Comorbid depression, antisocial personality, and substance dependence: Relationship with delay discounting

Delay discounting is associated with addiction and mental health measures while controlling for health behaviors and health barriers in a large US sample

Background

Excessive discounting of future rewards [delay discounting (DD)] may be a transdiagnostic process and treatment target underlying behavioral health outcomes, including trauma, depression, anxiety, and problematic substance use. However, multiple health behaviors and barriers are also related to these outcomes, including social media usage, adverse childhood experiences (ACEs), sleep quality, healthcare access, housing status, and exercise. To extend research examining DD as transdiagnostic process, we recruited a large, heterogenous sample to examine the association between DD, problematic substance use, and mental health outcomes while controlling for certain health behaviors and health barriers.

Method

In a cross-sectional online survey of 3992 US residents, we administered validated measures of PTSD, depression, anxiety, and problematic alcohol, stimulant, and opioid use. Using linear or ordinal logistic models, scores for each outcome were regressed onto DD while controlling for demographics, health behaviors, and health barriers.

Results

Including only DD and demographics, DD was associated with each outcome at low effect sizes (ƒ2 = .013, OR range = 1.08-1.16). Except for opioid ASSIST scores, these relationships held when controlling for social media usage, sleep, housing status, healthcare access, ACEs, physical exercise, and demographic variables (ƒ2 = .002, OR range = 1.03-1.12), increasing confidence that DD concurrently and directly relates to four of these five clinical outcomes.

Discussion

These findings support the conceptualization of DD as a transdiagnostic process underlying certain psychopathologies and suggest targeting DD in co-occurring substance use disorder and/or mental health treatments may result in clinically significant outcomes.

Changes in substance use, recovery, and quality of life during the initial phase of the COVID-19 pandemic

BACKGROUND

The COVID-19 pandemic disrupted lives on a massive scale. While the pandemic appeared to worsen mental health outcomes broadly, its effects on alcohol/substance use and recovery are unclear. Many studies convolved the sociopolitical unrest beginning in May 2020 with the pandemic. We assessed pandemic-related changes in substance use, recovery involvement, and quality of life among US adults at two specified time periods that isolated pandemic effects from potentially confounding sociopolitical factors.

OBJECTIVES

We tested the following hypotheses: the pandemic and consequent policies (1) increased use of alcohol and illicit substances in active users; (2) increased use of alcohol/substances among people in early recovery; (3) reduced participation in recovery activities among those in early recovery, and that (4) use amount and use events correlated with impulsivity in both groups and that (5) substance use and abstinence correlated with resilience.

METHODS

We recruited 1,685 participants through Amazon's Mechanical Turk (MTurk). We assessed demographics, quality of life, alcohol/substance use, recovery activities, and measures of impulsivity and resilience at two time points, pre-pandemic and (early) during-pandemic. Only n = 45 (Active Users; males n = 32) and n = 34 (Recovery; males n = 20) passed data quality checks and were included in the primary analyses.

RESULTS

Among Active Users, weekly alcohol consumption and days spent using alcohol and illicit substances decreased during the pandemic. Resilience negatively correlated with pandemic-related substance use in early recovering participants. Significant reduction in the quality of life was coincident with a trend of lower recovery activity participation (31% decline) during the pandemic.

CONCLUSIONS

The reduced alcohol/substance use and participation in recovery activities might be expected from conditions that promote social isolation. The high prevalence of low-quality data from MTurk cautions for careful use of online data sourcing.

Genome-wide association study of antisocial personality disorder diagnostic criteria provides evidence for shared risk factors across disorders

INTRODUCTION

While progress has been made in determining the genetic basis of antisocial behaviour, little progress has been made for antisocial personality disorder (ASPD), a condition that often co-occurs with other psychiatric conditions including substance use disorders, attention deficit hyperactivity disorder (ADHD), and anxiety disorders. This study aims to improve the understanding of the genetic risk for ASPD and its relationship with other disorders and traits.

METHODS

We conducted a genome-wide association study (GWAS) of the number of ASPD diagnostic criteria data from 3217 alcohol-dependent participants recruited in the UK (UCL, N = 644) and the USA (Yale-Penn, N = 2573).

