Neuroeconomics and adolescent substance abuse: individual differences in neural networks and delay discounting

Associations Between Family History of Alcohol and/or Substance Use Problems and Frontal Cortical Development From 9 to 13 Years of Age: A Longitudinal Analysis of the ABCD Study

Background

Previous investigations that have examined associations between family history (FH) of alcohol/substance use and adolescent brain development have been primarily cross-sectional. Here, leveraging a large population-based sample of youths, we characterized frontal cortical trajectories among 9- to 13-year-olds with (FH+) versus without (FH-) an FH and examined sex as a potential moderator.

Methods

We used data from 9710 participants in the Adolescent Brain Cognitive Development (ABCD) Study (release 4.0). FH+ was defined as having ≥1 biological parents and/or ≥2 biological grandparents with a history of alcohol/substance use problems (n = 2433). Our primary outcome was frontal cortical structural measures obtained at baseline (ages 9-11) and year 2 follow-up (ages 11-13). We used linear mixed-effects models to examine the extent to which FH status qualified frontal cortical development over the age span studied. Finally, we ran additional interactions with sex to test whether observed associations between FH and cortical development differed significantly between sexes.

Results

For FH+ (vs. FH-) youths, we observed increased cortical thinning from 9 to 13 years across the frontal cortex as a whole. When we probed for sex differences, we observed significant declines in frontal cortical thickness among boys but not girls from ages 9 to 13 years. No associations were observed between FH and frontal cortical surface area or volume.

Conclusions

Having a FH+ is associated with more rapid thinning of the frontal cortex across ages 9 to 13, with this effect driven primarily by male participants. Future studies will need to test whether the observed pattern of accelerated thinning predicts future substance use outcomes.

Spontaneous neural activity in the three principal networks underlying delay discounting: a resting-state fMRI study

Delay discounting, the decline in the subjective value of future rewards over time, has traditionally been understood through a tripartite neural network model, comprising the valuation, cognitive control, and prospection networks. To investigate the applicability of this model in a resting-state context, we employed a monetary choice questionnaire to quantify delay discounting and utilized resting-state functional magnetic resonance imaging (rs-fMRI) to explore the role of spontaneous brain activity, specifically regional homogeneity (ReHo), in influencing individual differences in delay discounting across a large cohort (N = 257). Preliminary analyses revealed a significant negative correlation between delay discounting tendencies and the ReHo in both the left insula and the right hippocampus, respectively. Subsequent resting-state functional connectivity (RSFC) analyses, using these regions as seed ROIs, disclosed that all implicated brain regions conform to the three principal networks traditionally associated with delay discounting. Our findings offer novel insights into the role of spontaneous neural activity in shaping individual variations in delay discounting at both regional and network levels, providing the first empirical evidence supporting the applicability of the tripartite network model in a resting-state context.

Assessing the utility of a novel cortical marker of delay discounting (C-DD) in two independent samples of early adolescents: Links with externalizing pathology

Delay discounting is a well-established risk factor for risky behaviors and the development of externalizing spectrum disorders. Building upon recent work that developed a novel cortical marker of delay discounting (C-DD) in adult samples, the objective of this study was to test whether the C-DD relates to delay discounting and subsequently externalizing pathology in adolescent samples. The current study used two samples: 9992 early adolescents participating in the ABCD study (Mage = 9.93 years old, 48.7% female), and 56 early adolescents recruited from the community (Mage = 12.27 years old, 55.4% female). Cortical thickness was estimated using the FreeSurfer standard pipeline, and the cortical marker of delay discounting (C-DD) was calculated based on procedures outlined by the initial validation study. All data are cross-sectional in nature. As expected, C-DD was positively related to delay discounting in the ABCD sample, even after accounting for age, biological sex, collection site and data quality indicators. Moreover, results showed that C-DD was discriminately associated with externalizing, but not internalizing, symptoms in both samples of young adolescents. Findings replicate those found in adult samples, suggestive that C-DD may be a useful neuroanatomical marker of youth delay discounting. Replication of findings in other samples will be needed to determine whether C-DD has translational relevance to understanding externalizing psychopathology in adolescent samples.

Examining the relationship of concurrent obesity and tobacco use disorder on the development of substance use disorders and psychiatric conditions: Findings from the NESARC-III

Background

Multimorbidity is linked to worse health outcomes than single health conditions. However, recent studies show that obesity may reduce the risk of developing substance use disorders (SUDs), particularly in vulnerable populations. We investigated how comorbid obesity and tobacco use disorder (TUD) relate to the risk of SUDs and psychiatric conditions.

Methods

Data was used from 36,309 individuals who completed the National Epidemiological Survey on Alcohol and Related Conditions - Wave III. Individuals who met the DSM-5 criteria for TUD in the last year were defined as the TUD group. Obesity was defined as having a body mass index (BMI) greater than 30 kg/m2. Using this information, individuals were grouped into categories, with people being identified as either having obesity, TUD, both obesity and TUD, or not having either obesity or TUD (comparison). Groups were compared against their comorbid diagnoses of either an additional SUD or psychiatric conditions.

Results

Controlling for demographic characteristics, we found that individuals with obesity including those individuals with TUD, had lower rates of comorbid SUD diagnosis than individuals with TUD alone. Additionally, individuals with combined TUD and obesity, and those with TUD alone, had the highest rates of comorbid psychiatric disorder diagnosis.

Conclusions

The current study aligns with previous research suggesting that obesity may reduce risk of substance use disorders, even in individuals who have other risk factors promoting harmful substance use (e.g., tobacco use). These findings may inform targeted intervention strategies for this clinically relevant subpopulation.

An altered reward system characterizes chronic migraine with medication overuse headache

BACKGROUND

Medication overuse headache shares several characteristics with substance use disorders. However, key features of substance use disorders such as increased impulsivity and alterations in reward processing remain little explored in medication overuse headache.

METHODS

Temporal discounting and impulsive decision making behavior and the associated brain mechanisms were assessed in 26 chronic migraine patients with medication overuse headache and in 28 healthy controls. Regions-of-interest analyses were first performed for task-related regions, namely the ventral striatum and the ventromedial and dorsomedial prefrontal cortices. Resting-state functional connectivity between these regions were then explored. An additional 27 chronic migraine patients without medication overuse headache were included for comparison in the latter analysis.

RESULTS

Patients with medication overuse headache showed steeper temporal discounting behavior than healthy controls. They also showed weaker subjective value representations in the dorsomedial prefrontal cortex, when accepting larger delayed rewards, and in ventral striatum and ventromedial prefrontal cortex, when accepting the smaller immediate reward. Resting-state functional connectivity was reduced among the valuation regions when comparing patients with medication overuse headache to the other two control groups.

CONCLUSIONS

Patients with medication overuse headache were characterized by altered processing and dysconnectivity in the reward system during intertemporal choices and in the resting-state.

