Neuroscience-informed classification of prevention interventions in substance use disorders: An RDoC-based approach

Neuroscience has contributed to uncover the mechanisms underpinning substance use disorders (SUD). The next frontier is to leverage these mechanisms as active targets to create more effective interventions for SUD treatment and prevention. Recent large-scale cohort studies from early childhood are generating multiple levels of neuroscience-based information with the potential to inform the development and refinement of future preventive strategies. However, there are still no available well-recognized frameworks to guide the integration of these multi-level datasets into prevention interventions. The Research Domain Criteria (RDoC) provides a neuroscience-based multi-system framework that is well suited to facilitate translation of neurobiological mechanisms into behavioral domains amenable to preventative interventions. We propose a novel RDoC-based framework for prevention science and adapted the framework for the existing preventive interventions. From a systematic review of randomized controlled trials using a person-centered drug/alcohol preventive approach for adolescents, we identified 22 unique preventive interventions. By teasing apart these 22 interventions into the RDoC domains, we proposed distinct neurocognitive trajectories which have been recognized as precursors or risk factors for SUDs, to be targeted, engaged and modified for effective addiction prevention.

Interpersonal ethnic-racial discrimination and tobacco products: The moderating role of critical action

OBJECTIVE

The present study aimed to understand the role of critical action, sociopolitical participation, an essential form of consciousness in the relationship between interpersonal discrimination and the use of tobacco products.

METHOD

The present study was part of a more extensive longitudinal study on students' genetic and environmental experiences. To examine these associations, 164 racially minoritized college students (Mage = 19.86, SD = 0.28) were surveyed for this study.

RESULTS

Findings indicated that the relation between interpersonal ethnic-racial discrimination (IERD) and tobacco products was moderated by critical action. Specifically, IERD was associated with greater use of tobacco products when students had low critical consciousness-critical action. The relation between IERD and the use of tobacco products became nonsignificant when students had high critical action.

CONCLUSIONS

Critical action was protective in mitigating increased tobacco use in the context of discrimination experiences. Research, clinical, and policy implications are discussed in efforts to reduce tobacco-related disparities among racially minoritized college students. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The impact of the COVID-19 pandemic on alcohol use disorder symptoms: Testing interactions with polygenic risk

Objective: The purpose of this study was to test whether COVID impact interacts with genetic risk (polygenic risk score/PRS) to predict alcohol use disorder (AUD) symptoms. Method: Participants were n = 455 college students (79.6% female, 51% European Ancestry/EA, 24% African Ancestry/AFR, 25% Americas Ancestry/AMER) from a longitudinal study during the initial stage (March-May 2020) of the pandemic. Path models allowed for the examination of PRS and previously identified COVID-19 impact constructs. Results: There was a main effect of the AUD PRS on AUD symptoms within the EA group (β: .165, p < .01). Additionally, food/housing insecurity was predictive in the AMER group (β.295, p < .05), and greater increases in substance use were associated with AUD symptoms for EA (β:.459, p < .001) and AMER groups (β:.468, p < .001). Conclusions: Greater food/housing instability and increases in substance use, as well higher scores on PRS are associated with more AUD symptoms for some ancestral groups within this college sample.

COVID-19-Induced Inequalities and Mental Health: Testing the Moderating Roles of Self-rated Health and Race/Ethnicity

This study examines the relationship among COVID-19-induced social, economic, and educational inequalities on mental health (i.e., anxiety and depression). This study also examines if levels of self-rated health (SRH) moderate the relationship (i.e., COVID-induced inequalities [CII] and mental health), as well as examines the racial/ethnic group differences among 567 young adults in the mid-Atlantic region. Using a moderation model, results indicate that CII were significantly related to depression (b = .221, t(554) = 4.59, p = .000) and anxiety (b = .140, t(555) = 3.23, p = .001). SRH and race/ethnicity also moderated both relationships. At above-average SRH (i.e., moderator), higher CII were also significantly related to lower anxiety (Asian young adults only) and lower depression (Asian and White young adults only). Overall, SRH and race/ethnicity are important factors in the mental health impact of COVID-19 on young adults.

Interactions between COVID-19 family home disruptions and relationships predicting college students' mental health over time

The present study tested whether family home disruptions during the COVID-19 pandemic in the Spring 2020 (Time 1; T1) informed mental health (i.e., posttraumatic stress disorder [PTSD], depressive, and anxiety symptoms) 7 months later in Fall 2020 at T2 and whether family relationship quality moderated relations. Multigroup path analysis models were used to test whether there were significant differences in relations by emerging adults' ethnic-racial backgrounds. Participants were 811 Black, Asian American, Latine, and White emerging adult college students (Mage = 19.95, SD = .33), and the majority (79.6%) who reported their gender identified as cisgender women. Results indicated that across all individuals, T1 family relationship quality moderated relations between T1 family home disruptions and T2 anxiety and depressive symptoms. At lower levels of T1 family relationship quality, family home disruptions predicted greater T2 depressive and anxiety symptoms. At higher levels of T1 family relationship quality, these relations were not significant. Findings highlight that family relationship quality is an important protective factor for diverse emerging adult college students. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Comparing psychopathy across measurement modalities

Psychopathy is a collection of personality traits and behaviors that are associated with costly personal, interpersonal, and societal outcomes. The nature of this construct has been widely debated across decades of literature, and such debates have produced a multitude of instruments for the measurement of psychopathy. These measures include self-reports and clinical interviews, yet little work has examined the degree to which measurements of psychopathy may differ across these modalities and whether such potential differences may impact the associations commonly found with psychopathy (e.g., impulsivity). To this end, we applied psychometric network and item response theory analyses to data obtained from the interview-based Psychopathy Checklist: Screening Version and the Levenson Self-Report of Psychopathy in the same sample. Our results revealed similarities and differences across measurement modalities. Regarding the Psychopathy Checklist: Screening Version, Factor 2 items were more important to the psychopathy construct (i.e., the most central and contributed more information than Factor 1 items), whereas Factor 1 items were more important to the Levenson Self-Report of Psychopathy. Factor 1 items were positively linked with Positive Urgency and were either negatively associated or not associated with Negative Urgency. In contrast, Factor 2 items were positively linked with Negative Urgency in both networks. Our analyses also revealed that dishonesty and irresponsibility served as the primary bridges connecting the factors of psychopathy in both networks. We make suggestions for improving the assessment of psychopathy by implementing self-report and interview measures that allow scores to be compared directly. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Neurocognitive Impulsivity in Opiate Users at Different Lengths of Abstinence

The aim of the current study was to examine the effects of length of abstinence on decision making (impulsive choice) and response inhibition (impulsive action) in former opiate users (OU). Participants included 45 OU in early remission [0−12 months of abstinence], 68 OU in sustained remission [>12 months of abstinence], and 68 control participants. Decision making was assessed with the Iowa Gambling Task (IGT), the Cambridge Gambling Task (CGT), and the Monetary Choice Questionnaire (MCQ). Response inhibition was examined with the Stop Signal Task (SST), and the Go/No-Go Task (GNG). Results revealed group differences in decision making under risk (CGT) and ambiguity (IGT), where control participants displayed better decision making compared to OU in early remission. Both groups of former OU were also characterized by higher discounting of delayed rewards (MCQ). Regression analyses revealed minimal effects of length of abstinence on performance on decision-making tasks and no effects on delay discounting. In addition, both OU groups showed reduced action inhibition (GNG) relative to controls and there were no group differences in action cancellation (SST). Length of abstinence had no effect on response inhibition. Overall, our findings suggest that neurocognitive function may not fully recover even with protracted abstinence, which should be addressed by relapse prevention and cognitive remediation programs for OU.

