***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: Several variants in the methods used to estimate delay  discounting  ( DD ) have been associated with within-subject differences in degree of DD . This study compared variants in the order of presentation of reward and delay values during assessment of DD of hypothetical cash . Participants were r and omly assigned to one of two groups . For one group , the immediate reward values were presented in Ascending order and for the other , they were presented in Descending order . In addition , all participants completed a DD task with the reward values presented in a R and om order . Degree of DD , calculated as area under the curve ( AUC ) , was similar between the Ascending and Descending procedures , and was significantly higher with the R and om procedure . Within-subjects AUC were positively correlated . Reaction times within choice trials changed systematic ally as a function of order of presentation of the immediate rewards , and distance to the indifference point within each delay value . Reaction times appear to parallel the effort involved in making the individual choices . Some procedural variants in the assessment of DD yield differences in behavior during the assessment task that affect the magnitude of the estimated delay discounting . Thus , the absolute magnitude of DD may not be directly comparable between methods Background Alcohol consumption patterns change across life and this is not fully captured in cross-sectional series data . Analysis of longitudinal data , with repeat alcohol measures , is necessary to reveal changes within the same individuals as they age . Such data are scarce and few studies are able to capture multiple decades of the life course . Therefore , we examined alcohol consumption trajectories , reporting both average weekly volume and frequency , using data from cohorts with repeated measures that cover different and overlapping periods of life . Methods Data were from nine UK-based prospect i ve cohorts with at least three repeated alcohol consumption measures on individuals ( combined sample size of 59,397 with 174,666 alcohol observations ) , with data spanning from adolescence to very old age ( 90 years plus ) . Information on volume and frequency of drinking were harmonised across the cohorts . Predicted volume of alcohol by age was estimated using r and om effect multilevel models fitted to each cohort . Quadratic and cubic polynomial terms were used to describe non-linear age trajectories . Changes in drinking frequency by age were calculated from observed data within each cohort and then smoothed using locally weighted scatterplot smoothing . Models were fitted for men and women separately . Results We found that , for men , mean consumption rose sharply during adolescence , peaked at around 25 years at 20 units per week , and then declined and plateaued during mid-life , before declining from around 60 years . A similar trajectory was seen for women , but with lower overall consumption ( peak of around 7 to 8 units per week ) . Frequent drinking ( daily or most days of the week ) became more common during mid to older age , most notably among men , reaching above 50 % of men . Conclusions This is the first attempt to synthesis e longitudinal data on alcohol consumption from several overlapping cohorts to represent the entire life course and illustrates the importance of recognising that this behaviour is dynamic . The aetiological findings from epidemiological studies using just one exposure measure of alcohol , as is typically done , should be treated with caution . Having a better underst and ing of how drinking changes with age may help design intervention strategies Delay discounting was investigated in opioid-dependent and non-drug-using control participants . The latter participants were matched to the former on age , gender , education , and IQ . Participants in both groups chose between hypothetical monetary rewards available either immediately or after a delay . Delayed rewards were $ 1,000 , and the immediate-reward amount was adjusted until choices reflected indifference . This procedure was repeated at each of 7 delays ( 1 week to 25 years ) . Opioid-dependent participants were given a second series of choices between immediate and delayed heroin , using the same procedures ( i.e. , the amount of delayed heroin was that which could be purchased with $ 1,000 ) . Opioid-dependent participants  discounted delayed monetary rewards significantly more than did non-drug-using participants . Furthermore opioid-dependent participants discounted delayed heroin significantly more than delayed money Objective : The present study tested the extent to which age and obesity predicted impulsive choices for food and monetary outcomes and tested how a brief mindful-eating training would alter delay discounting for food and money choices compared with control groups . Method : First , 172 adolescents ( Mage = 13.13 years ) and 176 ( Mage = 23.33 years ) adults completed the Food Choice Question naire ( FCQ ) and Monetary Choice Question naire ( MCQ ) as measures of food and money delay discounting , respectively . Then , participants returned to the lab and were r and omly assigned to complete a brief mindful-eating