Temporal discounting for self and friends in adolescence: A fMRI study

Adolescence is characterized by impulsivity but also by increased importance of friendships. This study took the novel perspective of testing temporal discounting in a fMRI task where choices could affect outcomes for 96 adolescents (aged 10-20-years) themselves and their best friend. Decisions either benefitted themselves (i.e., the Self Immediate - Self Delay' condition) or their friend (i.e., 'Friend Immediate - Friend Delay' condition); or juxtaposed rewards for themselves and their friends (i.e., the 'Self Immediate - Friend Delay' or 'Friend Immediate - Self Delay' conditions). We observed that younger adolescents were more impulsive; and all participants were more impulsive when this was associated with an immediate benefit for friends. Individual differences analyses revealed increased activity in the subgenual anterior cingulate cortex extending in the ventral striatum for immediate relative to delayed reward choices for self. Temporal choices were associated with activity in the prefrontal cortex, parietal cortex, insula, and ventral striatum, but only activity in the right inferior parietal lobe was associated with age. Finally, temporal delay choices for friends relative to self were associated with increased activity in the temporo-parietal junction and precuneus. Overall, this study shows a unique role of the social context in adolescents' temporal decision making.

Developmental trajectories of delay discounting from childhood to young adulthood: longitudinal associations and test-retest reliability

Delay discounting (DD) indexes an individual's preference for smaller immediate rewards over larger delayed rewards, and is considered a form of cognitive impulsivity. Cross-sectional studies have demonstrated that DD peaks in adolescence; longitudinal studies are needed to validate this putative developmental trend, and to determine whether DD assesses a temporary state, or reflects a more stable behavioral trait. In this study, 140 individuals aged 9-23 completed a delay discounting (DD) task and cognitive battery at baseline and every-two years thereafter, yielding five assessments over approximately 10 years. Models fit with the inverse effect of age best approximated the longitudinal trajectory of two DD measures, hyperbolic discounting (log[k]) and area under the indifference-point curve (AUC). Discounting of future rewards increased rapidly from childhood to adolescence and appeared to plateau in late adolescence for both models of DD. Participants with greater verbal intelligence and working memory displayed reduced DD across the duration of the study, suggesting a functional interrelationship between these domains and DD from early adolescence to adulthood. Furthermore, AUC demonstrated good to excellent reliability across assessment points that was superior to log(k), with both measures demonstrating acceptable stability once participants reached late adolescence. The developmental trajectories of DD we observed from childhood through young adulthood suggest that DD may index cognitive control more than reward sensitivity, and that despite modest developmental changes with maturation, AUC may be conceptualized as a trait variable related to cognitive control vs impulsivity.

The Resting-State Neural Network of Delay Discounting

Delay discounting is a common phenomenon in daily life, which refers to the subjective value of a future reward decreasing as a function of time. Previous studies have identified several cortical regions involved in delay discounting, but the neural network constructed by the cortical regions of delay discounting is less clear. In this study, we employed resting-state functional magnetic resonance imaging (RS-fMRI) to measure the spontaneous neural activity in a large sample of healthy young adults and used the Monetary Choice Questionnaire to directly measure participants’ level of delay discounting. To identify the neural network of delay discounting at rest, we used an individual difference approach to explore brain regions whose spontaneous activities were related to delay discounting across the whole brain. Then, these brain regions served as seeds to identify the neural network of delay discounting. We found that the fractional amplitude of low-frequency fluctuations (fALFF) of the left insula were positively correlated to delay discounting. More importantly, its connectivity to the anterior cingulate cortex was read out for participants’ behavioral performance in the task of delay discounting. In short, our study provides empirical evidence that insula-anterior cingulate cortex connectivity may serve as a part of the neural network for delay discounting.

Deprivation Has Inconsistent Effects on Delay Discounting: A Review

Delay discounting, the tendency for outcomes to be devalued as they are more temporally remote, has implications as a target for behavioral interventions. Because of these implications, it is important to understand how different states individuals may face, such as deprivation, influence the degree of delay discounting. Both dual systems models and state-trait views of delay discounting assume that deprivation may result in steeper delay discounting. Despite early inconsistencies and mixed results, researchers have sometimes asserted that deprivation increases delay discounting, with few qualifications. The aim of this review was to determine what empirical effect, if any, deprivation has on delay discounting. We considered many kinds of deprivation, such as deprivation from sleep, drugs, and food in humans and non-human animals. For 23 studies, we analyzed the effect of deprivation on delay discounting by computing effect sizes for the difference between delay discounting in a control, or baseline, condition and delay discounting in a deprived state. We discuss these 23 studies and other relevant studies found in our search in a narrative review. Overall, we found mixed effects of deprivation on delay discounting. The effect may depend on what type of deprivation participants faced. Effect sizes for deprivation types ranged from small for sleep deprivation (Hedge's gs between −0.21 and 0.07) to large for opiate deprivation (Hedge's gs between 0.42 and 1.72). We discuss possible reasons why the effect of deprivation on delay discounting may depend on deprivation type, including the use of imagined manipulations and deprivation intensity. The inconsistency in results across studies, even when comparing within the same type of deprivation, indicates that more experiments are needed to reach a consensus on the effects of deprivation on delay discounting. A basic understanding of how states affect delay discounting may inform translational efforts.

P300 and delay-discounting in obsessive-compulsive disorder

Previous research showed that dysfunctions of fronto-striatal neural networks are implicated in the pathophysiology of obsessive-compulsive disorder (OCD). Accordingly, patients with OCD showed altered performances during decision-making tasks. As P300, evoked by oddball paradigms, is suggested to be related to attentional and cognitive processes and generated in the medial temporal lobe and orbitofrontal and cingulate cortices, it is of special interest in OCD research. Therefore, this study aimed to investigate P300 in OCD and its associations with brain activity during decision-making: P300, evoked by an auditory oddball paradigm, was analysed in 19 OCD patients and 19 healthy controls regarding peak latency, amplitude and source density power in parietal cortex areas by sLORETA. Afterwards, using a fMRI paradigm, Blood-oxygen-level-dependent (BOLD) contrast imaging was conducted during a delay-discounting paradigm. We hypothesised differences between groups regarding P300 characteristics and associations with frontal activity during delay-discounting. The P300 did not differ between groups, however, the P300 latency over the P4 electrode correlated negatively with the NEO-FFI score openness to experience in patients with OCD. In healthy controls, P300 source density power correlated with activity in frontal regions when processing rewards, a finding which was absent in OCD patients. To conclude, associations of P300 with frontal brain activation during delay-discounting were found, suggesting a contribution of attentional or context updating processes. Since this association was absent in patients with OCD, the findings could be interpreted as being indeed related to dysfunctions of fronto-striatal neural networks in patients with OCD.