RESULTS

We identified rs9806493, a chromosome 15 variant, that showed a genome-wide significant association ( Z -score = -5.501, P = 3.77 × 10 -8 ) with ASPD criteria. rs9806493 is an eQTL for SLCO3A1 (Solute Carrier Organic Anion Transporter Family Member 3A1), a ubiquitously expressed gene with strong expression in brain regions that include the anterior cingulate and frontal cortices. Polygenic risk score analysis identified positive correlations between ASPD and smoking, ADHD, depression traits, and posttraumatic stress disorder. Negative correlations were observed between ASPD PRS and alcohol intake frequency, reproductive traits, and level of educational attainment.

CONCLUSION

This study provides evidence for an association between ASPD risk and SLCO3A1 and provides insight into the genetic architecture and pleiotropic associations of ASPD.

A review of functional brain differences predicting relapse in substance use disorder: Actionable targets for new methods of noninvasive brain stimulation

Neuroimaging studies have identified a variety of brain regions whose activity predicts substance use (i.e., relapse) in patients with substance use disorder (SUD), suggesting that malfunctioning brain networks may exacerbate relapse. However, this knowledge has not yet led to a marked improvement in treatment outcomes. Noninvasive brain stimulation (NIBS) has shown some potential for treating SUDs, and a new generation of NIBS technologies offers the possibility of selectively altering activity in both superficial and deep brain structures implicated in SUDs. The goal of the current review was to identify deeper brain structures involved in relapse to SUD and give an account of innovative methods of NIBS that might be used to target them. Included studies measured fMRI in currently abstinent SUD patients and tracked treatment outcomes, and fMRI results were organized with the framework of the Addictions Neuroclinical Assessment (ANA). Four brain structures were consistently implicated: the anterior and posterior cingulate cortices, ventral striatum and insula. These four deeper brain structures may be appropriate future targets for the treatment of SUD using these innovative NIBS technologies.

Recovery from opioid use disorder: A 4-year post-clinical trial outcomes study

BACKGROUND

Opioid use disorder (OUD) seriously impacts public health in the United States. However, few investigations of long-term outcomes following treatment with medication for OUD exist. Additionally, these studies have prioritized opioid use and treatment utilization outcomes, and a gap in knowledge regarding long-term, multidimensional trajectories of OUD recovery exists. This study investigated a diverse array of outcomes for individuals with OUD at an average of 4.2 years post clinical trial participation.

METHODS

Individuals who previously participated in long-acting buprenorphine subcutaneous injection clinical trials (NCT023579011; NCT025100142; NCT02896296) and enrolled in The Remission from Chronic Opioid Use-Studying Environmental and SocioEconomic Factors on Recovery (RECOVER; NCT03604861) Study participated in a follow up assessment (n = 216). Substance use, psychosocial, opioid dependence, and delay discounting outcomes were assessed. Regression analyses were conducted to determine significant associations between psychosocial/opioid dependence variables and both recent opioid use and delay discounting.

RESULTS

The majority of participants reported abstinence from opioids since the last RECOVER study assessment (mean 2.26 years; 55%) and in the past 30 days (69%). Participants reported low levels of depression and psychological distress. Positive associations between depression and opioid craving with past 30-day opioid misuse and delay discounting, and negative associations between quality of life and treatment effectiveness with these outcomes were observed.

CONCLUSIONS

This study examined longer term OUD recovery outcomes. Participants reported high levels of abstinence from opioids and psychosocial functioning. These encouraging results highlight the multidimensional nature of recovery from OUD, and further support the effectiveness of buprenorphine as an OUD treatment.

Delay Discounting as a Potential Therapeutic Target for Weight Loss in Breast Cancer Survivors

Obesity in breast cancer (BC) survivors is associated with increased mortality. Delay discounting (DD) is a behavioral economic measure of how individuals value future outcomes. Higher DD correlates with obesity in the general population. Valuation of the future may be associated with obesity differently in cancer survivors. This study evaluated the relationship between DD and obesity in BC survivors. We report an exploratory analysis assessing cross-sectional associations between DD, BMI, and lifestyle behaviors (vegetable and fruit consumption, exercise) related to obesity in 89 women with hormone receptor positive non-metastatic BC. Multivariate linear regression analysis examined demographic and lifestyle behavior variables associated with both BMI and DD. Greater willingness to wait for larger, delayed rewards (lower DD) was significantly associated with lower BMI (standardized beta = −0.32; p < 0.01), independent of age, race, income, time since diagnosis, and menopausal status. There was no significant association between DD and fruit consumption or exercise frequency. Vegetable consumption was significantly associated with lower DD (standardized beta = 0.24; p < 0.05). Higher DD is associated with obesity and decreased frequency of vegetable consumption in BC survivors. Future studies should investigate DD as a therapeutic target for behavioral interventions to facilitate weight loss and promote longevity in this population.