Identifying distinct profiles of impulsivity for the four facets of psychopathy

Psychopathy comprises antagonistic personality traits and antisocial behaviors that are associated with critical outcomes for the individual and society (e.g., violent behavior). Since its inception, impulsivity has been theorized as a core feature of psychopathy. Research supports this assertion, yet psychopathy and impulsivity are both multifaceted constructs. As such, the associations commonly observed between psychopathy and impulsivity may obscure more nuanced profiles of impulsivity that are only observable at the facet-level. To address this gap in the literature, we collected data from a community sample using a clinical psychopathy interview along with dispositional and neurobehavioral measures of impulsivity. We regressed each of the four facets of psychopathy onto eight impulsivity variables. We followed these analyses with bootstrapped dominance analyses in order to determine which of the impulsivity variables shared the most variance with each psychopathy facet. Our analyses revealed that positive urgency was the most important aspect of impulsivity to all four facets of psychopathy. We further identified distinct profiles of impulsivity linked to each psychopathy facet-the interpersonal facet was typified by sensation seeking and temporal impulsivity. The affective and lifestyle facets were both typified by general trait impulsivity and affective impulsivity. The antisocial facet was typified by affective impulsivity and sensation seeking. Such distinct profiles of impulsivity suggest that specific behaviors linked with each facet (e.g., manipulativeness and the interpersonal facet) may be explained in part by the distinct forms of impulsivity aligned with them.

A Longitudinal Investigation of Resilience as a Protective Factor During the COVID-19 Pandemic

COVID-19 is a global stressor that has been shown to impact mental health outcomes. Given that COVID-19 is a unique stressor that has been shown to have mental health consequences, identifying protective factors is imperative. The protective influences of resilience are demonstrated through the extant literature, though less is known about resilience and COVID-19 impact. The current study seeks to expand the existing literature on resilience, and on mental health outcomes influenced by COVID-19, by longitudinally investigating relative resilience as a buffer against posttraumatic stress disorder (PTSD) symptoms and alcohol consumption, in the wake of a global pandemic. Participants included 549 undergraduates with a history of lifetime trauma exposure. Using a longitudinal path model, we tested the interaction between relative resilience (i.e., an individual's deviation from distress levels predicted by prior trauma exposure relative to other individuals in the same cohort) and COVID-19 impact domains (i.e., social media use, worry, exposure, change in substance use, and housing/food insecurity) on PTSD symptoms and alcohol consumption. Findings demonstrate a significant interaction between the COVID-19 worry impact domain and baseline resilience on later PTSD symptoms, whereby COVID-19 worry impacts PTSD symptoms at low levels of resilience (β = .26, p < .001), marginally impacts PTSD symptoms at mean levels of resilience (β = .09, p = .05), and does not impact PTSD symptoms at high levels of resilience (β = -.08, p = .16). There were no significant main effects nor interaction effects of resilience on alcohol consumption. This article adds to the literature on resilience and COVID-19 through examining both internalizing (i.e., PTSD) and substance use outcomes, using longitudinal data, and using a quantitative measure of resilience.

Genetically influenced externalizing and internalizing risk pathways as novel prevention targets

Objective: Risky substance use among college students is widespread, and associated with numerous adverse consequences. Current interventions focus primarily on students' current substance use; we hypothesize that shifting focus from current use to underlying risk factors is a complementary approach that may improve effectiveness of prevention/intervention programming. This approach aligns with the personalized medicine movement, which aims to harness knowledge about underlying etiological factors to provide individuals with specific information about their unique risk profiles and personalized recommendations, to motivate and enable individuals to better self-regulate their health. Method: Our group is building and evaluating an online Personalized Feedback Program (PFP) for college students that provides feedback about the individual's underlying genetically influenced externalizing and internalizing risk factors for substance use, along with personalized recommendations/resources. The project capitalizes on work from a university-wide research project (Spit for Science; S4S), in which > 12,000 students (˜70% of 5 years of incoming freshmen) are being followed longitudinally to assess substance use and related factors across the college years. In this article, we describe our foundational work to develop the PFP. Results: From the S4S data, we have identified risk factors across four domains (Sensation Seeking, Impulsivity, Extraversion, and Neuroticism) that are correlated with college students' substance use. We developed an online self-guided PFP, in collaboration with professionals from student affairs, and using feedback from students, with the ultimate goal of conducting a randomized clinical trial. Conclusion: The provision of personalized risk information represents a novel approach to complement and extend existing college substance use programming. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Impulsivity and reduced quality of life in persons with paraplegia

BACKGROUND: Low Quality of Life (QoL) in persons with paraplegia may stem from impulsive behaviors. Impulsivity in persons with paraplegia and persistently low QoL has seldom been probed but could be targeted with cognitive behavioral therapies. OBJECTIVE: Determine how task-assessed and self-report impulsivity relate to quality of life (QoL) in adults with paraplegia. METHODS: In a preliminary study, 33 adults with paraplegia after traumatic SCI were administered verbal interviews on QoL from the PROMIS item bank at baseline and at six-month follow-up, along with several computerized metrics of impulsivity at baseline. RESULTS: A cluster of (n = 10) participants characterized by high levels of negative affect and low levels of resilience and life satisfaction across both baseline and follow-up showed significantly greater negative urgency impulsivity (p = 0.007) as well as significantly lower mindfulness and self-care in some domains (all p = 0.05), compared to the cluster of participants (n = 23) who showed higher life satisfaction and resilience. Behavioral metrics of delay discounting and rapid-response (motoric) impulsivity did not significantly differ (all p >  0.05) between the two clusters of participants. CONCLUSIONS: These data suggest that novel interventions that reduce trait impulsivity in other disorders could be applied to potentially reduce risk for reduced self-care and QoL in individuals with paraplegia.

Attentional function and inhibitory control in different substance use disorders

Attentional function in substance use disorder (SUD) is not well understood. To probe attentional function in SUD as a function of primary substance of abuse, we administered the attentional network task (ANT) to 44 individuals with Cocaine Use Disorder (CoUD), 49 individuals with Cannabis Use Disorder (CaUD), 86 individuals with Opioid Use Disorder (OUD), and 107 controls with no SUD, along with the stop-signal task (SST). The ANT quantifies the effects of (temporal) alerting cues and (spatial) orienting cues to reduce reaction time (RT) to targets, as well as probing how conflicting (target-incongruent) stimuli slow RT. The SST quantifies individuals' ability to inhibit already-initiated motor responses. After controlling for sex representation and age, OUD and CaUD participants showed blunted alerting effects compared to controls, whereas CaUD and CoUD participants showed greater stimulus conflict (flanker) effects. Finally, CoUD participants showed a trend toward increased orienting ability. In SST performance, no SUD group showed a prolonged stop-signal reaction compared to controls. However, the OUD group (and CoUD group at trend level) showed prolonged "go" RT to targets and reduced hit rates. These data indicate differences in attentional function in persons with SUD as a function of the primary substance use.