OUP accepted manuscript

The Coronavirus disease of 2019 (COVID-19) and measures to curb it created population-level changes in male-dominant impulsive and risky behaviors such as violent crimes and gambling. One possible explanation for this is that the pandemic has been stressful, and males, more so than females, tend to respond to stress by altering their focus on immediate versus delayed rewards, as reflected in their delay discounting rates. Delay discounting rates from healthy undergraduate students were collected twice during the pandemic. Discounting rates of males (n=190) but not of females (n=493) increased during the pandemic. Using machine learning, we show that prepandemic functional connectome predict increased discounting rates in males (n=88). Moreover, considering that delay discounting is associated with multiple psychiatric disorders, we found the same neural pattern that predicted increased discounting rates in this study, in secondary datasets of patients with major depression and schizophrenia. The findings point to sex-based differences in maladaptive delay discounting under real-world stress events, and to connectome-based neuromarkers of such effects. They can explain why there was a population-level increase in several impulsive and risky behaviors during the pandemic and point to intriguing questions about the shared underlying mechanisms of stress responses, psychiatric disorders and delay discounting.

Randomized Controlled Trial of an Alcohol-related Sexual Risk Reduction Intervention with Adolescents: The Role of Neurocognitive Activation During Risky Decision-Making

Justice-involved youth are at a higher risk of negative outcomes from sexual activity and alcohol use relative to their non-justice involved peers. In the current study, we tested the extent to which variability in neurocognitive response (i.e., activation in the right superior parietal lobule; rSPL) during a risky decision-making task moderated the success of a sexual risk reduction intervention. In a cluster randomized trial blocked by gender, justice-involved adolescents (N = 269) first completed a risky decision-making task during a magnetic resonance imaging (MRI) session, then were assigned to an information-only control (GINFO) or sexual risk reduction intervention incorporating alcohol risk reduction content (GPI + GMET) and then re-contacted every three months for one year. Youth in the GPI + GMET intervention reported less sexual risk behavior 12 months after intervention than those in the control. Although neurocognitive activation was associated with sexual risk behavior, it did not moderate intervention outcomes. This risk-reduction intervention appears to work equally well across a range of neurocognitive responses.

Integrating Objective and Subjective Social Class to Advance Our Understanding of Externalizing Problem Behavior in Children and Adolescents: A Conceptual Review and Model

Extant research has identified both objective measures of socioeconomic status (SES) and subjective social class (SSC) as important predictors of psychosocial outcomes in childhood and adolescence, particularly with regard to externalizing symptoms. Given the importance of the associations with SES and SSC, a more nuanced and integrated conceptual understanding of early pathways of vulnerability implicated in the development and maintenance of youth externalizing problems is warranted. Thus, this review will: (1) operationalize both SES and SSC and their current standards of measurement; (2) examine current literature describing their respective associations with a range of externalizing symptoms in both children and adolescents; (3) review current theoretical models connecting SES and SSC and youth development and the strengths and limitations of those approaches; (4) propose a new conceptual socioecological model situating the impact of SES and SSC on youth externalizing problems in the context of parents and peers as a framework to further integrate existing research and guide future work; and (5) discuss potential clinical implications at the intersection of this work.

Neural networks during delay discounting as trans-disease marker: A meta-analytical review

Delay discounting reflects a devaluation of delayed long-term benefits but pursuing immediate rewards. Higher discounting rates (h-DR) are found ubiquitous in many diseases and unhealthy conditions, particularly in addiction disorder (AD), attention-deficit/hyperactivity disorder (ADHD), and obesity. Thus, h-DR was considered to be a common benchmark across many diseases facilitating to understand one disease to relevant others, which was called trans-disease process. However, the common and specific neural biomarkers associated with this process has not yet been studied well. We performed a voxel-wise task-related neuroimaging meta-analysis to clarify the neural pattern of trans-disease process across AD, ADHD and obesity. We recruited 19 eligible papers, including 9 AD papers (154 patients), 6 ADHD papers (106 patients) and 4 obesity studies (94 patients). Neuroimaging meta-analysis demonstrated the presence of neural biomarkers of trans-disease process: these patients showed inadequate brain response in caudate, ventromedial and dorsolateral prefrontal cortex (dlPFC) than do of healthy controls (HCs). Disease-specific neural patterns were also found, with prominent hypoactivation in parahippocampal-striatum network for AD, hyperactivation in dopamine-projection striatum network for ADHD and decreased activity in dorsal anterior cingulate cortex and dlPFC for obesity. This study provided robust evidence to reveal the neural substrates of trans-disease process, as well further promoted the triple brain network model in favor of the theoretical developments of these neuropsychiatric disorders.

The neurodevelopment of delay discounting for monetary rewards in pre-adolescent children

Children are found to exhibit high degrees of delay discounting compared with adults in many delay discounting studies, which might be due to the asynchronous development of "bottom-up" and "top-down" neural systems. However, the temporal dynamics associated with the two systems in the development of delay discounting processes are not well known. In this study, we chose two age groups of participants and adopted event-related potential (ERP) techniques to investigate the neural dynamic differences between children and adults during delay discounting processes. Behavioral findings showed that children discounted more than adults and chose more immediate choices. Electrophysiological findings revealed that children exhibited longer neural processing (longer P2 latency) than adults during the early detection and identification phase. Children showed less cognitive control (smaller N2 amplitude) than adults over the middle frontal areas, and they devoted more neural effort (larger P3 amplitudes) to making final choices than adults. The factors of reward amount and time delay could influence the development of delay discounting in children.

Evaluating effects of episodic future thinking on valuation of delayed reward in cocaine use disorder: a pilot study

Background: Episodic future thinking (EFT; i.e., envisioning oneself in future contexts) has been demonstrated to reduce discounting of future reward in healthy adults. While this approach has the potential to support future-oriented decision-making in substance use recovery, the impact of EFT on discounting behavior in illicit stimulant users has not yet been evaluated.Objectives: This pilot study aimed to (1) assess the feasibility of utilizing EFT methods in individuals with cocaine use disorder (CUD) and (2) conduct preliminary measurement of the EFT effect on discounting behavior in this population.Methods: Eighteen treatment-seeking individuals with CUD (17 males) were interviewed about positive and neutral events expected to occur at a range of future latencies. Future event information identified by participants was subsequently included on a subset of trials in an intertemporal choice task to promote EFT; within-subject differences in discounting between standard and EFT conditions were evaluated.Results: Participants identified relevant events and demonstrated decreased discounting of future reward when event descriptors were included (relative to discounting without event descriptors; p = .039). It was further noted that most events identified by participants were goals, rather than plans or significant dates.Conclusion: While methods previously used to study the effect of EFT on discounting behavior in healthy individuals are also effective in individuals with CUD, methodological factors - including types of events identified - should be carefully considered in future work. These preliminary findings suggest that EFT can reduce impulsive decision-making in cocaine use disorder and may therefore have therapeutic value.