A systematic review and meta-analysis of delay discounting and cannabis use

Delay discounting reflects the systematic reduction in the value of a consequence by delay to delivery. Theoretical and empirical work suggests that delay discounting is a key behavioral mechanism underlying substance use disorder. Existing work on cannabis use, however, is mixed with many studies reporting null results. The purpose of this review was to provide an in-depth assessment of the association between delay discounting and cannabis use. We conducted metaregression analyses to determine the omnibus correlation between delay discounting and cannabis use, and to evaluate task-based and sample-based moderators. Studies included evaluated an association between delay discounting and cannabis quantity-frequency or severity measures in human participants (27 studies, 61 effect sizes, 24,782 participants). A robust variance estimation method was used to account for dependence among effect sizes. A significant, but small, omnibus effect was observed (r = .082) in which greater cannabis use frequency or severity was associated with greater discounting. Incentive structure and outcome type were each significant moderators in a multiple moderator model such that incentivized tasks correlated with severity measures showed stronger associations (r = .234) than hypothetical tasks correlated with quantity-frequency measures (r = .029). Comparisons to historic effect size data supported the hypothesis that, at present, the relationship between cannabis use and delay discounting appears empirically smaller than for other substances. Future work should explore theoretical rationales explaining this modest relationship involving cannabis use and delay discounting, such as reflecting the smaller magnitude of perceived long-term clinical outcomes associated with cannabis compared to other substances. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Discounting, Cognitive Inflexibility, and Antisocial Traits as Predictors of Adolescent Drug Involvement

Cognitive impairments, such as steep delay discounting, have been correlated with substance-related disorders. However, antisocial traits, cognitive inflexibility, and loss discounting have been barely considered despite having a high relationship with problematic consumption. This study aims to identify the predictive power of these variables in four types of drug use. Fifty-two adolescents (age range of 13 to 19 years) were assessed with a substance involvement test, four discounting tasks using $3,000, a card sorting test, and antisocial screening. Discriminant analysis with simultaneous estimation and varimax rotation was carried out. Function one included discounting of both losses, function two AT and CI, and function three probabilistic gains. The three functions explained 60.1% of the variance. The results show that preference for small and soon punishments and larger and unlikely punishments distinguished non-use and experimental use of moderate consumption and problematic consumption. High antisocial traits and low cognitive inflexibility distinguished experimental use groups of non-use. Risk-taking did not discriminate effectively between moderate consumption and problematic consumption. A replication of this study with a larger sample size is recommended to verify the results.

Transdiagnostic neuroimaging of reward system phenotypes in ADHD and comorbid disorders

ADHD is a disorder characterized by changes in the reward system and which is highly comorbid with other mental disorders, suggesting common neurobiological pathways. Transdiagnostic neuroimaging findings could help to understand whether a dysregulated reward pathway might be the actual link between ADHD and its comorbidities. We here synthesize ADHD neuroimaging findings on the reward system with findings in obesity, depression, and substance use disorder including their comorbid appearance regarding neuroanatomical features (structural MRI) and activation patterns (resting-state and functional MRI). We focus on findings from monetary-incentive-delay (MID) and delay-discounting (DD) tasks and then review data on striatal connectivity and volumetry. Next, for better understanding of comorbidity in adult ADHD, we discuss these neuroimaging features in ADHD, obesity, depression and substance use disorder and ask whether ADHD heterogeneity and comorbidity are reflected by a common dysregulation in the reward system. Finally, we highlight conceptual issues related to heterogeneous paradigms, different phenotyping, longitudinal prediction and highlight some promising future directions for using striatal reward functioning as a clinical biomarker.

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.

