A pilot study on the association between the blood oxygen level-dependent signal in the reward system and dopamine transporter availability in adults with attention deficit hyperactivity disorder

Abstract

Background. It is well-known that attention deficit hyperactivity disorder (ADHD) is associated with changes in the dopaminergic system. However, the relationship between central dopaminergic tone and the blood oxygen level-dependent (BOLD) signal during receipt of rewards and penalties in the corticostriatal pathway in adults with ADHD is unclear. Methods. Single-photon emission computed tomography with [99mTC]TRODAT-1 was used to assess striatal dopamine transporter (DAT) availability. Event-related functional magnetic resonance imaging was conducted on subjects performing the Iowa Gambling Test. Result. DAT availability was found to be associated with the BOLD response, which was a covariate of monetary loss, in the medial prefrontal cortex (r = 0.55, P = .03), right ventral striatum (r = 0.69, P = .003), and right orbital frontal cortex (r = 0.53, P = .03) in adults with ADHD. However, a similar correlation was not found in the controls. Conclusions. The results confirmed that dopaminergic tone may play a different role in the penalty-elicited response of adults with ADHD. It is plausible that a lower neuro-threshold accompanied by insensitivity to punishment could be exacerbated by the hypodopaminergic tone in ADHD.

Increased cortical structural covariance correlates with anhedonia in schizophrenia

“…Previous positron emission tomography studies recruited healthy volunteers and showed that reward learning processes were correlated with dopamine in the mOFC and dorsal anterior cingulate cortex (ACC) 46 . Studies including attention deficit hyperactivity disorder or cocainedependent subjects also indicated that OFC dysfunction was related to altered dopamine function 47,48 .…”

Harm Avoidance is Correlated with the Reward System in Adult Patients with Attention Deficit Hyperactivity Disorder: A Functional Magnetic Resonance Imaging Study

“…After some prior scans, we determined that 3.5 minutes was a long enough duration in which to complete 10 trials. This procedure was as reported in our previous study [ 8 , 29 ].…”

“…Gambling or risky decision-making is related to the reward pathway, which is also an important biological characteristic among patients with ADHD. As several areas, and not only the insula, in this pathway may play a role, and may be correlated with harm avoidance [ 27 , 28 ], multiple regions of interest (ROIs) were probed in the present study [ 8 , 29 ]. The aim of this study was to probe the association between harm avoidance and brain activity in the reward system during winning and losing in a well-established task, the Iowa gambling task (IGT) [ 30 ], among adult patients with ADHD.…”