The neural basis underlying the relation between the action identification level and delay discounting: The medial and orbital frontal cortex functional connectivity with the precuneus

Previous studies have elucidated that action identification level brings ubiquitous effects in human life. The higher identification level is widely associated with future-oriented perspective, goal-directed actions, less impulsivity and so forth. However, little is known about how it relates to delay discounting. To address this issue, we sought to investigate the neural underpinning to understand their relations using voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) approaches. The behavioral results revealed that higher identification level was correlated with less discounting rate. The VBM results showed that gray matter (GM) volumes in left orbitofrontal cortex (OFC), left medial prefrontal cortex (mPFC) and right superior frontal gyrus (SFG) were positively correlated with action identification level. The RSFC results found that action identification level was positively associated with the functional connectivity between left OFC-left precuneus, and left mPFC-right precuneus respectively. Moreover, the structural equation modeling (SEM) showed that the association between the identification level and delay discounting was completely mediated by coupling of combined left OFC-left precuneus and left mPFC-right precuneus. These findings suggested that the functional communications within these brain regions in valuation and episodic prospection may account for the relationship between action identification level and delay discounting. The results enhanced our understanding of their relations from neural basis.

The associations of comorbid substance use disorders and psychiatric conditions with adolescent brain structure and function: A review

Adolescence is a period of rapid neural and behavioral development that often precipitates substance use, substance use disorders (SUDs), and other psychopathology. While externalizing disorders have been closely linked to SUD epidemiologically, the comorbidity of internalizing disorders and SUD is less well understood. Neuroimaging studies can be used to measure structural and functional developments in the brain that mediate the relationship between psychopathology and SUD in adolescence. Externalizing disorders and SUD are both associated with structural and functional changes in the basal ganglia and prefrontal cortex in adolescence. The neural mechanisms underlying internalizing disorders and SUD are less clear, but evidence points to involvement of the amygdala and prefrontal cortex. We also highlight independent contributions of SUD, which may vary in certain ways by the substances assessed. A deeper understanding of the neural basis of the relationship between psychopathology and SUD will allow for more informed interventions in this critical developmental stage.

Time preference and personal value: a population-based cross-sectional study in Japan

Objective

This study aimed to investigate the association between time preference (i.e., time discounting and hyperbolic time discounting) and personal values (the areas of priority values and commitment to value) in a sample of adult community residents in Japan.

Methods

Data from respondents (N = 2787) who completed the wave 1 and 3 surveys of a three-wave panel study of adult community residents in municipalities in Tokyo and suburban areas spanning 2010–2017 were analysed. Time discount rate and hyperbolic discount were measured using a three-item choice-based scale at the wave 1. Areas of priority value at present and at age 15 were measured by 11 questions for different value areas at the wave 3; the commitment to value at present and age 15 was measured by the Personal Value Questionnaire-II (PVQ-II) at the wave 3. Linear regression analyses were conducted of priority areas of values and commitment to value on time preference indicators, adjusting for sociodemographic variables and childhood socioeconomic status.

Results

After excluding those with missing responses, data from 1880 and 1958 respondents were subject to analyses on time discounting and hyperbolic time discounting, respectively. Time discount rate was significantly and negatively associated with the value area of maintaining a stable life at present. Hyperbolic time discounting was significantly and negatively associated with the commitment to value at age 15.

Conclusion

There may be an association between time preference and personal values. Time discounting and hyperbolic time discounting may be associated with different aspects of personal values, i.e., area of priority values and commitment to value, respectively.

Striatal bases of temporal discounting in early adolescents

Steeper rates of temporal discounting-the degree to which smaller-sooner (SS) rewards are preferred over larger-later (LL) ones-have been associated with impulsive and ill-advised behaviors in adolescence. Yet, the underlying neural systems remain poorly understood. Here we used a well-established temporal discounting paradigm and functional MRI (fMRI) to examine engagement of the striatum-including the caudate, putamen, and ventral striatum (VS)-in early adolescence (13-15 years; N = 27). Analyses provided evidence of enhanced activity in the caudate and VS during impulsive choice. Exploratory analyses revealed that trait impulsivity was associated with heightened putamen activity during impulsive choices. A more nuanced pattern was evident in the cortex, with the dorsolateral prefrontal cortex mirroring the putamen and posterior parietal cortex showing the reverse association. Taken together, these observations provide an important first glimpse at the distributed neural systems underlying economic choice and trait-like individual differences in impulsivity in the early years of adolescence, setting the stage for prospective-longitudinal and intervention research.

Food is discounted more steeply than money: Evidence from N2 and P3 responses in delay discounting tasks

In decision making, different rewards such as money and food may lead to different behavioral outcomes and neural dynamics. In this study, we used event-related potential (ERP) techniques and delay discounting tasks with money and snacks as rewards to determine whether there are differences in behavior and neurophysiology across the two tasks. The results showed that participants not only behaved differently but also showed different neural patterns in the money and snack tasks. In particular, at the behavioral level, participants discounted snacks more than money. At the neural level, the N2 amplitudes in the snack task were more negative than those in the money task. It was also discovered that for females, the amplitudes of P3 in the snack task were larger than those in money, while there was no difference for males. The current study showed the essential roles of frontal cognitive control function during varied delay discounting processes on money and food rewards.

Neural correlates of delay discount alterations in addiction and psychiatric disorders: A systematic review of magnetic resonance imaging studies

Delay discounting (DD) represents decreased subjective value for delayed reward relative to the same reward at present. The concept of DD has been applied for pathophysiology of addiction and psychiatric disorders. However, the detailed neuroimaging correlates of DD underlying pathophysiology still remain unclear. Thus, we conducted a systematic review to investigate neural correlates of DD on magnetic resonance imaging studies among addiction and psychiatric disorders. Specific search terms were set on PubMed to identify relevant articles. Initial search identified 551 records and 31 studies met the inclusion criteria. 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. As the neural basis related to DD, three neural networks have been proposed that are associated with the actions of short-term interests and long-term benefits. Among the three potential neural networks on DD, the first one included the ventromedial prefrontal cortex and ventral striatum and implicated in evaluating reward values, the second network included the anterior cingulate cortex and linked to cognitive control, and the third network included the middle temporal gyrus and was involved in predictions and affection. 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.

Changes in delay discounting, substance use, and weight status across adolescence

OBJECTIVE

Higher rates of delay discounting have been consistently linked to maladaptive health behaviors, including substance use and overeating, among adults. Despite adolescence representing a critical period for the escalation of these risky health behaviors, little is known about the developmental course of delay discounting or how this construct relates to important health outcomes in youth. The current study examined change in delay discounting over time using a latent growth curve approach and the relation between growth in this construct and changes in substance use and body-mass index over a 6-year period.

METHOD

Participants included 247 adolescents (44% female) with a mean age of 13 at the initial assessment.

RESULTS

Findings suggest that, on average, rates of delay discounting are stable across adolescence; however, there are significant individual differences around this trajectory. Moreover, youth who demonstrate significant increases in delay discounting over time are also more likely to experience more rapid escalations of both substance use and Body Mass Index across adolescence.