2021 NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR PAEDIATRIC COMPUTED TOMOGRAPHY IN EGYPT

OBJECTIVE

To establish national diagnostic reference levels (NDRLs) for most common paediatric computed tomography (CT) examinations in Egypt.

METHODS

This was a prospective study that included all dedicated paediatric imaging centers in Egypt. Data from 1680 individual paediatric patients undergoing CT scanning of the head, chest and abdomen-pelvis were collected. Computed tomography dose indices were recorded, data were analysed and compared with the internationally published paediatric DRLs in14 countries.

RESULTS

The Egyptian NDRLs of the CTDIvol (mGy) for head, chest and abdomen-pelvis scans among four paediatric age groups were found to be (23, 27, 28, 32, 4, 5, 6, 8, 5, 6, 7, 9) mGy, respectively; and the corresponding NDRLs of the DLP (mGycm) for head, chest and abdomen-pelvis scans were found to be (345, 428, 499, 637, 67, 85, 145, 215, 97, 135, 240, 320) mGycm, respectively. There were variations in the radiation doses between CT centers and identical scanners indicating the need for dose optimization. The NDRLs of the CTDIvol (mGy) and the DLP (mGycm) values were similar to or lower than international DRLs.

CONCLUSION

This study summarizes the results of the first Egyptian Computed Tomography survey that provides national diagnostic reference levels for paediatric patients in Egypt. Despite the reasonable NDRLs values, the study depicted certain pros and cons concerning CT practice, and identified some problems that hinder the process of optimization as well as justification in children.

Fluid Intelligence Moderates the Link Between Psychopathy and Aggression Differently for Men and Women

Research on sex differences in the association of psychopathy with fluid intelligence is limited, and it remains unknown if fluid intelligence plays a meaningful role in explaining the psychopathy-aggression link for men and women. The present study aimed to test for sex differences in the relation between the four-facet model of psychopathy and intelligence, and to assess whether fluid intelligence moderates the link between psychopathy and aggression. In a community sample of men (n = 356) and women (n = 196), we assessed psychopathy using the Psychopathy Checklist: Screening Version (PCL:SV), fluid intelligence using the Raven's Progressive Matrices, and types of aggression using the Aggression Questionnaire (AQ). Hierarchical regressions showed that the psychopathy lifestyle facet was negatively associated with intelligence and there were no sex differences. Our analyses for types of aggression revealed sex differences and similarities. For both men and women, total AQ scores were predicted by higher antisocial facet scores. Lower intelligence moderated the link between higher antisocial facet scores and aggression in men, but not for women. Physical aggression in women was associated with higher interpersonal, affective, and antisocial facet scores, whereas for men, it was only associated with higher antisocial facet scores. Verbal and indirect aggression were associated with higher intelligence in both men and women. For men only, higher antisocial facet scores were associated with verbal and indirect aggression. Higher intelligence moderated the link between the lifestyle facet and indirect aggression for women, whereas for men, it moderated the link between the affective facet and indirect aggression. This study further highlights sex differences in mechanisms of psychopathy-related aggression, which need to be considered in the development of violence interventions and risk assessment.

Divergent changes: abstinence and higher-frequency substance use increase among racial/ethnic minority young adults during the COVID-19 global pandemic

BACKGROUND

Identifying factors influencing substance use among racial/ethnic minorities (REM) is important given the disproportionate impact of the COVID-19 pandemic on this population.

OBJECTIVES

We examined factors in four domains and hypothesized that poor mental health, negative coping behaviors, negative environmental aspects, and belonging to more vulnerable social groups would be associated with increased substance use during the pandemic.

METHODS

Multiple regression was applied to longitudinal data from a college sample assessed prior (fall 2017 to spring 2019) and during (spring 2020) the pandemic (n= 323; 81.5% cisgender women; 34.5% African-American, 36.1% Asian-American, 15.5% Hispanic/Latinx, 11.8% multi-racial) to identify factors predicting current alcohol, cannabis, and nicotine use frequency (spring 2020) and change in frequency of use between springs 2019 and 2020.

RESULTS

While infrequent substance use (monthly or less) decreased during the pandemic, abstinence rates increased (alcohol 39%; cannabis 18%; nicotine 18%) and higher-frequency alcohol use increased (207%-1600% 2-3 times+/week) compared to spring 2019. The strongest protective factor was change in living situation during the pandemic, associated with lower current alcohol and cannabis use. Risk factors included a history of trouble with police and impulsivity since the pandemic, both associated with higher current and increased alcohol and cannabis use. REM did not differ on most factors and the outcomes. However, a higher percentage of Asian-Americans than other REM reported living situation changes.

CONCLUSION

Substance use rates diverged during the pandemic, with both increased abstinence and higher-frequency use, attributed mostly to mental health and environmental domain factors with few REM differences.

The COVID-19 pandemic impacts psychiatric outcomes and alcohol use among college students

BACKGROUND

The COVID-19 pandemic has imposed fundamental challenges on nearly every area of life.

OBJECTIVE

The purpose of the current study was to expand on the literature on the impact of the pandemic on college students by a) examining domains of impact of the pandemic on psychiatric and alcohol outcomes and b) controlling for pre-pandemic outcomes.

METHOD

Participants included 897 college students (78.6% female) from a larger longitudinal study on college student mental health. Structural equation models were fit to examine how COVID-19 impact (exposure, worry, food/housing insecurity, change in social media use, change in substance use) were associated with PTSD, anxiety, depression, suicidal ideation, and alcohol phenotypes. Models were fit to adjust for pre-pandemic symptoms.

RESULTS

No effects of COVID-19 exposure remained after adjusting for earlier outcomes. COVID-19 worry predicted PTSD, depression, and anxiety, even after adjusting for earlier levels of outcomes (β's: .091-.180, p's < .05). Housing/food concerns predicted PTSD, anxiety, and depression symptoms as well as suicidal ideation (β's: .085-.551, p's < .05) after adjusting for earlier levels of symptoms. Change in media use predicted alcohol consumption (β's: ± .116-.197, p's < .05). Change in substance use affected all outcomes except suicidality (β's: .112-.591, p's < .05).

CONCLUSIONS

Domains of COVID-19 impact had differential effects on mental health and substance outcomes in college students during the first wave of the coronavirus pandemic. Future studies should examine the trajectory of these factors on college student mental health across waves of the pandemic.

