***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: 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 The choice of small immediate rewards as opposed to larger delayed rewards , or delay discounting , is an important dimension of impulsive decision making . The inability to delay gratification is related to obesity , as well as other maladaptive behaviors such as substance abuse , problem drinking , smoking , pathological gambling , and risky HIV behaviors . One way to reduce delay discounting ( DD ) may be to use prospect i ve imagery in the form of episodic future thinking ( EFT ) during inter-temporal decision making . We have recently shown that EFT reduces DD and ad libitum energy intake in obese individuals . However , no studies have examined whether the magnitude of the EFT effect differs between lean and overweight/obese individuals . We conducted a within-subject design experiment to compare the efficacy of EFT versus a control task in reducing DD between lean ( N=24 ) and overweight/obese ( N=24 ) women . Participants attended two sessions in which they engaged in either EFT or control episodic thinking during a DD task . We also examined whether individual differences such as trait time perspective , behavioral inhibition or behavioral activation moderated the EFT effect on DD . Results showed EFT  reduced DD similarly for lean and overweight/obese individuals . The EFT effect was moderated by behavioral activation . This suggests EFT is just as effective in reducing impulsive decision making in obese individuals as it is in lean individuals and may be useful in reducing other impulsive obesity related behaviors Binge eating is often preceded by reports of negative affect , but the mechanism by which affect may lead to binge eating is unclear . This study evaluated the effect of negative affect on neural response to anticipation and receipt of palatable food in women with bulimia nervosa ( BN ) versus healthy controls . We also evaluated connectivity between the amygdala and reward-related brain regions . Females with and without BN ( n=26 ) underwent functional magnetic resonance imaging ( fMRI ) during receipt and anticipated receipt of chocolate milkshake and a tasteless solution . We measured negative affect just prior to the scan . Women with BN showed a positive correlation between negative affect and activity in the putamen , cau date , and pallidum during anticipated receipt of milkshake ( versus tasteless solution ) . There were no significant relations between negative affect and receipt of milkshake . Connectivity analyses revealed a greater relation of amygdala activity to activation in the left putamen and insula during anticipated receipt of milkshake in the bulimia group relative to the control group . The opposite pattern was found for the taste of milkshake ; the control group showed a greater relation of amygdala activity to activation in the left putamen and insula in response to milkshake receipt than the bulimia group . Results show that as negative affect increases , so does responsivity of reward regions to anticipated intake of palatable food , implying that negative affect may increase the reward value of food for individuals with bulimia nervosa or that negative affect has become a conditioned cue due to a history of binge eating in a negative mood Disturbances in reward processing have been implicated in bulimia nervosa ( BN ) . Abnormalities in processing reward-related stimuli might be linked to dysfunctions of the catecholaminergic neurotransmitter system , but findings have been inconclusive . A powerful way to investigate the relationship between catecholaminergic function and behavior is to examine behavioral changes in response to experimental catecholamine depletion ( CD ) . The purpose of this study was to uncover putative catecholaminergic dysfunction in remitted subjects with BN who performed a reinforcement-learning task after CD . CD was achieved by oral alpha-methyl-para-tyrosine ( AMPT ) in  19 unmedicated female subjects with remitted BN ( rBN ) and 28 demographically matched healthy female controls ( HC ) .  