Impairments in Executive Functioning in Patients with Comorbid Substance Use and Personality Disorders: A Systematic Review

The purpose of this systematic review was to examine the evidence for impaired executive functioning in patients diagnosed with a dual pathology of personality disorder (PD) and substance use disorder, and to identify whether differences exist in comparison to those with a single diagnosis. Methods: A systematic search was conducted to identify studies using measures of executive functioning in patients with PD-substance use disorder dual pathology. Sixteen studies were selected. Results: The results indicate that dual pathology patients with Cluster C personality disorder do not differ from controls, and that the presence of dual pathology does not influence the updating domain of executive functioning. The findings were inconclusive with regard to dual pathology patients with Cluster B personality disorders. Whilst the various studies consistently show that these patients show worse performance than the control groups, here are contradictory results with regard to whether Cluster B personality disorders add more alterations in executive functioning to those that already appear in substance use disorder. Conclusions: The results suggest the need for further research that more adequately controls variables such as time in treatment, medication, and sample size, whilst there is also a need to employ longitudinal designs that include more patients from Clusters A and C.

Associations Between Delay Discounting and Connectivity of the Valuation-control System in Healthy Young Adults

The process of valuation assists in determining if an object or course of action is rewarding. Delay discounting is the observed decay of a rewards' subjective value over time. Encoding the subjective value of rewards across a spectrum has been attributed to brain regions belonging to the valuation and executive control systems. The valuation system (VS) encodes reward value over short and long delays, influencing reinforcement learning and reward representation. The executive control system (ECS) becomes more active as choice difficulty increases, integrating contextual and mnemonic information with salience signals in the modulation of decision-making. Here, we aimed to identify resting-state functional connectivity-based patterns of the VS and ECS correlated with value-setting and delay discounting (outside-scanner paradigm) in a large (n = 992) cohort of healthy young adults from the Human Connectome Project (HCP). Results suggest the VS may be involved in value-setting of small, immediate rewards while the ECS may be involved in value-setting and delay discounting for large and small rewards over a range of delays. We observed magnitude sensitive connections involving the posterior cingulate cortex, time-sensitive connections with the ventromedial and lateral prefrontal cortex while connections involving the posterior parietal cortex appeared both magnitude- and time-sensitive. The ventromedial prefrontal cortex and posterior parietal cortex could act as "comparator" regions, weighing the value of small rewards against large rewards across various delay duration to aid in decision-making.

Behavioral economics and coping-related drinking motives in trauma exposed drinkers: Implications for the self-medication hypothesis

Behavioral economic theory can help researchers understand complex behavior by considering the availability and economic value associated with an individual's choices. This study explored how behavioral economic constructs relate to alcohol consumption and alcohol problems in a sample of trauma-exposed young adults. We further explored whether these behavioral economic constructs explained unique variance in alcohol outcomes beyond coping-related drinking motives. Participants were 91 trauma-exposed young adults who reported recent alcohol consumption (M_age = 26.53, female = 36.26%, non-White = 41.75%). Participants were recruited through Amazon Mechanical Turk. Questionnaires measured alcohol consumption, problems, and motives for use, as well as alcohol demand, delay discounting, future orientation, and access to environmental reward. Future orientation (ΔR2 = .05, p = .03) and delay discounting (ΔR2 = .04, p = .05) explained unique variance in alcohol problems after controlling for coping-related drinking motives. Further, alcohol demand indices (ΔR2s = .04-.10, ps = .00-.05) explained unique variance in alcohol consumption after controlling for coping-related drinking. Both coping motives and behavioral economic variables contribute to alcohol consumption and alcohol-related consequences among trauma-exposed young adults. Findings suggest that, beyond coping motives, behavioral economics may play a meaningful role in understanding alcohol misuse. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Delay Discounting as a Transdiagnostic Process in Psychiatric Disorders: A Meta-analysis

IMPORTANCE

Delay discounting is a behavioral economic index of impulsive preferences for smaller-immediate or larger-delayed rewards that is argued to be a transdiagnostic process across health conditions. Studies suggest some psychiatric disorders are associated with differences in discounting compared with controls, but null findings have also been reported.

OBJECTIVE

To conduct a meta-analysis of the published literature on delay discounting in people with psychiatric disorders.

DATA SOURCES

PubMed, MEDLINE, PsycInfo, Embase, and Web of Science databases were searched through December 10, 2018. The psychiatric keywords used were based on DSM-IV or DSM-5 diagnostic categories. Collected data were analyzed from December 10, 2018, through June 1, 2019.