Physical Abuse Explains Sex Differences in the Link Between Psychopathy and Aggression

Psychopathy has long been associated with aggression. However, few studies have looked at differences between men and women. Studies that do exist demonstrate that psychopathy differentially relates to aggression in men and women and indicate that environmental factors may play a significant role in influencing these associations. A key environmental factor is a history of lifetime physical abuse (LPA), which has been linked to aggressive behavior in both men and women. The aim of the present study was to test if psychopathy differentially predicted physical, verbal, and indirect aggression in men and women, and if these associations were moderated by LPA. In a large community sample of men (n = 369) and women (n = 204), we assessed the 4-facet model of psychopathy (Interpersonal, Affective, Lifestyle, Antisocial) with the Psychopathy Checklist: Screening Version, LPA with the Addiction Severity Index, and self-report aggression with the Aggression Questionnaire. Results revealed sex differences and similarities. Physical aggression was associated with the affective facet of psychopathy in both men and women, though in different directions based on the moderating effects of LPA. Verbal aggression was associated with higher antisocial facet scores and LPA for men and not women. Finally, indirect aggression was associated with the antisocial facet of psychopathy for men, and the interpersonal facet for women, and these associations were not moderated by LPA. In women, low antisocial facet scores and no LPA were found to be protective for indirect aggression. These results show that LPA and psychopathy generally increase the risk of aggression, but the interaction between LPA and psychopathy differentiates the risk of aggression forms for men and women. These sex differences highlight the need for female-responsive interventions to target sex-specific risk factors for aggressive behavior.

Large differences in education and training of radiographers in Europe and Central Asia: Results from an IAEA coordinated study

INTRODUCTION

Education and training of radiographers is known to be diverse between countries and regions. Under an IAEA project, this work collected data on radiographer education for the Europe and Central Asia region with a particular focus on radiation protection gaps and potential actions.

METHODS

Following piloting, an electronic questionnaire was distributed to all national counterparts for the IAEA Technial Coopearation (TC) Europe region (n = 33 countries) and nominated national representatives. Contacts were additionally invited to a virtual workshop to discuss and rank common problems in education and training of radiographers and to propose potential solutions.

RESULTS

Responses were received from 31 countries, including 14 from the European Union. Just over half of countries reported radiographer education being in higher education with 71% having program durations more than 3 years (range: 1 month-4 years). Programs included a spectrum of both clinical training and radiation protection hours with ten-fold variations noted across the region. Inclusion of core radiation protection topics within curricula varied similarly, as did radiographers' clinical involvement in both justification and optimisation between countries. Workshop participants identified five common training problems, namely education availability, lack of standardisation, radiation protection course quality, teamwork problems and lack of equipment.

CONCLUSION

Radiographer education in the IAEA Europe region is heterogeneous with substantial differences in duration and quality of training programs between countries, which likely impact on quality of patient care delivered. Common problems have been identified and potential solutions proposed to focus quality improvement initiatives.

IMPLICATIONS FOR PRACTICE

Radiographer education and training is diverse throughout the IAEA TC Europe region, with likely impacts on radiation protection practices applied. Clinical involvement of radiographers in justification and optimisation differs, potentially limiting adherence to radiation protection principles.

Unpacking the impact of the COVID-19 pandemic: identifying structural domains

Background: The novel coronavirus-19 (COVID-19) pandemic is a collective crisis that imposed an abrupt and unprecedented impact on college students, as universities were closed with little warning. Paired with the challenges associated with physical distancing (e.g. economic stress, job loss, food insecurity, housing challenges) and the simultaneous need to balance continued and new academic demands, impact will be wide-ranging. It is critical to determine the structure of the impact of this heterogeneous stressor (e.g. health concerns, pandemic worry, financial concerns) for prevention and intervention planning. Objective: Through an existing recruitment pipeline we were in a unique position to study the wide-ranging reach of this pandemic in a cohort of students for whom their university experiences were like no other cohort in history. Method: Data were collected from students who were in their third year of college during the onset of the pandemic; of the N = 1,899 in the cohort who were invited to participate in this COVID-related survey, 897 (47.2%) completed measures of impact between May and July of 2020. Results: A series of confirmatory and exploratory models were fit to examine the structure of the pandemic-related domains. Following estimation of a single-factor model, a correlated five factors model, as well as two second-order factor structures, the five correlated factors (exposure, worry, housing/food instability, social media, substance use) model was found to represent the data most appropriately, while producing an interpretable solution. Conclusions: These measurement model analyses set the stage for future research to examine how these correlated factors impact psychiatric, substance, and academic outcomes in this vulnerable population.

Development of a novel computational model for the Balloon Analogue Risk Task: The Exponential-Weight Mean-Variance Model

The Balloon Analogue Risk Task (BART) is a popular task used to measure risk-taking behavior. To identify cognitive processes associated with choice behavior on the BART, a few computational models have been proposed. However, the extant models either fail to capture choice patterns on the BART or show poor parameter recovery performance. Here, we propose a novel computational model, the exponential-weight mean-variance (EWMV) model, which addresses the limitations of existing models. By using multiple model comparison methods, including post hoc model fits criterion and parameter recovery, we showed that the EWMV model outperforms the existing models. In addition, we applied the EWMV model to BART data from healthy controls and substance-using populations (patients with past opiate and stimulant dependence). The results suggest that (1) the EWMV model addresses the limitations of existing models and (2) heroin-dependent individuals show reduced risk preference than other groups, which may have significant clinical implications.

Social Information Processing in Substance Use Disorders: Insights From an Emotional Go-Nogo Task

Positive social connections are crucial for recovery from Substance Use Disorder (SUD). Of interest is understanding potential social information processing (SIP) mediators of this effect. To explore whether persons with different SUD show idiosyncratic biases toward social signals, we administered an emotional go-nogo task (EGNG) to 31 individuals with Cocaine Use Disorder (CoUD), 31 with Cannabis Use Disorder (CaUD), 79 with Opioid Use Disorder (OUD), and 58 controls. Participants were instructed to respond to emotional faces (Fear/Happy) but withhold responses to expressionless faces in two task blocks, with the reverse instruction in the other two blocks. Emotional faces as non-targets elicited more "false alarm" (FA) commission errors as a main effect. Groups did not differ in overall rates of hits (correct responses to target faces), but participants with CaUD and CoUD showed reduced rates of hits (relative to controls) when expressionless faces were targets. OUD participants had worse hit rates [and slower reaction times (RT)] when fearful faces (but not happy faces) were targets. CaUD participants were most affected by instruction effects (respond/"go" vs withhold response/"no-go" to emotional face) on discriminability statistic A. Participants were faster to respond to happy face targets than to expressionless faces. However, this pattern was reversed in fearful face blocks in OUD and CoUD participants. This experiment replicated previous findings of the greater salience of expressive face images, and extends this finding to SUD, where persons with CaUD may show even greater bias toward emotional faces. Conversely, OUD participants showed idiosyncratic behavior in response to fearful faces suggestive of increased attentional disruption by fear. These data suggest a mechanism by which positive social signals may contribute to recovery.

