***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Impulsive delayed reward discounting ( DRD ) is an important behavioral process in alcohol use disorders ( AUDs ) , reflecting incapacity to delay gratification . Recent work in neuroeconomics has begun to unravel the neural mechanisms supporting DRD , but applications of neuroeconomics in relation to AUDs have been limited . This study examined the neural mechanisms of DRD preferences in AUDs , with emphasis on dissociating activation patterns based on DRD choice type and level of cognitive conflict . Heavy drinking adult men with ( n = 13 ) and without ( n = 12 ) a diagnosis of an AUD completed a monetary DRD task during a functional magnetic resonance imaging scan . Participant responses were coded based on choice type ( impulsive versus restrained ) and level of cognitive conflict ( easy versus hard ) . AUD+ participants exhibited significantly more impulsive DRD decision‐making . Significant activation during DRD was found in several decision‐making regions , including dorsolateral prefrontal cortex ( DLPFC ) , insula , posterior parietal cortex ( PPC ) , and posterior cingulate . An axis of cognitive conflict was also observed , with hard choices associated with anterior cingulate cortex and easy choices associated with activation in supplementary motor area . AUD+ individuals exhibited significant hyperactivity in regions associated with cognitive control ( DLPFC ) and prospect i ve thought ( PPC ) and exhibited less task‐related deactivation of areas associated with the brain 's default network during DRD decisions . This study provides further clarification of the brain systems supporting DRD in general and in relation to AUDs Failures of self-regulation in problem and pathological gambling ( PPG ) are thought to emerge from failures of top-down control , reflected neurophysiologically in a reduced capacity of prefrontal cortex to influence activity within subcortical structures . In patients with addictions , these impairments have been argued to alter evaluation of reward within dopaminergic neuromodulatory systems . Previously we demonstrated that augmenting dopamine tone in frontal cortex via use of tolcapone , an inhibitor of the dopamine-degrading enzyme catechol-O-methyltransferase ( COMT ) , reduced delay discounting , a measure of impulsivity , in healthy subjects . To evaluate this potentially translational approach to augmenting prefrontal inhibitory control , here we hypothesized that increasing cortical dopamine tone would reduce delay discounting in PPG subjects in proportion to its ability to augment top-down control . To causally test this hypothesis , we administered the COMT inhibitor tolcapone in a r and omized , double-blind , placebo-controlled , within-subject study of 17 PPG subjects who performed a delay discounting task while functional MRI images were obtained . In this subject population , we found that greater BOLD activity during the placebo condition within the right inferior frontal cortex ( RIFC ) , a region thought to be important for inhibitory control , correlated with greater declines in impulsivity on tolcapone versus placebo . Intriguingly , connectivity between RIFC and the right striatum , and not the level of activity within RIFC itself , increased on tolcapone versus placebo . Together , these findings support the hypothesis that tolcapone-mediated increases in top-down control may reduce impulsivity in PPG subjects , a finding with potential translational relevance for gambling disorders , and for behavioral addictions in general A prospect i ve , behavioral high-risk design provided a theoretically guided examination of vulnerability to first onset of bipolar spectrum disorder based on the Behavioral Approach System ( BAS ) model . Adolescents ( ages 14 - 19 ) at an " age of risk " for bipolar disorder onset were screened on BAS sensitivity by interviewers blind to current symptoms , lifetime history , and family history of psychopathology . Participants were selected with high versus moderate levels of BAS sensitivity and administered a lifetime diagnostic interview . Those with a bipolar spectrum disorder , psychosis , or hypomanic episode with onset prior to the BAS sensitivity assessment were excluded . High BAS ( n = 171 ) and moderate BAS ( n = 119 ) sensitivity participants in the final sample completed baseline measures of symptoms , goal - setting , and reward responsiveness and were followed prospect ively with semistructured diagnostic interviews every 6 months . Consistent with the vulnerability hypothesis of the BAS model of bipolar disorder , high BAS participants had a greater likelihood , and shorter time to onset , of bipolar spectrum disorder than moderate BAS participants across an average of 12.8 months of follow-up ( 12.9 % vs. 4.2 % ) , controlling for baseline depressive and hypomanic symptoms , and family history of bipolar disorder . High reward responsiveness on a behavioral task and ambitious goal -striving for popular fame and financial success ( but not impulsivity ) also predicted first onset of bipolar spectrum disorder controlling for the covariates and BAS risk group , and ambitious goal -striving partially mediated the BAS risk group effect . We discuss implication s of the findings for the BAS model of bipolar disorder and early intervention efforts Generally , rewards that are received sooner are often preferred over future rewards , and the time between the choice and the reception of the reward is an important factor that influences our decisions , a phenomenon called delay discounting ( DD ) . In DD , the medial prefrontal cortex ( MePFC ) and striatal dopamine neurotransmission both play an important role . We used repetitive transcranial magnetic stimulation ( rTMS ) to transiently activate the MePFC to evaluate its behavioral effect on the DD paradigm , and subsequently to measure its effect on striatal dopamine .  Twenty-four right-h and ed young healthy subjects ( 11 females ; age : 22.1±2.9 years ) underwent DD following 10 Hz-rTMS of the MePFC and vertex stimulation ( control condition ) . Thereafter , 11 subjects ( 5 females ; age : 22.2±2.87 years ) completed the PET study at rest using [11C]-(+)-PHNO following 10 Hz-rTMS of the MePFC and vertex . Modulation of the MePFC excitability influenced the subjective level of DD for delayed rewards and interfered with synaptic dopamine level in the striatum . The present study yielded findings that might reconcile the role of these areas in inter-temporal decision making and dopamine modulation , suggesting that the subjective sense of time and value of reward are critically controlled by these important regions 
    Output:
    
The present review revealed that greater DD was correlated with increased activity in areas related to reward evaluation and prediction as well as decreased activity in areas related to cognitive control .
Healthy controls showed smaller changes in activities of these areas associated with DD when compared to patient groups .
This review generated consistent findings on the neural basis of DD among patients with addiction and psychiatric disorders , which may represent the pathophysiology related to DD and impulsivity of mental illness