STUDY SELECTION

Following a preregistered Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol, 2 independent raters reviewed titles, abstracts, and full-text articles. English-language articles comparing monetary delay discounting between participants with psychiatric disorders and controls were included.

DATA EXTRACTION AND SYNTHESIS

Hedges g effect sizes were computed and random-effects models were used for all analyses. Heterogeneity statistics, one-study-removed analyses, and publication bias indices were also examined.

MAIN OUTCOMES AND MEASURES

Categorical comparisons of delay discounting between a psychiatric group and a control group.

RESULTS

The sample included 57 effect sizes from 43 studies across 8 diagnostic categories. Significantly steeper discounting for individuals with a psychiatric disorder compared with controls was observed for major depressive disorder (Hedges g = 0.37; P = .002; k = 7), schizophrenia (Hedges g = 0.46; P = .004; k = 12), borderline personality disorder (Hedges g = 0.60; P < .001; k = 8), bipolar disorder (Hedges g = 0.68; P < .001; k = 4), bulimia nervosa (Hedges g = 0.41; P = .001; k = 4), and binge-eating disorder (Hedges g = 0.34; P = .001; k = 7). In contrast, anorexia nervosa exhibited statistically significantly shallower discounting (Hedges g = -0.30; P < .001; k = 10). Modest evidence of publication bias was indicated by a statistically significant Egger test for schizophrenia and at the aggregate level across studies.

CONCLUSIONS AND RELEVANCE

Results of this study appear to provide empirical support for delay discounting as a transdiagnostic process across most of the psychiatric disorders examined; the literature search also revealed limited studies in some disorders, notably posttraumatic stress disorder, which is a priority area for research.

Factor structure of the depression anxiety stress Scale-21 (DASS-21): Unidimensionality of the Arabic version among Egyptian drug users

BACKGROUND

Emotional distress is common among illicit drug users, and it can negatively affect treatment outcomes and increase the risk of relapse. Nonetheless, instruments that properly measure emotional distress are lacking. Therefore, this study investigated the factor structure of the Arabic Depression Anxiety Stress Scale-21 (DASS-21) in that population.

METHODS

The DASS-21 and the Self-stigma of Alcohol Dependence Scale (SSAD) were completed by 149 inpatient Egyptian drug users. The DASS-21 was examined using exploratory factor analysis, partial confirmatory factor analysis, and parallel analysis. For validation testing, correlations between stigma scores and DASS scores were computed.

RESULTS

A one-factor solution provided the best fit to the DASS-21 data. Four items with low loadings were removed. The resulting DASS-17 was also unidimensional, and its reliability was high (0.88). On the validation tests, the DASS scores correlated with the stigma scores as hypothesized.

CONCLUSION

Subscales of the Arabic version of the DASS-21 do not differentiate between depression and anxiety. A modified 17-item version (the DASS-17) was suitable for measuring overall distress, and the results of convergent validation testing indicated that it was superior to the DASS-21.

The relationship between delay discounting and alcohol dependence in individuals with and without comorbid psychopathology

RATIONALE

Alcohol use disorder (AUD) has been associated with greater discounting of delayed monetary rewards, but it is unclear whether this association is primarily related to alcohol consumption or is secondary to the presence of psychiatric comorbidities. It is also unclear if steeper rates of discounting are associated with greater AUD severity.

OBJECTIVE

We sought to determine whether the presence of comorbid psychiatric disorders affected the relationship between AUD and delay discounting. We also examined whether more severe AUD was associated with greater delay discounting.

METHODS

In this cross-sectional study, 793 adults completed a delay discounting task. Subjects were divided into four groups based on diagnosis: current AUD with psychiatric comorbidities (N = 226), current AUD without psychiatric comorbidities (N = 203), past AUD (N = 69), and healthy controls (N = 295). In those with AUD, we investigated the relationship between delay discounting and alcohol dependence symptom count and recent drinking history. We also compared individuals seeking treatment to non-treatment seeking individuals. Psychiatric comorbidities examined included mood disorders, anxiety disorders, and substance use disorders.

RESULTS

After adjusting for age, sex, income, and education, individuals with current AUD showed significantly higher rates of delay discounting than healthy controls and individuals with a past diagnosis of AUD. The presence of comorbid psychiatric diagnoses was not associated with steeper discounting. Among those with AUD, there was no evidence for a continuous relationship between delay discounting and AUD severity or alcohol consumption. Finally, non-treatment seekers with AUD had steeper delay discounting than treatment seekers.