Testing the factor structure underlying behavior using joint cognitive models: Impulsivity in delay discounting and Cambridge gambling tasks

Neurocognitive tasks are frequently used to assess disordered decision making, and cognitive models of these tasks can quantify performance in terms related to decision makers' underlying cognitive processes. In many cases, multiple cognitive models purport to describe similar processes, but it is difficult to evaluate whether they measure the same latent traits or processes. In this article, we develop methods for modeling behavior across multiple tasks by connecting cognitive model parameters to common latent constructs. This approach can be used to assess whether 2 tasks measure the same dimensions of cognition, or actually improve the estimates of cognitive models when there are overlapping cognitive processes between 2 related tasks. The approach is then applied to connecting decision data on 2 behavioral tasks that evaluate clinically relevant deficits, the delay discounting task and Cambridge gambling task, to determine whether they both measure the same dimension of impulsivity. We find that the discounting rate parameters in the models of each task are not closely related, although substance users exhibit more impulsive behavior on both tasks. Instead, temporal discounting on the delay discounting task as quantified by the model is more closely related to externalizing psychopathology like aggression, while temporal discounting on the Cambridge gambling task is related more to response inhibition failures. The methods we develop thus provide a new way to connect behavior across tasks and grant new insights onto the different dimensions of impulsivity and their relation to substance use. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Effects of Psychopathy on Neurocognitive Domains of Impulsivity in Abstinent Opiate and Stimulant Users

Background: Psychopathy and substance use disorders (SUDs) are both characterized by neurocognitive impairments reflecting higher levels of impulsivity such as reward-driven decision-making and deficient inhibitory control. Previous studies suggest that psychopathy may exacerbate decision-making deficits, but it may be unrelated to other neurocognitive impairments among substance dependent individuals (SDIs). The aim of the present study was to examine the role of psychopathy and its interpersonal-affective and impulsive-antisocial dimensions in moderating the relationships between dependence on different classes of drugs and neurocognitive domains of impulsivity. Method: We tested 693 participants (112 heroin mono-dependent individuals, 71 heroin polysubstance dependent individuals, 115 amphetamine mono-dependent individuals, 76 amphetamine polysubstance dependent individuals, and 319 non-substance dependent control individuals). Participants were administered the Psychopathy Checklist: Screening Version (PCL:SV) and seven neurocognitive tasks measuring impulsive choice/decision-making (Iowa Gambling Task; Cambridge Gambling Task; Kirby Delay Discounting Task; Balloon Analog Risk Task), and impulsive action/response inhibition (Go/No-Go Task, Immediate Memory Task, and Stop Signal Task). Results: A series of hierarchical multiple regressions revealed that the interpersonal-affective dimension of psychopathy moderated the association between decision-making, response inhibition and both amphetamine and heroin dependence, albeit differently. For amphetamine users, low levels of interpersonal-affective traits predicted poor decision-making on the Iowa Gambling Task and better response inhibition on the Stop Signal task. In contrast, in heroin users high interpersonal-affective psychopathy traits predicted lower risk taking on the Cambridge Gambling Task and better response inhibition on the Go/No-Go task. The impulsive-antisocial dimension of psychopathy predicted poor response inhibition in both amphetamine and heroin users. Conclusions: Our findings reveal that psychopathy and its dimensions had both common and unique effects on neurocognitive function in heroin and amphetamine dependent individuals. Our results suggest that the specific interactions between psychopathy dimensions and dependence on different classes of drugs may lead to either deficient or superior decision-making and response inhibition performance in SDIs, suggesting that psychopathy may paradoxically play a protective role for some neurocognitive functions in specific subtypes of substance users.

Validation of the Levenson Self-Report Psychopathy Scale in Bulgarian Substance-Dependent Individuals

The co-occurrence of psychopathy and substance use disorders (SUDs) is associated with higher relapse rates and increased risk of violent offending. Studies on the validity of psychopathy measures in community samples and substance-dependent individuals (SDIs) are scarce. The aim of the current study was to examine the psychometric properties of the Levenson Self-Report Psychopathy Scale (LSRP) in a sample of Bulgarian SDIs and non-dependent controls. We tested 615 participants: 106 heroin users, 91 amphetamine users, 123 polysubstance users, and 295 controls. Confirmatory factor analyses replicated the tri-factor structure of the LSRP (egocentric, antisocial, callous). The scale demonstrated acceptable reliability and validity. SDIs scored significantly higher than controls on the total scale and subscales of the LSRP, indicating good discriminant validity. Overall, results indicate that the LSRP is a valid instrument for measuring psychopathy in Bulgarian community samples.

Neurocognitive and Psychiatric Markers for Addiction: Common vs. Specific Endophenotypes for Heroin and Amphetamine Dependence

BACKGROUND

The differential utility of neurocognitive impulsivity and externalizing/ internalizing traits as putative endophenotypes for dependence on heroin vs. amphetamine is unclear.

OBJECTIVE

This exploratory study aims to determine: (1) whether neurocognitive impulsivity dimensions and externalizing/internalizing traits are correlated between siblings discordant for heroin and amphetamine dependence; and (2) which of these associations are common across substances and which are substance- specific.

METHODS

Pearson correlations between individuals with 'pure' heroin and amphetamine dependence and their unaffected biological siblings (n = 37 heroin sibling pairs; n = 30 amphetamine sibling pairs) were run on 10 neurocognitive measures, 6 externalizing measures, and 5 internalizing measures. Sibling pair effects were further examined using regression.

RESULTS

Siblings discordant for heroin dependence were significantly correlated on delay aversion on the Cambridge Gambling Task, risk-taking on the Balloon Analogue Risk Task, sensation seeking, and hopelessness. Siblings discordant for amphetamine dependence were significantly correlated on the quality of decision-making on the Cambridge Gambling Task, discriminability on the Immediate Memory Task, commission errors on the Go/No Go Task, trait impulsivity, ADHD and anxiety sensitivity.

CONCLUSION

Dimensions of impulsivity and externalizing/internalizing traits appear to aggregate among siblings discordant for substance dependence. Risk-taking propensity, sensation seeking and hopelessness were specific for heroin sibling pairs. Motor/action impulsivity, trait impulsivity, and anxiety sensitivity were specific to amphetamine sibling pairs. Decisional/choice impulsivity was common across both heroin and amphetamine sibling pairs. These findings provide preliminary evidence for the utility of neurocognitive impulsivity and externalizing/ internalizing traits as candidate endophenotypes for substance dependence in general and for substance-specific dependencies.

Relationships Between Alexithymia and Psychopathy in Heroin Dependent Individuals

BACKGROUND

Psychopathy and substance use disorders are highly co-morbid and their co-occurrence is associated with higher severity of addictive behavior and increased risk of violent offending. Both substance use disorders and psychopathy are related to prominent impairments in emotion processing, which are also central features of alexithymia. The nature of the relationship between psychopathy and alexithymia is not well-understood and has been particularly understudied among substance dependent individuals.

AIM

Our goal was to evaluate the levels of psychopathy and alexithymia in a relatively homogeneous sample of heroin dependent individuals (HDIs) and healthy controls and to examine group differences in the pattern of associations between these constructs.

METHODS

We examined 62 participants (31 heroin dependent individuals and 31 healthy controls) with the Psychopathy Checklist: Screening version (PCL:SV, Hart et al., 1995) and the Toronto Alexithymia Scale-20 (TAS-20, Bagby et al., 1994).