Sham depletion administered identical capsules containing diphenhydramine . The study design consisted of a r and omized , double-blind , placebo-controlled crossover , single-site experimental trial . The main outcome measures were reward learning in a probabilistic reward task analyzed using signal-detection theory . Secondary outcome measures included self-report assessment s , including the Eating Disorder Examination- Question naire . Relative to healthy controls , rBN subjects were characterized by blunted reward learning in the AMPT — but not in placebo — condition . Highlighting the specificity of these findings , groups did not differ in their ability to perceptually distinguish between stimuli . Increased  CD-induced anhedonic ( but not eating disorder ) symptoms were associated with a reduced response bias toward a more frequently rewarded stimulus . In conclusion , under CD , rBN subjects showed reduced reward learning compared with healthy control subjects . These deficits uncover disturbance of the central reward processing systems in rBN related to altered brain catecholamine levels , which might reflect a trait-like deficit increasing vulnerability to BN OBJECTIVE To identify shared risk and protective factors for purging , binge eating , and overweight . DESIGN Prospect i ve cohort study . SETTING Population -based question naires of children and adolescents residing across the United States . PARTICIPANTS Girls ( n = 6022 ) and boys ( n = 4518 ) , aged 11 to 17 years in 1998 , in the ongoing Growing Up Today Study . MAIN EXPOSURES Putative risk and protective factors within the psychological , behavioral , and socioenvironmental domains . MAIN OUTCOME MEASURES Overweight , use of laxatives or purging ( vomiting ) , and binge eating . Because of the low prevalence of purging , we did not examine shared factors for this behavior among boys . RESULTS In 1998 , a total of 219 girls ( 3.7 % ) and 30 boys ( 0.7 % ) reported purging behaviors , 426 girls ( 7.1 % ) and 90 boys ( 2.0 % ) reported binge eating , and 1019 girls ( 17.4 % ) and 1040 boys ( 24.6 % ) were overweight . From 1999 through 2001 , 331 girls ( 7.8 % ) initiated purging behaviors , 503 girls ( 11.8 % ) and 132 boys ( 4.5 % ) initiated binge eating behaviors , and 424 girls ( 10.0 % ) and 382 boys ( 13.6 % ) became overweight . Concern for weight was directly associated with all 3 weight-related problems among boys and girls . Among girls , dieting , parental weight-related teasing , and family meal frequency had a shared effect on the weight-related problems examined . CONCLUSIONS Factors within the psychological , behavioral , and socioenvironmental domains may have a shared effect on purging , binge eating , and overweight . Further research is needed to determine if an intervention design ed to address these shared risk and protective factors is effective in simultaneously reducing these weight-related problems BACKGROUND Obesity is among the leading causes of disease and death . Bariatric surgery is the most effective treatment of obesity . There is increasing evidence that after gastric bypass surgery , patients and animal models show a decreased preference for sweet and fatty foods . The underlying mechanism may include alterations in taste function . OBJECTIVE We hypothesize that a gastric bypass reduces the reward value of sweet and fat tastes . DESIGN In this prospect i ve case-control study , 11 obese patients who were scheduled to undergo a gastric bypass and 11 normal-weight control subjects in the fed state  clicked a computer mouse to receive a sweet and fatty c and y on a progressive ratio schedule 10 wk apart ( in patients , testing took place 2 wk before and 8 wk after gastric bypass surgery ) . Subjects worked progressively harder to obtain a food reward ( reinforcer ) until they stopped clicking ( ie , the breakpoint ) , which was a measure of the reinforcer value . Breakpoints were assessed by the number of mouse clicks in the last completed ratio . The experiment was repeated in a different cohort by using vegetable pieces as the reinforcer . RESULTS Breakpoints in the test sessions of control subjects correlated highly for both reinforcers . The median breakpoint for c and ies , but not vegetables , was reduced by 50 % in the obese group after gastric bypass . Patients with the largest reduction in the breakpoint had the largest decrease in BMI . CONCLUSIONS Gastric bypass surgery result ed in the selective reduction of the reward value of a sweet and fat tastant . This application of the progressive ratio task provided an objective and reliable evaluation of taste-driven motivated behavior for food stimuli after obesity surgery Obesity and cigarette smoking are often cited separately as the top two preventable causes of death in the United States ; however , little research has explored the factors associated with being both obese and a smoker . Delay discounting is a behavioral characteristic that may underlie both of these conditions/behaviors . Delay discounting describes the extent to which an individual discounts the value of an outcome because of a delay in its occurrence . Higher rates of discounting are often considered as an index of impulsivity and have been linked with obesity and cigarette smoking . No research to date has explored  delay discounting  in a sample of obese smokers . For this study , adolescent smokers classified as obese ( body mass index > 95th percentile ) and healthy weight ( body mass index between the 5th and 85th percentiles ) were compared on a laboratory assessment of delay discounting .  