CONCLUSIONS

Individuals with AUD show steeper delay discounting than healthy adults, but the effect is small and there is no added effect from comorbid psychopathology or increased AUD severity. This suggests that steeper delay discounting may have a more limited effect on human alcohol use than previously supposed.

Multidimensional Patterns of Sexual Risk Behavior and Psychiatric Disorders in Men with Substance Use Disorders

Previous evidence links substance use disorders (SUD) to STI/HIV risk and suggests that comorbid psychiatric disorders increase the probability to engage in sexual risk behaviors. This study had two aims: (1) to identify subgroups based on sexual risk behavior using a person-centered approach in a sample of substance users and (2) to measure the association of psychiatric and SUD with subgroup membership. We assessed 402 male adults with SUD, reporting sexual intercourse in the previous 12 months using the HIV-Risk Behavior Scale and the Mini International Neuropsychiatric Interview. Latent class analysis was performed to determine multidimensional patterns of sexual risk behaviors and multinomial logistic regression was utilized to associate classes with disorders. The three-class model showed the best fit, and the classes were labeled: Relationship-Based (31.34% of the sample), Condom-Based (39.55%), and Multiple Risks (29.10%). Controlling for age and marital status, major depressive disorders, antisocial personality disorder, and any psychiatric disorder were associated with the Multiple Risks class. Results stress the importance of developing a personalized assessment and counseling for sexual risk behaviors in individuals with SUD, particularly when they endorse criteria for comorbid psychiatric disorders. Future studies should focus on evaluating differential response to preventive interventions.

The impact of depressed mood, working memory capacity, and priming on delay discounting

BACKGROUND AND OBJECTIVES

The impaired ability to delay rewards, delay discounting (DD), is associated with several problematic conditions in which impulsive decision-making derails long-term goals. Working memory (WM), the ability to actively store and manipulate information, is associated with DD. The purpose of this study was to examine the effect of cognitive priming on DD and to identify moderation of this effect dependent on degree of WM capacity (WMC) and depressed mood.

METHODS

A WM task (n-back) was used as a cognitive prime before assessment of DD (Monetary Choice Questionnaire) and was compared to a similar prime from an inhibition task in a factorial design in 183 community participants. All participants completed a DD task and assessment of depressive symptoms (Beck Depression Inventory-II). Priming effects were evaluated relative to WMC of participants.

RESULTS

Higher WMC and lower depression scores were associated with greater relative preference for larger, delayed rewards. The effects of a WM prime were moderated by WMC; benefits of the prime were only evident for individuals with lower WMC. No effects were found for an alternative inhibition task.

LIMITATIONS

Limitations included depression scores mainly in subclinical range, use of hypothetical instead of real rewards in the DD task, and no examination of the time course of effects.

CONCLUSIONS

This study provides support for the effectiveness of a brief WM prime in enhancing ability to delay rewards. Priming may be a useful adjunctive intervention for individuals with WM dysfunction or conditions in which impulsive decision-making may derail long-term goals.

Free will in addictive behaviors: A matter of definition

Certain people are at risk for using alcohol or other drugs excessively and for developing problems with their use. Their susceptibility might arise from a variety of factors, including their genetic make-up, brain chemistry, family background, personality and other psychological variables, and environmental and sociocultural variables. Moreover, after substance use has become established, there are additional cognitive-motivational variables (e.g., substance-related attentional bias) that contribute to enacting behaviors consistent with the person's motivation to acquire and use the substance. People who are at such risk are likely to choose to use addictive substances even though doing so entails negative consequences. In the sense of complete freedom from being determined by causal factors, we believe that there is no such thing as free will, but defined as ability to make choices from among multiple options, even though the choices are ultimately governed by natural processes, addicted individuals are free to choose. Although they might appear unable to exercise this kind of free will in decisions about their substance use, addictive behaviors are ultimately always goal-directed and voluntary. Such goal pursuits manifest considerable flexibility. Even some severely addicted individuals can cease their use when the value of continuing the use abruptly declines or when the subjective cost of continuing the use is too great with respect to the incentives in other areas of their lives. Formal treatment strategies (e.g., contingency management, Systematic Motivational Counseling, cognitive training) can also be used to facilitate this reversal.