RESULTS

Heroin dependent individuals were characterized by higher levels of both psychopathy and alexithymia as compared to the control group. In addition, HDIs with higher levels of psychopathy reported more difficulties in identifying and verbalizing emotional states. In the heroin group, alexithymia was more strongly associated with the impulsive/antisocial characteristics (impulsivity, irresponsibility, antisocial behavior) than with the interpersonal/affective features of psychopathy (grandiosity, manipulativeness, lack of empathy, and remorse).

CONCLUSION

Our findings suggest that alexithymia may be one potential mechanism linking psychopathy with opioid use disorders. The development of interventions targeting alexithymia could have significant applications in relapse prevention programs and psychotherapy of substance use disorders with concurrent psychopathy.

Guidance on prevention of unintended and accidental radiation exposures in nuclear medicine

Nuclear medicine (NM) procedures for diagnosis and treatment of disease are performed routinely in hospitals throughout the world. These involve preparation and administration to patients of pharmaceuticals labelled with radioactive material. The International Atomic Energy Agency (IAEA) and the World Health Organisation highlighted the need for improvement in prevention of medical radiation incidents and accidents in the Bonn Call-for-Action in 2012. An IAEA Technical Meeting was held on prevention of unintended exposures and accidents in NM in 2018 to address the issue. Exposures can take place at any time when radioactive material is being produced and used, and the risk continues after procedures have been completed. Thus there is potential for staff or members of the general public to be exposed, as well as patients. This paper sets out guidelines for incident prevention based on presentations and discussions at the meeting, and review of reports from the literature. It deals with potential incidents in in-house radionuclide production, radiopharmaceutical preparation, administration to patients, and following a procedure, as well as aspects in management of radioactive materials. Special attention has been paid to therapeutic procedures, as these have the potential to cause more harm to patients from erroneous administrations, including tissue reactions from extravasation of radiopharmaceutical, and could lead to significant contamination events. Administration of NM therapy is generally contraindicated in pregnancy. Identification of any patient who may be pregnant is crucial and it might be necessary to verify this with a pregnancy test for patients within the age band considered to be fertile. Inclusion of NM therapy incidents in the IAEA automated reporting system SAFRON is recommended. In summary, the paper aims to highlight errors that could occur during different phases of NM procedures in order to aid prevention of incidents. The value of periodic audit in evaluating systems in place on a regular basis is emphasised. Approaches to incident investigation and follow-up are described, and the need to ensure corrective action is taken to address any deficiencies stressed.

Which features of psychopathy and impulsivity matter most for prison violence? New evidence among female prisoners

Prison violence is a complex and multifaceted phenomenon. While a great deal of research has been conducted in male samples, very few studies are dedicated to understanding violence committed by female offenders. Two constructs that have emerged as important predictors of violence are psychopathy and impulsivity. These constructs may be an important line of inquiry due to the close association between psychopathy, impulsivity, and violence. In a sample of 166 female offenders, we used the 3-facet model of psychopathy and 3-factor model of trait impulsivity with the goal to statistically explain two types of prison violence: official reports of violent misconducts over a 12-month period, and self-report of deliberately instigating a violent altercation. We conducted three separate regression models to test the independent contribution of psychopathy and impulsivity, as well as accounting for the overlap between psychopathy and impulsivity. When impulsivity and psychopathy were not competing within the same model, affective and behavioral psychopathic traits, and nonplanning impulsiveness predicted violent misconducts. However, when accounting for impulsivity and psychopathy within the same model, only affective psychopathic traits remained significant. When predicting if an offender deliberately started a violent altercation, separate statistical models showed affective and interpersonal psychopathic traits, and nonplanning impulsiveness were significant. When competing for variance within the same statistical model, only affective and interpersonal psychopathic traits remained as significant predictors. This suggests an overlap between psychopathic traits and nonplanning impulsivity when understanding violent misconducts in female offenders, while affective psychopathic explains female prison violence, regardless of impulsivity.

Sex differences on the four-facet model of psychopathy predict physical, verbal, and indirect aggression

Psychopathy is a multifaceted construct that has been linked to aggression. Yet, few studies have explored the association between physical, verbal, and indirect aggression using the 4-facet model of psychopathy in community samples, and to date, no studies exist that test for male and female differences. The present study aimed to understand what facets of psychopathy predict aggressive behavior for men and women, while controlling for important risk factors, such as Antisocial Personality Disorder (ASPD). Drawing from a large Bulgarian community sample (N = 565), a confirmatory factor analysis (CFA) supported the use of the 4-facet model of the Psychopathy Checklist: Screening Version (PCL:SV; Hart et al., ). Hierarchical linear regressions revealed that physical aggression was predicted by affective and antisocial psychopathic traits, and ASPD. Verbal aggression was predicted by the interpersonal facet, and indirect aggression was predicted by the antisocial psychopathy facet and ASPD. Sex significantly moderated the associations among facets of psychopathy and physical and indirect aggression. Specifically, the affective facet was positively associated with physical aggression only for women, whereas the antisocial facet was positively associated with indirect aggression only for men. Results suggest that the 4-facet model of psychopathy is sensitive to capture important similarities and differences between males and females when predicting forms of aggression in community samples. These findings underscore the importance of understanding how men and women differ in their risk-factors for aggressive behavior, which will better inform violence interventions based on sex-specific needs.

Impulsivities and addictions: a multidimensional integrative framework informing assessment and interventions for substance use disorders

Impulse control is becoming a critical survival skill for the twenty-first century. Impulsivity is implicated in virtually all externalizing behaviours and disorders, and figures prominently in the aetiology and long-term sequelae of substance use disorders (SUDs). Despite its robust clinical and predictive validity, the study of impulsivity is complicated by its multidimensional nature, characterized by a variety of trait-like personality dimensions, as well as by more state-dependent neurocognitive dimensions, with variable convergence across measures. This review provides a hierarchical framework for linking self-report and neurocognitive measures to latent constructs of impulsivity and, in turn, to different psychopathology vulnerabilities, including substance-specific addictions and comorbidities. Impulsivity dimensions are presented as novel behavioural targets for prevention and intervention. Novel treatment approaches addressing domains of impulsivity are reviewed and recommendations for future directions in research and clinical interventions for SUDs are offered. This article is part of the theme issue 'Risk taking and impulsive behaviour: fundamental discoveries, theoretical perspectives and clinical implications'.