Obese smokers  discounted significantly more by delay than healthy weight smokers . This difference remained statistically significant even after controlling for demographic variables that differed across groups . These findings suggest that the relationships between  delay discounting and obesity and cigarette smoking may be additive , such that extreme discounting might proportionally increase the risk of becoming an obese smoker . However , future prospect i ve study is needed to fully determine the veracity of this hypothesis Binge eating is a core clinical feature of bulimia nervosa ( BN ) . Enhanced reinforcing value of food may play a role in this behavioral disturbance , but a systematic behavioral assessment of objective measures of the rewarding value of binge eating is lacking . The purpose of this study was to quantify the reinforcing value of food in BN patients as compared with normal controls . A progressive ratio ( PR ) computerized work task was completed under binge and non-binge instruction . The task consisted of 12 trials . The first trial required 50 keyboard taps to earn one portion of yogurt shake , and subsequent trials required progressive work increments of 200 taps for each additional portion . Completion of all 12 trials required 13,800 taps to earn 2100ml of shake . The breakpoint , defined as the largest ratio completed before a participant stopped working , was the measure of reinforcing efficacy . Ten patients and 10 controls completed the experiment . Under binge instruction , patients completed more trials and taps , and had a higher breakpoint than controls . The non-binge instruction yielded opposite findings ; compared to controls , patients completed fewer trials and taps , and had a lower breakpoint . These results support the feasibility and potential utility of a PR task to quantify the reinforcing value of food in patients with BN OBJECTIVE There are limited data supporting specific treatments for adults with anorexia nervosa ( AN ) . R and omized clinical trials ( RCTs ) for adults with AN are characterized by high attrition limiting the feasibility of conducting and interpreting existing studies . High dropout rates may be related to the inflexible and obsessional cognitive style of patients with AN . This study evaluated the feasibility of using cognitive remediation therapy ( CRT ) to reduce attrition in RCTs for AN . METHOD Forty-six participants ( mean age of 22.7 years and mean duration of AN of 6.4 years ) were r and omized to receive eight sessions of either CRT or cognitive behavioral therapy ( CBT ) over 2 months followed by 16 sessions of CBT for 4 months . RESULTS During the 2-month CRT vs. CBT  treatment , rates of attrition were lower in CRT ( 13 % ) compared with that of CBT ( 33 % ) . There were greater improvements in cognitive inefficiencies in the CRT compared with that of the CBT group at the end of 2 months . There were no differences in other outcomes . DISCUSSION These results suggest that CRT is acceptable and feasible for use in RCTs for outpatient treatment of AN . CRT may reduce attrition in the short term . Adequately powered future studies are needed to examine CRT as an outpatient treatment for AN Background : Individuals with eating disorders show deficits in neuropsychological functioning which might preexist and underlie the etiology of the eating disorders and influence relapse . Deficits in cognitive flexibility , i.e. set-shifting and central coherence , might perpetuate the symptoms . Cognitive remediation therapy ( CRT ) was developed to improve cognitive flexibility , thereby increasing the likelihood of improved outcome . The focus of CRT is on how patients think , rather than on what patients think . The present study investigated the effectiveness of  CRT  for patients with a severe or enduring eating disorder by means of a 
    Output:
    
Decision making was found to be altered to similar degrees in all ED subtypes and OB .
Effect sizes , however , diverged for the different measures of decision making .
Adolescents appear to be less affected than adults .
When foods were used as rewarding stimuli , decision making was found to be intact in OB .
The findings support that altered general reward-related decision making is a salient neuropsychological factor across eating and weight disorders in adulthood