CONCLUSIONS

Results indicate that delay discounting is an important trans-disease process among adolescents. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The neural substrates responsible for how trait anxiety affects delay discounting: Right hippocampal and cerebellar connectivity with bistable right inferior parietal lobule

Delay discounting, an indicator of impulsivity, refers to the extent of devaluing future rewards. Studies have found that individuals with trait anxiety generally depreciate the later larger rewards, showing steeper delay discounting rates. However, little is known about the neural substrates responsible for how trait anxiety affects individuals' delay discounting. To address this question, we employed the voxel-based morphometry (VBM) and resting-state functional connectivity (RSFC) methods to explore the neural substrates of trait anxiety responsible for delay discounting. Behavioral results showed that trait anxiety was significantly positively correlated with delay discounting rates. The VBM analysis revealed that gray matter volumes of the right hippocampus (RHPC) and right cerebellum (RCere) were significantly positively correlated with trait anxiety. Moreover, the RSFC results showed that bistable right inferior parietal lobule (RIPL) connectivity with the RHPC and RCere were all inversely associated with trait anxiety. More importantly, mediation analysis indicated that trait anxiety played a completely mediating role in the relation between functional connectivity of RHPC-RIPL and RCere-RIPL and delay discounting. These results suggested that bistable RIPL connectivity with RHPC and RCere could be neural substrates underlying the effect of trait anxiety on delay discounting. On the whole, the current study yields insights into how trait anxiety affects delay discounting and provides a novel account from a neural basis perspective.

The preference for future outcomes correlates with the temporal variability of functional connectivity among brain regions

People inevitably make decisions between short-term and long-term consequences across domains like education, health and economics. In this kind of decision, the tendency to discount the value of later-larger rewards with increasing delays is defined as delay discounting (DD). A recent review has suggested that three neural systems which respectively responsible for valuation, prospection and cognitive control (e.g., ventromedial prefrontal cortex [vmPFC], hippocampus, precuneus and dorsolateral prefrontal cortex [dlPFC]) could interact with each other flexibly to have impacts on DD. However, to date, there is little attention paid on the connection between the DD and the dynamic interaction of brain regions.To tackle this issue, we investigate the relationship between the DD and the time-varying connectivity among brain regions in two samples of young adults. Results in sample 1 found that the DD was negatively correlated with the temporal variability of functional connectivity [FC] between the vmPFC and precuneus, and between the vmPFC and the left superior frontal gyrus. And the temporal variabilities of FC between the ventral striatum and right dlPFC, and between the ventral striatum and dorsomedial prefrontal cortex were also negatively related to DD. Furthermore, the main results were well replicated and validated in another sample using different analysis parameters. Overall, our findings reveal that temporal fluctuation of FC within default mode and fronto-striatal circuits can favor for prospecting future, cognitive control and valuation of delayed incentives, and this flexible connectivity patterns generally have association with preference for future outcomes.

Intertemporal decision-making-related brain states predict adolescent drug abuse intervention responses

Adolescent drug misuse represents a major risk factor for long-term drug use disorders. However, wide individual differences in responses to first-line behavioral therapies targeting adolescent drug misuse limit critical early intervention. Identifying the neural signatures of those adolescents most likely to respond to an intervention would potentially guide personalized strategies for reducing drug misuse. Prior to a 14-week evidence-based intervention involving combinations of contingency management, motivational enhancement, and cognitive behavioral therapy, thirty adolescent alcohol and/or cannabis users underwent fMRI while performing a reward delay discounting (DD) task tapping an addiction-related cognition. Intervention responses were longitudinally characterized by both urinalysis and self-report measures of the percentage of days used during treatment and in post-treatment follow-up. Group independent component analysis (ICA) of task fMRI data identified neural processing networks related to DD task performance. Separate measures of wholesale recruitment during immediate reward choices and within-network functional connectivity among selective networks significantly predicted intervention-related changes in drug misuse frequency. Specifically, heightened pre-intervention engagement of a temporal lobe "reward motivation" network for impulsive choices on the DD task predicted poorer intervention outcomes, while modes of functional connectivity within the reward motivation network, a prospection network, and a posterior insula network demonstrated robust associations with intervention outcomes. Finally, the pre-intervention functional organization of the prospection network also predicted post-intervention drug use behaviors for up to 6 months of follow-up. Multiple functional variations in the neural processing networks supporting preference for immediate and future rewards signal individual differences in readiness to benefit from an effective behavioral therapy for reducing adolescent drug misuse. The implications for efforts to boost therapy responses are discussed.

Adolescent Brain Response to Reward Is Associated with a Bias toward Immediate Reward

The current study examines associations between neural activation to the receipt of monetary reward in a rewarding game task and bias toward immediate reward measured in a behavioral delay discounting task among early adolescents (N = 58, 12-14 years). As expected, heightened brain activation in reward-related regions were correlated with higher bias toward immediate reward. This suggests that bias toward immediate reward in delay discounting tasks may be linked to heightened activation to reward in reward processing regions. This interplay between neural reward processing and bias toward immediate reward might explain the sharp increases in bias toward immediate reward that occur in early adolescence.

Pattern classification differentiates decision of intertemporal choices using multi-voxel pattern analysis

In daily life, individuals frequently make trade-offs between the small-but-immediate benefits and large-but-delayed profits. This type of decision is known as intertemporal choice. Previous studies have uncovered the neurobiological mechanism of the intertemporal choice, but it still remains unclear how the patterns of brain activity predict the decisions of intertemporal choices. To fill this gap, we used functional magnetic resonance imaging (fMRI), in conjunction with the machine learning technique of multi-voxel pattern analysis (MVPA), to ascertain the predictive capability of the neuronal pattern for classifying individuals' intertemporal decisions across two independent samples. To further probe how this neuronal pattern worked in predicting individual intertemporal decision, we drew on the Power Atlas to examine the accuracies of classification within each regional mask as well. Classification findings showed that the pattern of neuronal activity over the whole-brain can correctly classify the accuracies of individual decisions up to 84.3%. Encouragingly, further analysis shows that the neuronal information encoded in three brain functional networks can predict individuals' decisions with significant discriminative power in cross-samples, namely the valuation network (e.g., striatum), the cognitive control network (e.g., dorsolateral prefrontal cortex) and the episodic prospection network (e.g., amygdala, parahippocampus gyrus, insula). Collectively, these findings advance our comprehension of the neuronal mechanism of human intertemporal decisions, and substantially reshape our understanding for this cardinal behaviour from behavioural-brain scheme to brain-behavioural configuration.

Neural activation during delay discounting is associated with 6-month change in risky sexual behavior in adolescents

Background

Identifying cognitive and neural mechanisms of decision making in adolescence can enhance understanding of, and interventions to reduce, risky health behaviors in adolescence. Delay discounting, or the propensity to discount the magnitude of temporally distal rewards, has been associated with diverse health risk behaviors, including risky sex. This cognitive process involves recruitment of reward and cognitive control brain regions, which develop on different trajectories in adolescence and are also implicated in real-world risky decision making. However, no extant research has examined how neural activation during delay discounting is associated with adolescents' risky sexual behavior.