Impulsivity in personality disorders: current views and future directions

PURPOSE OF REVIEW

Impulsivity is considered a trans-diagnostic feature of many mental disorders, yet our understanding of the concept and approaches to measurement have evolved significantly with advances in neuroimaging. This review will provide an overview of impulsivity as it is currently understood, its association with personality disorder and implications for treatment.

RECENT FINDINGS

Impulsivity is now considered to involve failure of inhibitory control, either motor or cognitive, and deficits of the reward valuation system. Inhibitory control, and discounting of rewards are both independently associated with personality disorder. The tendency to choose immediate rewards over those with an associated delay is a feature of borderline personality disorder (BPD) regardless of conditions of stress. Deficits in response inhibition were also associated with BPD and were worsened under conditions of stress. These findings indicate that state impulsivity has an important role in the expression of impulsive behaviour. Exploratory studies measuring changes in these networks following psychotherapy have confirmed such methods could be used to measuring treatment response.

SUMMARY

Understanding the discrete mechanisms of impulsive decision-making and behavior, and their implications in personality disorder, offers new targets for diagnosis and intervention. Future research should aim to understand changes of impulsivity with development. Identifying the role of psychological and pharmacological intervention in modulating the development of impulsivity may prevent progression to personality disorder, and associated adverse outcomes.

Differences in decision-making as a function of drug of choice

Poor decision-making is a central feature of all substance use disorders (SUD), but substances vary in the legal and health consequences associated with their use. For example, while the negative health consequences associated with cigarette smoking are often years away, the consequences of heroin abuse can be fatal in mere hours. It remains unclear if users of these substances show decision-making patterns that differ with the relative riskiness of their drug of choice. To address this question, we reviewed studies that compared decision-making of individuals using different substances. We focused on studies assessing two of the most commonly investigated decision-making processes-delay discounting and risk taking-and specifically focused on decision-making that involved selection between options for hypothetical monetary rewards. For delay discounting, we reviewed studies that assessed decisions regarding delayed or immediate monetary rewards, and for risk-taking we reviewed studies using the Iowa Gambling Task. Studies directly comparing different SUD groups were limited in number and tended to compare alcohol or cocaine users to other substance users. Overall, these studies do not support the hypothesis that decision-making differed by drug of choice. Major limitations in the literature include failing to account for comorbid substance use and a lack of prospective longitudinal studies. Due to these limitations, conclusions should be considered provisional. Nonetheless, current findings suggest that these two facets of decision-making are similar across drugs of abuse.

Delay Discounting of Losses in Alcohol Use Disorders and Antisocial Psychopathology: Effects of a Working Memory Load

BACKGROUND

Alcohol use disorders (AUDs) are associated with increased discounting of delayed rewards and reduced executive working memory (eWM) capacity. This association is amplified when comorbid with antisocial psychopathology (AP). Furthermore, recent studies suggest that reduced WM capacity is associated with disinhibited decisions reflected by increased impulsive decision making on the delay discounting of rewards task. While discounting of delayed rewards is well studied, the discounting of delayed losses has received significantly less experimental attention.

METHODS

The current study investigated (i) the rate of discounting of delayed losses in individuals with AUD only (n = 61), AUD with comorbid AP (n = 79) and healthy controls (n = 64); (ii) the relationship between eWM capacity and discounting of delayed losses; and (iii) the effect of a WM load on discounting of delayed losses. Discounting performance was assessed using a computerized discounting of delayed losses task.

RESULTS

Results showed that the AUD-only and AUD-AP groups had higher rates of discounting of delayed losses and lower eWM capacity compared to the control groups. Lower individual eWM capacity was associated with increased discounting of delayed losses. However, WM load did not increase discounting rates overall.

CONCLUSIONS

These results support the hypothesis that greater discounting of delayed losses is associated with AUD and comorbid AP problems and lower individual eWM capacity.