Validation of the Substance Use Risk Profile Scale (SURPS) With Bulgarian Substance Dependent Individuals

Background: The Substance Use Risk Profile Scale (SURPS) is a 23-item self-report questionnaire that assesses four well-validated personality risk factors for substance misuse (Impulsivity, Sensation Seeking, Anxiety Sensitivity, and Hopelessness). While the SURPS has been used extensively with adolescents at risk for substance dependence, its properties with adult substance-dependent populations have been understudied. Further, the validity of the Bulgarian version of the SURPS has not been evaluated. The aims of the present study were to examine the factor structure of the Bulgarian version of the SURPS, its psychometric properties, and its ability to distinguish individuals with substance dependence from healthy controls. Methods: Participants included 238 individuals ages 18 to 50 (45% female): 36 "pure" (i.e., mono-substance dependent) heroin users, 34 "pure" amphetamine users, 32 polysubstance users, 64 controls with no history of substance dependence, 43 unaffected siblings of heroin users, and 29 unaffected siblings of amphetamine users. We explored the factor structure of the Bulgarian version of the SURPS with confirmatory factor analyses, examined its reliability and validity, and tested for group differences between substance dependent and non-dependent groups. Results: Confirmatory factor analyses (CFA) replicated the original four-factor model of the SURPS. The four subscales of the SURPS demonstrated good internal consistency (Cronbach's alphas ranged from 0.71 to 0.85) and adequate concurrent validity. Significant group differences were found on the Impulsivity and Sensation Seeking subscales, with the three substance dependent groups scoring higher than controls. Conclusions: The SURPS is a valid instrument for measuring personality risk for substance use disorders in the Bulgarian population. The Bulgarian version of the SURPS demonstrates adequate to good reliability, concurrent validity, and predictive validity. Its ability to distinguish between groups with and without a history of substance dependence was specific to externalizing traits such as Impulsivity and Sensation Seeking, on which opiate, stimulant, and polysubstance dependent individuals scored higher than non-dependent controls.

The Outcome-Representation Learning Model: A Novel Reinforcement Learning Model of the Iowa Gambling Task

The Iowa Gambling Task (IGT) is widely used to study decision-making within healthy and psychiatric populations. However, the complexity of the IGT makes it difficult to attribute variation in performance to specific cognitive processes. Several cognitive models have been proposed for the IGT in an effort to address this problem, but currently no single model shows optimal performance for both short- and long-term prediction accuracy and parameter recovery. Here, we propose the Outcome-Representation Learning (ORL) model, a novel model that provides the best compromise between competing models. We test the performance of the ORL model on 393 subjects' data collected across multiple research sites, and we show that the ORL reveals distinct patterns of decision-making in substance-using populations. Our work highlights the importance of using multiple model comparison metrics to make valid inference with cognitive models and sheds light on learning mechanisms that play a role in underweighting of rare events.

Fronto-striatal effective connectivity of working memory in adults with cannabis use disorder

Previous working memory (WM) studies found that relative to controls, subjects with cannabis use disorder (CUD) showed greater brain activation in some regions (e.g., left [L] and right [R] ventrolateral prefrontal cortex [VLPFC], and L dorsolateral prefrontal cortex [L-DLPFC]), and lower activation in other regions (e.g., R-DLPFC). In this study, effective connectivity (EC) analysis was applied to functional magnetic resonance imaging data acquired from 23 CUD subjects and 23 controls (two groups matched for sociodemographic factors and substance use history) while performing an n-back WM task with interleaved 2-back and 0-back periods. A 2-back minus 0-back modulator was defined to measure the modulatory changes of EC corresponding to the 2-back relative to 0-back conditions. Compared to the controls, the CUD group showed smaller modulatory change in the R-DLPFC to L-caudate pathway, and greater modulatory changes in L-DLPFC to L-caudate, R-DLPFC to R-caudate, and R-VLPFC to L-caudate pathways. Based on previous fMRI studies consistently suggesting that greater brain activations are related to a compensatory mechanism for cannabis neural effects (less regional brain activations), the smaller modulatory change in the R-DLPFC to L-caudate EC may be compensated by the larger modulatory changes in the other prefrontal-striatal ECs in the CUD individuals.

Testing associations between cannabis use and subcortical volumes in two large population-based samples

BACKGROUND AND AIMS

Disentangling the putative impact of cannabis on brain morphology from other comorbid substance use is critical. After controlling for the effects of nicotine, alcohol and multi-substance use, this study aimed to determine whether frequent cannabis use is associated with significantly smaller subcortical grey matter volumes.

DESIGN

Exploratory analyses using mixed linear models, one per region of interest (ROI), were performed whereby individual differences in volume (outcome) at seven subcortical ROIs were regressed onto cannabis and comorbid substance use (predictors).

SETTING

Two large population-based twin samples from the United States and Australia.

PARTICIPANTS

A total of 622 young Australian adults [66% female; μage  = 25.9, standard deviation SD) = 3.6] and 474 middle-aged US males (μage  = 56.1SD = 2.6 ) of predominately Anglo-Saxon ancestry with complete substance use and imaging data. Subjects with a history of stroke or traumatic brain injury were excluded.

MEASUREMENTS

Magnetic resonance imaging (MRI) and volumetric segmentation methods were used to estimate volume in seven subcortical ROIs: thalamus, caudate nucleus, putamen, pallidum, hippocampus, amygdala and nucleus accumbens. Substance use measurements included maximum nicotine and alcohol use, total life-time multi-substance use, maximum cannabis use in the young adults and regular cannabis use in the middle-aged males.

FINDINGS

After correcting for multiple testing (P = 0.007), cannabis use was unrelated to any subcortical ROI. However, maximum nicotine use was associated with significantly smaller thalamus volumes in middle-aged males.

CONCLUSIONS

In exploratory analyses based on young adult and middle-aged samples, normal variation in cannabis use is unrelated statistically to individual differences in brain morphology as measured by subcortical volume.

Collaboration, campaigns and champions for appropriate imaging: feedback from the Zagreb workshop

Abstract

Leading radiologists and representatives from national radiation protection regulatory authorities and health ministries from 19 countries of the European region worked together with five experts at the workshop on justification and appropriate use of imaging in Zagreb, Croatia, from 26 to 28 October 2017 jointly organised by the IAEA and the European Society of Radiology. The workshop served as a forum to exchange information on challenges and solutions for improving justification and the appropriate use of diagnostic imaging. Common barriers to improving the use of imaging referral guidelines were discussed and the need for increased collaboration identified. Examples of good practices were presented, including use of Clinical Decision Support (CDS) systems to facilitate rapid and good justification decisions. The workshop identified some of the needs of European countries for achieving more appropriate imaging proposing wider use of collaboration, campaigns and champions.

Main messages

• Drivers for appropriate imaging in Europe are similar to those elsewhere globally.

• Implementing imaging referral guidelines is the main barrier to more appropriate imaging.

• Clinical Decision Support systems (CDS) facilitates good referral practice and justification decisions.

• Collaboration, campaigns and champions may improve awareness, appropriateness and audit.

Decision-Making Under Risk, but Not Under Ambiguity, Predicts Pathological Gambling in Discrete Types of Abstinent Substance Users

This study explored how different forms of reward-based decision-making are associated with pathological gambling (PG) among abstinent individuals with prior dependence on different classes of drugs. Participants had lifetime histories of either "pure" heroin dependence (n = 64), "pure" amphetamine dependence (n = 51), or polysubstance dependence (n = 89), or had no history of substance dependence (n = 133). Decision-making was assessed via two neurocognitive tasks: (1) the Iowa Gambling Task (IGT), a measure of decision-making under ambiguity (i.e., uncertain risk contingencies); and (2) the Cambridge Gambling task (CGT), a measure of decision-making under risk (i.e., explicit risk contingencies). The main effects of neurocognitive performance and drug class on PG (defined as ≥3 DSM-IV PG symptoms) as well as their interactional effects were assessed via multiple linear regression. Two CGT indices of decision-making under risk demonstrated positive main effects on PG. Interaction effects indicated that the effects of decision-making under risk on PG were largely consistent across participant groups. Notably, a linear relationship between greater CGT Risk-Taking and PG symptoms was not observed among amphetamine users, whereas IGT performance was selectively and positively associated with PG in polysubstance users. Overall, results indicate that reward-based decision-making under risk may represent a risk factor for PG across substance users, with some variations in these relationships influenced by specific class of substance of abuse.