Purpose

To determine whether a relationship exists between adolescents' risky sexual behavior and neural activation during delay discounting.

Methods

Adolescent participants completed a delay discounting paradigm during functional magnetic resonance imaging (fMRI) scanning, and they reported risky sexual behavior at baseline, 3-, 6-, 9-, and 12-month follow-up time points. Latent growth curve models were employed to determine relationships between brain activation during delay discounting and change in risky sexual behavior over time.

Results

Greater activation in brain regions associated with reward and cognitive control (caudate, putamen, nucleus accumbens, anterior cingulate, insula, orbitofrontal cortex, inferior frontal gyrus, dorsolateral prefrontal cortex) during delay discounting was associated with lower mean levels of risky sexual behavior but greater growth over the period from baseline to 6 months.

Conclusions

Neural activation during delay discounting is cross-sectionally and prospectively associated with risky sexual behavior in adolescence, highlighting a neural basis of risky decision-making as well as opportunities for early identification and intervention.

Diminished Cortical Thickness Is Associated with Impulsive Choice in Adolescence

Adolescence is characterized by both maturation of brain structure and increased risk of negative outcomes from behaviors associated with impulsive decision-making. One important index of impulsive choice is delay discounting (DD), which measures the tendency to prefer smaller rewards available soon over larger rewards delivered after a delay. However, it remains largely unknown how individual differences in structural brain development may be associated with impulsive choice during adolescence. Leveraging a unique large sample of 427 human youths (208 males and 219 females) imaged as part of the Philadelphia Neurodevelopmental Cohort, we examined associations between delay discounting and cortical thickness within structural covariance networks. These structural networks were derived using non-negative matrix factorization, an advanced multivariate technique for dimensionality reduction, and analyzed using generalized additive models with penalized splines to capture both linear and nonlinear developmental effects. We found that impulsive choice, as measured by greater discounting, was most strongly associated with diminished cortical thickness in structural brain networks that encompassed the ventromedial prefrontal cortex, orbitofrontal cortex, temporal pole, and temporoparietal junction. Furthermore, structural brain networks predicted DD above and beyond cognitive performance. Together, these results suggest that reduced cortical thickness in regions known to be involved in value-based decision-making is a marker of impulsive choice during the critical period of adolescence.SIGNIFICANCE STATEMENT Risky behaviors during adolescence, such as initiation of substance use or reckless driving, are a major source of morbidity and mortality. In this study, we present evidence from a large sample of youths that diminished cortical thickness in specific structural brain networks is associated with impulsive choice. Notably, the strongest association between impulsive choice and brain structure was seen in regions implicated in value-based decision-making; namely, the ventromedial prefrontal and orbitofrontal cortices. Moving forward, such neuroanatomical markers of impulsivity may aid in the development of personalized interventions targeted to reduce risk of negative outcomes resulting from impulsivity during adolescence.

Coupling and segregation of large-scale brain networks predict individual differences in delay discounting

Decision-making about rewards, which requires us to choose between different time points, generally refers to intertemporal choice. Converging evidence suggests that some of the brain networks recruited in the delay discounting task have been well characterized for intertemporal choice. However, little is known about how the connectivity patterns of these large-scale brain networks are associated with delay discounting. Here, we use a resting-state functional connectivity MRI (rs-fcMRI) and a graph theoretical analysis to address this question. We found that the delay discounting rates showed a positive correlation with the functional network connectivity (FNC) between the cingulo-opercular network (CON) and the default mode network (DMN), while they showed a negative correlation with the FNC of both the CON-SAN (salience network) and the SAN-FPN (fronto-parietal network). Our results showed the association of both coupling and segregating processes with large-scale brain networks in delay discounting. Thus, the present study highlights the pivotal role of the functional connectivity patterns of intrinsic large-scale brain networks in delay discounting and extends our perspective on the neural mechanism of delay discounting.

Neural congruence between intertemporal and interpersonal self-control: Evidence from delay and social discounting

Behavioral studies using delay and social discounting as indices of self-control and altruism, respectively, have revealed functional similarities between farsighted and social decisions. However, neural evidence for this functional link is lacking. Twenty-five young adults completed a delay and social discounting task during fMRI scanning. A spatiotemporal partial least squares analysis revealed that both forms of discounting were well characterized by a pattern of brain activity in areas comprising frontoparietal control, default, and mesolimbic reward networks. Both forms of discounting appear to draw on common neurocognitive mechanisms, regardless of whether choices involve intertemporal or interpersonal outcomes. We also observed neural profiles differentiating between high and low discounters. High discounters were well characterized by increased medial temporal lobe and limbic activity. In contrast, low discount rates were associated with activity in the medial prefrontal cortex and right temporoparietal junction. This pattern may reflect biological mechanisms underlying behavioral heterogeneity in discount rates.

Delay discounting is associated with the fractional amplitude of low-frequency fluctuations and resting-state functional connectivity in late adolescence

As a component of self-regulation, delay discounting (DD) refers to an individual’s tendency to prefer smaller-but-sooner rewards over larger-but-later rewards and plays an essential role in many aspects of human behavior. Although numerous studies have examined the neural underpinnings of DD in adults, there are far fewer studies focusing on the neurobiological correlates underlying DD in adolescents. Here, we investigated the associations between individual differences in DD and the fractional amplitude of low-frequency fluctuations (fALFF) and resting-state functional connectivity (RSFC) in 228 high school students using resting-state functional magnetic resonance imaging (RS-fMRI). At the regional level, we found an association between higher DD and greater fALFF in the dorsal anterior cingulate cortex (dACC), which is involved in conflict monitoring and strategy adaptation. At the connectivity level, DD was positively correlated with the RSFC between the dACC and the left dorsolateral prefrontal cortex (DLPFC), a critical functional circuit in the cognitive control network. Furthermore, these effects persisted even after adjusting for the influences of general intelligence and trait impulsivity. Overall, this study reveals the fALFF and RSFC as the functional brain basis of DD in late adolescents, aiding to strengthen and corroborate our understanding of the neural underpinnings of DD.

An adaptive, individualized fMRI delay discounting procedure to increase flexibility and optimize scanner time

Research on the rate at which people discount the value of future rewards has become increasingly prevalent as discount rate has been shown to be associated with many unhealthy patterns of behavior such as drug abuse, gambling, and overeating. fMRI research points to a fronto-parietal-limbic pathway that is active during decisions between smaller amounts of money now and larger amounts available after a delay. Researchers in this area have used different variants of delay discounting tasks and reported various contrasts between choice trials of different types from these tasks. For instance, researchers have compared 1) choices of delayed monetary amounts to choices of the immediate monetary amounts, 2) 'hard' choices made near one's point of indifference to 'easy' choices that require little thought, and 3) trials where an immediate choice is available versus trials where one is unavailable, regardless of actual eventual choice. These differences in procedure and analysis make comparison of results across studies difficult. In the present experiment, we designed a delay discounting task with the intended capability of being able to construct contrasts of all three comparisons listed above while optimizing scanning time to reduce costs and avoid participant fatigue. This was accomplished with an algorithm that customized the choice trials presented to each participant with the goal of equalizing choice trials of each type. We compared this task, which we refer to here as the individualized discounting task (IDT), to two other delay discounting tasks previously reported in the literature (McClure et al., 2004; Amlung et al., 2014) in 18 participants. Results show that the IDT can examine each of the three contrasts mentioned above, while yielding a similar degree of activation as the reference tasks. This suggests that this new task could be used in delay discounting fMRI studies to allow researchers to more easily compare their results to a majority of previous research while minimizing scanning duration.