training , watch a DVD on nutrition , or serve as a control . Participants completed the  FCQ  and  MCQ  again as a postmanipulation measure . Results : Participants with high percent body fat ( PBF ) were more impulsive for food than those with low PBF . Adults with high PBF were also more impulsive for money compared with adults with low PBF ; no PBF-related differences were found for adolescents . Participants in the mindful-eating group exhibited more self-controlled choices for food , but not for money . The control conditions did not exhibit changes . Conclusion : The study suggests that individuals with high PBF make more impulsive food choices relative to those with low PBF , which could increase the risk of obesity over time . It also is the first to demonstrate shifts in choice patterns for food and money using a brief mindful-eating training with adolescents . Mindful eating is a beneficial strategy to reduce impulsive food choice , at least temporarily , that may impede weight gain Increasing evidence supports the hypothesis that impulsive decision-making is a heritable risk factor for an alcohol use disorder ( AUD ) . Clearly identifying a link between impulsivity and AUD risk , however , is complicated by the fact that both AUDs and impulsivity are heterogeneous constructs . Underst and ing the link between the two requires identifying the underlying cognitive factors that lead to impulsive choices . Rodent models have established that a family history of excessive drinking can lead to the expression of a transgenerational impulsive phenotype , suggesting heritable alterations in the decision-making process . In the present study , we explored the cognitive processes underlying impulsive choice in a vali date d , selectively bred rodent model of excessive drinking — the alcohol-preferring ( “ P ” ) rat .  Impulsivity was measured via delay discounting ( DD ) , and P rats exhibited an impulsive phenotype as compared to their outbred foundation strain — Wistar rats .  Steeper discounting in P rats was associated with a lack of a prospect i ve behavioral strategy , which was observed in Wistar rats and was directly related to DD . To further explore the underlying cognitive factors mediating these observations , a drift diffusion model of DD was constructed . These simulations supported the hypothesis that prospect i ve memory of the delayed reward guided choice decisions , slowed discounting , and optimized the fit of the model to the experimental data . Collectively , these data suggest that a deficit in forming or maintaining a prospect i ve behavioral plan is a critical intermediary to delaying reward , and by extension , may underlie the inability to delay reward in those with increased AUD risk Obese individuals tend to behave more impulsively than healthy weight individuals across a variety of measures , but it is unclear whether this pattern can be altered . The present study examined the effects of a mindful eating behavioral strategy on impulsive and risky choice patterns for hypothetical food and money . In Experiment 1 , 304 participants completed computerized delay and probability discounting tasks  for food-related and monetary outcomes . High percent body fat ( PBF ) predicted more impulsive choice for food , but not small-value money , replicating previous work . In Experiment 2 , 102 r and omly selected participants from Experiment 1 were assigned to participate in a 50-min workshop on mindful eating or to watch an educational video . They then completed the discounting tasks again . Participants who completed the mindful eating session showed more self-controlled and less risk-averse discounting patterns for food compared to baseline ; those in the control condition discounted similarly to baseline rates . There were no changes in discounting for money for either group , suggesting stimulus specificity for food for the mindful eating condition OBJECTIVE A positive association between delay discounting and substance use has been documented ; substance users tend to discount future rewards more than non-users . However , studies detailing the responsiveness of delay discounting to interventions are lacking , and few have examined how any behavioral intervention affects delay discounting and whether these effects moderate changes in substance abuse . This study assesses the effectiveness of a money management intervention , Advisor-Teller Money Manager ( ATM ) , in reducing delay discounting over time and the relationship of these effects to changes in cocaine use . METHOD Ninety psychiatric patients with histories of cocaine and /or alcohol use were r and omly assigned to 36-weeks of ATM treatment or to a minimal-attention control condition .  