Age and impulsive behavior in drug addiction: A review of past research and future directions

Impulsive behavior is implicated in the initiation, maintenance, and relapse of drug-seeking behaviors involved in drug addiction. Research shows that changes in impulsive behavior across the lifespan contribute to drug use and addiction. The goal of this review is to examine existing research on the relationship between impulsive behavior and drug use across the lifespan and to recommend directions for future research. Three domains of impulsive behavior are explored in this review: impulsive behavior-related personality traits, delay discounting, and prepotent response inhibition. First, we present previous research on these three domains of impulsive behavior and drug use across developmental stages. Then, we discuss how changes in impulsive behavior across the lifespan are implicated in the progression of drug use and addiction. Finally, we discuss the relatively limited attention given to middle-to-older adults in the current literature, consider the validity of the measures used to assess impulsive behavior in middle-to-older adulthood, and suggest recommendations for future research.

The Efficacy of Dog Assisted Therapy in Detained Drug Users: A Pilot Study in an Italian Attenuated Custody Institute

Drug addiction is a major care and safety challenge in prison context. Nowadays, rehabilitation and specific therapeutic programs are suggested to improve health and well-being of inmates during their detention time and to reduce substance abuse relapse after release from prison. Among these programs, several studies reported the benefits for inmates coming from animal assisted interventions. In this pilot controlled study, we investigated the efficacy of a dog assisted therapy program addressed to 22 drug addicted male inmates housed in an attenuated custody institute in Italy. The study lasted six months, the treated group (12 inmates) was involved once a week for one hour in 20 dog assisted therapy sessions, whereas the control group (10 inmates) followed the standard rehabilitation program. One week before the beginning and one week after the end of the sessions, all inmates involved were submitted to symptom checklist-90-revised and Kennedy axis V. Inmates involved in the dog assisted therapy sessions significantly improved their social skills, reducing craving, anxiety and depression symptoms compared to the control group. Despite the limitation due to the small number of inmates enrolled and to the absence of follow up, we found these results encouraging to the use of dog assisted therapy as co-therapy in drug addicted inmates rehabilitation programs, and we claim the need of more extensive study on this subject.

Cross-commodity delay discounting of alcohol and money in alcohol users

Despite real-world implications, the pattern of delay discounting in alcohol users when the commodities now and later differ has not been well characterized. In this study, 60 participants on Amazon's Mechanical Turk completed the Alcohol Use Disorder Identification Test (AUDIT) to assess severity of use and completed four delay discounting tasks between hypothetical, equivalent amounts of alcohol and money available at five delays. The tasks included two cross-commodity (alcohol now-money later and money now-alcohol later) and two same-commodity (money now-money later and alcohol now-alcohol later) conditions. Delay discounting was significantly associated with clinical cutoffs of the AUDIT for both of the cross-commodity conditions but not for either of the same-commodity delay discounting tasks. The cross-commodity discounting conditions were related to severity of use wherein heavy users discounted future alcohol less and future money more. The change in direction of the discounting effect was dependent on the commodity that was distally available suggesting a distinctive pattern of discounting across commodities when comparing light and heavy alcohol users.

Impulsivity and Cluster B Personality Disorders

PURPOSE OF REVIEW

Impulsivity is a multifaceted construct and an important personality trait in various mental health conditions. Among personality disorders (PDs), especially cluster B PDs are affected. The aims of this review are to summarize the relevant findings of the past 3 years concerning impulsivity in cluster B PDs and to identify those subcomponents of self-reported impulsivity and experimentally measured impulse control that are most affected in these disorders.

RECENT FINDINGS

All studies referred to antisocial (ASPD) or borderline PD (BPD), and none were found for narcissistic or histrionic PD. In ASPD as well as BPD, self-report scales primarily revealed heightened impulsivity compared to healthy controls. In experimental tasks, ASPD patients showed impairments in response inhibition, while fewer deficits were found in delay discounting. BPD patients showed specific impairments in delay discounting and proactive interference, while response inhibition was less affected. However, after inducing high levels of stress, deficits in response inhibition could also be observed in BPD patients. Furthermore, negative affect led to altered brain activation patterns in BPD patients during impulse control tasks, but no behavioral impairments were found. As proposed by the DSM-5 alternative model for personality disorders, heightened impulsivity is a core personality trait in BPD and ASPD, which is in line with current research findings. However, different components of experimentally measured impulse control are affected in BPD and ASPD, and impulsivity occurring in negative emotional states or increased distress seems to be specific for BPD. Future research could be focused on measures that assess impulsive behaviors on a momentary basis as this is a promising approach especially for further ecological validation and transfer into clinical practice.