Executive functioning and substance use in adolescence: Neurobiological and behavioral perspectives

The current review is guided by the theoretical perspective that emphasizes the regulating role of executive functioning (Carver et al., 2009) and presents studies that elucidate the ways that executive functioning (inhibition and working memory) explain individual differences in adolescent substance use independently or by regulating the reactive system (reward and punishment sensitivity). Behavioral studies indicate that main effects of executive functioning on adolescent substance use are often nonsignificant or weak in effect sizes. In contrast, emerging evidence suggests consistent and stronger regulating effects of executive functioning over reward and punishment sensitivity. Functional neuroimaging studies reveal significant associations between executive functioning task-related hemodynamic responses and substance use with strong effect sizes. There is also direct evidence from studies testing statistical interactions of the regulating effects of EF-related brain activation, and indirect evidence in studies examining functional connectivity, temporal discounting, and reinforced control. We note key future directions and ways to address limitations in existing work.

Delay discounting and parental monitoring in adolescents with poorly controlled type 1 diabetes

In a sample of adolescents with poorly controlled type 1 diabetes, this study examined if delay discounting, the extent to which individuals prefer immediate over delayed rewards, was associated with severity of non-adherence and poor glycemic control, and if parental monitoring of diabetes management moderated those associations. Sixty-one adolescents (M _age = 15.08 years, SD 1.43) with poorly controlled type 1 diabetes completed a delayed discounting task and an HbA1c blood test. Adherence was assessed via self-monitoring of blood glucose (SMBG) data from adolescents' glucometers. Parents completed a parental monitoring questionnaire. Greater delay discounting was associated with higher HbA1c, but not SMBG. Direct parent observation of diabetes tasks, but not indirect parental monitoring, moderated the link between greater delay discounting and higher HbA1c, with higher direct parent observation buffering the link between greater discounting and poorer glycemic control. Delay discounting may be a target for future interventions to improve HbA1c in youth with type 1 diabetes.

Neural mechanisms of individual differences in temporal discounting of monetary and primary rewards in adolescents

Adolescents are generally characterized as impulsive. However, impulsivity is a multi-dimensional construct that involves multiple component processes. Which of these components contribute to adolescent impulsivity is currently unclear. This study focused on the neural mechanisms underlying individual differences in distinct components of temporal discounting (TD), i.e., the preference for smaller immediate rewards over larger delayed rewards. Participants were 58 adolescents (12-16 years-old) who performed an fMRI TD task with both monetary and snack rewards. Using mixed-effects modeling, we determined participants' average impatience, and further decomposed TD choices into: 1) amount sensitivity (unique contribution of the magnitude of the immediate reward); and 2) delay sensitivity (unique contribution of delay duration). Adolescents' average impatience was positively correlated with frontoparietal and ventral striatal activity during delayed reward choices, and with ventromedial prefrontal cortex activity during immediate reward choices. Adolescents' amount sensitivity was positively associated with ventral striatal and dorsal anterior cingulate cortex activity during immediate reward choices. Delay sensitivity was positively correlated with inferior parietal cortex activity during delayed reward choices. As expected, snacks were discounted more steeply than money, and TD of both reward types was associated with overlapping activation in the inferior parietal cortex. Exploring whether testosterone or estradiol were associated with TD and its neural correlates revealed no significant associations. These findings indicate that distinct components contribute uniquely to TD choice and that individual differences in amount sensitivity are uniquely associated with activation of reward valuation areas, while individual differences in delay sensitivity are uniquely associated with activation of cognitive control areas.

Sensitive periods of substance abuse: Early risk for the transition to dependence

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Early substance use dramatically increases the risk of substance use disorder (SUD).

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Although many try drugs, only a small percentage transition to SUD.

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High reactivity of reward, habit, and stress systems increase risk.

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Identification of early risk enables targeted, preventative interventions for SUD.

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Prevention must start before the sensitive adolescent period to maximize resilience.

Early adolescent substance use dramatically increases the risk of lifelong substance use disorder (SUD). An adolescent sensitive period evolved to allow the development of risk-taking traits that aid in survival; today these may manifest as a vulnerability to drugs of abuse. Early substance use interferes with ongoing neurodevelopment to induce neurobiological changes that further augment SUD risk. Although many individuals use drugs recreationally, only a small percentage transition to SUD. Current theories on the etiology of addiction can lend insights into the risk factors that increase vulnerability from early recreational use to addiction. Building on the work of others, we suggest individual risk for SUD emerges from an immature PFC combined with hyper-reactivity of reward salience, habit, and stress systems. Early identification of risk factors is critical to reducing the occurrence of SUD. We suggest preventative interventions for SUD that can be either tailored to individual risk profiles and/or implemented broadly, prior to the sensitive adolescent period, to maximize resilience to developing substance dependence. Recommendations for future research include a focus on the juvenile and adolescent periods as well as on sex differences to better understand early risk and identify the most efficacious preventions for SUD.

Neural Systems Underlying Individual Differences in Intertemporal Decision-making

Excessively choosing immediate over larger future rewards, or delay discounting (DD), associates with multiple clinical conditions. Individual differences in DD likely depend on variations in the activation of and functional interactions between networks, representing possible endophenotypes for associated disorders, including alcohol use disorders (AUDs). Numerous fMRI studies have probed the neural bases of DD, but investigations of large-scale networks remain scant. We addressed this gap by testing whether activation within large-scale networks during Now/Later decision-making predicts individual differences in DD. To do so, we scanned 95 social drinkers (18-40 years old; 50 women) using fMRI during hypothetical choices between small monetary amounts available "today" or larger amounts available later. We identified neural networks engaged during Now/Later choice using independent component analysis and tested the relationship between component activation and degree of DD. The activity of two components during Now/Later choice correlated with individual DD rates: A temporal lobe network positively correlated with DD, whereas a frontoparietal-striatal network negatively correlated with DD. Activation differences between these networks predicted individual differences in DD, and their negative correlation during Now/Later choice suggests functional competition. A generalized psychophysiological interactions analysis confirmed a decrease in their functional connectivity during decision-making. The functional connectivity of these two networks negatively correlates with alcohol-related harm, potentially implicating these networks in AUDs. These findings provide novel insight into the neural underpinnings of individual differences in impulsive decision-making with potential implications for addiction and related disorders in which impulsivity is a defining feature.