Delay discounting and cocaine use were measured throughout the intervention with a 52-week follow up measure of cocaine use . Analyses were conducted of ( a ) the effect of ATM on slopes of delay discounting and cocaine abstinence and ( b ) the relationship between change in delay discounting and change in cocaine abstinence . RESULTS The ATM intervention was associated with significantly less delay discounting and less cocaine use over time relative to controls . Increases in delay discounting were associated with decreased abstinence from cocaine . CONCLUSIONS ATM treatment decreased delay discounting rates and these effects extended to cocaine use . Concrete conceptualizations of future events , as occur in financial planning , with higher perceived probability may account for higher valuation of future rewards in counseled patients A st and ard assumption in the delay discounting literature is that individuals who exhibit steeper discounting of hypothetical rewards also experience greater difficulty deferring gratification to real-world rewards . There is ample cross-sectional evidence that delay discounting paradigms reflect a variety of maladaptive psychosocial outcomes , including substance use pathology . We sought to determine whether a computerized assessment of hypothetical delay discounting ( HDD ) taps into behavioral impulsivity in a community sample of adolescent twins ( N = 675 ) . Using a longitudinal design , we hypothesized that greater HDD at age 14 - 15 predicts real-world impulsive choices and risk for substance use disorders in late adolescence . We also examined the genetic and environmental structure of HDD performance . Individual differences in HDD behavior showed moderate heritability , and were prospect ively associated with real-world temporal discounting at age 17 - 18 . Contrary to expectations , HDD was not consistently related to substance use or trait impulsivity . Although a significant association between HDD behavior and past substance use emerged in males , this effect was mediated by cognitive ability . In both sexes , HDD failed to predict a comprehensive index of substance use problems and behavioral disinhibition in late adolescence . In sum , we present some of the first evidence that HDD performance is heritable and predictive of real-world temporal discounting of rewards . Nevertheless , HDD might not serve as a valid marker of substance use disorder risk in younger adolescents , particularly females Fifty-six heroin addicts and 60 age-matched controls were offered choices between monetary rewards ( $ 11-$80 ) available immediately and larger rewards ( $ 25-$85 ) available after delays ranging from 1 week to 6 months . Participants had a 1-in-6 chance of winning a reward that they chose on one r and omly selected trial .  Delay-discounting rates were estimated from the pattern of participants ' choices . The discounting model of impulsiveness ( Ainslie , 1975 ) implies that delay-discounting rates are positively correlated with impulsiveness . On average , heroin addicts ' discount rates were twice those of controls ( p = .004 ) , and discount rates were positively correlated with impulsivity as measured by self-report question naires ( p < .05 ) . The results lend external validity to the  delay-discounting rate  as a measure of impulsiveness , a characteristic associated with substance abuse In this study , crack/cocaine-dependent ( CD ) and non-drug-using matched control ( MC ) participants were presented with hypothetical immediate and delayed rewards , with 16 delay conditions ranging from 5 min to 25 years . All participants were presented with hypothetical monetary rewards ; however , the CD group was also presented with hypothetical crack/cocaine rewards . The objective value of the rewards ranged from $ 1 to $ 1,000 . Hyperbolic discounting functions provided a good fit of the data . The CD group discounted monetary rewards at a higher rate than the MC group did , and the CD group discounted crack/cocaine rewards at a higher rate than it did monetary rewards . Moreover , scores on self-report measures indicated greater impulsivity in the CD group when compared with the MC group Behavioral measures of impulsivity are widely used in substance abuse research , yet relatively little attention has been devoted to establishing their psychometric properties , especially their reliability over repeated administration . The current study examined the test-retest reliability of a battery of st and ardized behavioral impulsivity tasks , including measures of impulsive choice ( i.e. , delay discounting , probability discounting , and the Balloon Analogue Risk Task ) , impulsive action ( i.e. , the stop signal task , the go/no-go task , and commission errors on the continuous performance task ) , and inattention ( i.e. , attention lapses on a simple reaction time task and omission errors on the continuous performance task ) . Healthy adults ( n = 128 ) performed the battery on two separate occasions . Reliability estimates for the individual tasks ranged from moderate to high , with Pearson correlations within the specific impulsivity domains as follows : impulsive choice ( r range : .76-.89 , ps < .001 
    Output:
    
We found overwhelming evidence for the state-like quality of  delay discounting :  Consistent with Petry and others ' work , nonmonetary outcomes are discounted more steeply than monetary outcomes .
We propose two hypotheses that together may account for this effect : Decreasing Future Preference and Decreasing Future Worth .
We also found clear evidence that  delay discounting  has trait-like qualities : People who steeply discount monetary outcomes steeply discount nonmonetary outcomes as well .
The implication is that changing  delay discounting  for one outcome could change discounting for other outcomes