mesh_terms: D000328:Adult; D000368:Aged; D000978:Antiparkinson Agents / Q000009:adverse effects; D016739:Behavior, Addictive / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000523:psychology; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism; D016022:Case-Control Studies; D002421:Caudate Nucleus / Q000000981:diagnostic imaging* / Q000378:metabolism; D065786:Delay Discounting; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D005715:Gambling / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000523:psychology; D049268:Positron-Emission Tomography; D020891:Raclopride; D019275:Radiopharmaceuticals; D011954:Receptors, Dopamine / Q000378:metabolism; D009435:Synaptic Transmission; D066328:Ventral Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism; D055815:Young Adult
chemical_list: D000978:Antiparkinson Agents; D018492:Dopamine Antagonists; D019275:Radiopharmaceuticals; D011954:Receptors, Dopamine; C043437:fluorodopa F 18; D020891:Raclopride; D004295:Dihydroxyphenylalanine; D004298:Dopamine