Contingency Management Approaches for Adolescent Substance Use Disorders

Multiple interventions for treating adolescents with substance use disorders have demonstrated efficacy, but a majority of teens do not show an enduring positive response to these treatments. Contingency management (CM)-based strategies provide a promising alternative, and clinical research focused on the development and testing of innovative CM models continues to grow. This article provides an updated review on the progress made in this area. It is important to continue to search for more effective models, focus on post-treatment maintenance (reduce relapse), and strive for high levels of integrity and fidelity during dissemination efforts to optimize outcomes.

Determinants of choice, and vulnerability and recovery in addiction

Addiction may be viewed as choice governed by competing contingencies. One factor impacting choice, particularly as it relates to addiction, is sensitivity to delayed rewards. Discounting of delayed rewards influences addiction vulnerability because of competition between relatively immediate gains of drug use, e.g. intoxication, versus relatively remote gains of abstinence, e.g. family stability. Factors modifying delay sensitivity can be modeled in the laboratory. For instance, increased delay sensitivity can be similarly observed in adolescent humans and non-human animals. Similarly, genetic factors influence delay sensitivity in humans and animals. Recovery from addiction may also be viewed as choice behavior. Thus, reinforcing alternative behavior facilitates recovery because reinforcing alternative behavior decreases the frequency of using drugs. How reinforcing alternative behavior influences recovery can also be modeled in the laboratory. For instance, relapse risk decreases as abstinence duration increases, and this decreasing risk can be modeled in animals using choice procedures. In summary, addiction in many respects can be conceptualized as a problem of choice. Animal models of choice disorders stand to increase our understanding of the core processes that establish and maintain addiction and serve as a proving ground for development of novel treatments.

Managing Chronic Pain in Special Populations with Emphasis on Pediatric, Geriatric, and Drug Abuser Populations

In the adult population chronic pain can lead to loss of productivity and earning potential, and decreased quality of life. There are distinct groups with increased vulnerability for the emergence of chronic pain. These groups may be defined by developmental status and/or life circumstances. Within the pediatric, geriatric, and drug abuser populations, chronic pain represents a significant health issue. This article focuses on known anatomic, physiologic, and genetic mechanisms underlying chronic pain in these populations, and highlights the need for a multimodal approach from multiple health care professionals for management of chronic pain in those with the most risk.

The impact of therapists' words on the adolescent brain: In the context of addiction treatment

At this time, we still do not know how therapist behaviors influence adolescent brain response and related treatment outcomes. Therefore, we examined this question with 17 binge drinking youth (mean age=16.62 years; 64.3% female; 42.9% Hispanic; 28.6% bi-/multi-racial). In this within-subjects design, all youth completed a baseline assessment, two therapy sessions, an fMRI scan, and were re-evaluated for behavior change at one-month post-treatment. During the fMRI session, youth were presented with two types of responses from their treating therapist: higher-skill statements prescribed in an empirically-supported addiction treatment (complex reflections) vs. language standard within addiction treatment more broadly (closed questions). In terms of behavior change, at the one-month follow-up, youth showed significant reductions in number of drinking days and binge drinking days. Further, we found main effects for complex reflections and closed questions across the superior middle temporal gyrus and middle temporal gyrus (FWE-corrected, p<.05). Greater brain response was observed for complex reflections versus closed questions within the bilateral anterior cingulate gyrus. Greater BOLD response in the parietal lobe during closed questions was significantly associated with less post-treatment drinking. Lower BOLD response during complex reflections and closed questions in the precuneus were associated with greater post-treatment ratings of importance of changing. This study represents a first step in understanding how therapist behaviors influence the developing adolescent brain and how that neural response may be associated with youth treatment outcomes.

A comparison of delay discounting in adolescents and adults in treatment for cannabis use disorders

Delay discounting is associated with problematic substance use and poorer treatment outcomes in adolescents and adults with substance use disorders. Although some research has addressed delay discounting among individuals with cannabis use disorders (CUDs), results have been equivocal, and no study has examined whether discounting rates differ between adolescent and adult cannabis users. The aim of this study was to compare discounting rates between adolescents and adults in treatment for CUD to determine whether discounting at intake or changes in discounting across treatment differed between age groups. Participants were 165 adolescents and 104 adults enrolled in treatment for CUD. Participants completed a delay discounting task at intake and end of treatment for 2 commodities (money and cannabis) at 2 different magnitudes ($100 and $1,000). Repeated measures mixed models examined differences in discounting rates by commodity and magnitude across age groups at intake and changes in discounting across treatment. At intake, adolescents discounted money more than adults whereas adults showed greater discounting at $100 magnitude than $1,000. In addition, adults had greater decreases in discounting of cannabis over the course of treatment. Overall, adolescents appeared less sensitive to changes in magnitude of rewards, discounted money at higher rates, and showed less improvement in discounting over the course of treatment compared to adults. Comparing delay discounting in adolescents and adults with CUD can contribute to a better understanding of how development influences the effect of discounting on substance use to better inform treatment for substance use disorders.

A dual-systems perspective on addiction: contributions from neuroimaging and cognitive training

Dual-systems theories explain lapses in self-control in terms of a conflict between automatic and deliberative modes of behavioral control. Numerous studies have now tested whether the brain areas that control behavior are organized in a manner consistent with dual-systems models. Brain regions directly associated with the mesolimbic dopamine system, the nucleus accumbens and ventromedial prefrontal cortex in particular, capture some of the features assumed by automatic processing. Regions in the lateral prefrontal cortex are more closely linked to deliberative processing and the exertion of self-control in the suppression of impulses. While identifying these regions crudely supports dual-systems theories, important modifications to what constitutes automatic and deliberative behavioral control are also suggested. Experiments have identified various means by which automatic processes may be sculpted. Additional work decomposes deliberative processes into component functions such as generalized working memory, reappraisal of emotional stimuli, and prospection. The importance of deconstructing dual-systems models into specific cognitive processes is clear for understanding and treating addiction. We discuss intervention possibilities suggested by recent research, and focus in particular on cognitive training approaches to bolster deliberative control processes that may aid quit attempts.

Present simple and continuous: emergence of self-regulation and contextual sophistication in adolescent decision-making

Sophisticated, intentional decision-making is a hallmark of mature, self-aware behaviour. Although neural, psychological, interpersonal, and socioeconomic elements that contribute to such adaptive, foresighted behaviour mature and/or change throughout the life-span, here we concentrate on relevant maturational processes that take place during adolescence, a period of disproportionate developmental opportunity and risk. A brief, eclectic overview is presented of recent evidence, new challenges, and current thinking on the fundamental mechanisms that mature throughout adolescence to support adaptive, self-controlled decision-making. This is followed by a proposal for the putative contribution of frontostriatal mechanisms to the moment-to-moment assembly of evaluative heuristics that mediate increased decision-making sophistication, promoting the maturation of self-regulated behaviour through adolescence and young adulthood.