Lessons from two cases of radiation induced skin injuries in fluoroscopic procedures in Bulgaria

BACKGROUND

Radiation-induced injuries to patient skin as a result of fluoroscopy guided interventional procedures are infrequently reported, often misdiagnosed and there is a need to learn lessons from every injury.

METHODS

This paper describes two cases of radiation induced skin injuries that are, to the best of our knowledge, the first ever reported cases from Bulgaria and possibly from Eastern Europe, and would thus have educational value.

RESULTS

The important messages from the skin injuries reported here are: lack of awareness among part of the interventional specialists about the potential for radiation induced skin injury, misdiagnosis after injury happened because of lack of awareness and knowledge among general physicians, dermatologists and surgeons who followed up cases of skin injuries; the lack of system to monitor patients with relatively high exposure; the important role played by the medical physicist in diagnosing the injury and overall in initiating actions; the role of training and informational material displayed in interventional facilities.

CONCLUSIONS

For avoidance of skin injuries from interventional procedures it is of utmost importance to implement a system that includes (a) regular monitoring of radiation dose parameters of the procedure; (b) established trigger values for reporting;

Effects of sex and HIV serostatus on spatial navigational learning and memory among cocaine users

Spatial learning and memory are critically dependent on the integrity of hippocampal systems. Functional MRI and neuropathological studies show that hippocampal circuitry is prominently affected among HIV-seropositive individuals, but potential spatial learning and memory deficits have not been studied in detail in this population. We investigated the independent and interactive effects of sex and HIV serostatus on performance of a spatial learning and memory task in a sample of 181 individuals with a history of cocaine dependence. We found that men showed faster times to completion on immediate recall trials compared with women and that delayed recall was significantly poorer among HIV-infected compared with HIV-uninfected participants. Additionally, a sex × serostatus effect was found on the total number of completed learning trials. Specifically, HIV-infected men successfully completed more learning trials compared with HIV-infected women. Results are discussed in the context of recent reports of sex and HIV serostatus effects on episodic memory performance.

Sex differences in HIV effects on visual memory among substance-dependent individuals

HIV's effects on episodic memory have not been compared systematically between male and female substance-dependent individuals. We administered the Brief Visuospatial Memory Test-Revised (BVMT-R) to 280 substance-dependent HIV+ and HIV- men and women. Groups were comparable on demographic, substance use, and comorbid characteristics. There were no significant main effects of sex or HIV serostatus on BVMT-R performance, but HIV+ women performed significantly more poorly on delayed recall. This effect was most prominent among cocaine-dependent HIV+ women. Our findings are consistent with recent speculation that memory impairment may be more common among HIV+ women, particularly those with a history of cocaine dependence.

Unintended and accidental medical radiation exposures in radiology: guidelines on investigation and prevention

This paper sets out guidelines for managing radiation exposure incidents involving patients in diagnostic and interventional radiology. The work is based on collation of experiences from representatives of international and national organizations for radiologists, medical physicists, radiographers, regulators, and equipment manufacturers, derived from an International Atomic Energy Agency Technical Meeting. More serious overexposures can result in skin doses high enough to produce tissue reactions, in interventional procedures and computed tomography, most notably from perfusion studies. A major factor involved has been deficiencies in training of staff in operation of equipment and optimization techniques. The use of checklists and time outs before procedures commence, and dose alerts when critical levels are reached during procedures, can provide safeguards to reduce the risks of these effects occurring. However, unintended and accidental overexposures resulting in relatively small additional doses can take place in any diagnostic or interventional x-ray procedure and it is important to learn from errors that occur, as these may lead to increased risks of stochastic effects. Such events may involve the wrong examinations, procedural errors, or equipment faults. Guidance is given on prevention, investigation, and dose calculation for radiology exposure incidents within healthcare facilities. Responsibilities should be clearly set out in formal policies, and procedures should be in place to ensure that root causes are identified and deficiencies addressed. When an overexposure of a patient or an unintended exposure of a foetus occurs, the foetal, organ, skin, and/or effective dose may be estimated from exposure data. When doses are very low, generic values for the examination may be sufficient, but a full assessment of doses to all exposed organs and tissues may sometimes be required. The use of general terminology to describe risks from stochastic effects is recommended rather than the calculation of numerical values, as these are misleading when applied to individuals.

Sex and HIV serostatus differences in decision making under risk among substance-dependent individuals

HIV+ individuals with and without substance use disorders make significantly poorer decisions when information about the probability and magnitude of wins and losses is not available. We administered the Game of Dice Task, a measure of decision making under risk that provides this information explicitly, to 92 HIV+ and 134 HIV- substance-dependent men and women. HIV+ participants made significantly poorer decisions than HIV- participants, but this deficit appeared more prominent among HIV+ women. These data indicate that decision making under risk is impaired among HIV+ substance-dependent individuals (SDIs). Potential factors for the HIV+ women's relatively greater impairment are discussed.

Machine-learning identifies substance-specific behavioral markers for opiate and stimulant dependence

BACKGROUND

Recent animal and human studies reveal distinct cognitive and neurobiological differences between opiate and stimulant addictions; however, our understanding of the common and specific effects of these two classes of drugs remains limited due to the high rates of polysubstance-dependence among drug users.

METHODS

The goal of the current study was to identify multivariate substance-specific markers classifying heroin dependence (HD) and amphetamine dependence (AD), by using machine-learning approaches. Participants included 39 amphetamine mono-dependent, 44 heroin mono-dependent, 58 polysubstance dependent, and 81 non-substance dependent individuals. The majority of substance dependent participants were in protracted abstinence. We used demographic, personality (trait impulsivity, trait psychopathy, aggression, sensation seeking), psychiatric (attention deficit hyperactivity disorder, conduct disorder, antisocial personality disorder, psychopathy, anxiety, depression), and neurocognitive impulsivity measures (Delay Discounting, Go/No-Go, Stop Signal, Immediate Memory, Balloon Analogue Risk, Cambridge Gambling, and Iowa Gambling tasks) as predictors in a machine-learning algorithm.

RESULTS

The machine-learning approach revealed substance-specific multivariate profiles that classified HD and AD in new samples with high degree of accuracy. Out of 54 predictors, psychopathy was the only classifier common to both types of addiction. Important dissociations emerged between factors classifying HD and AD, which often showed opposite patterns among individuals with HD and AD.

CONCLUSIONS

These results suggest that different mechanisms may underlie HD and AD, challenging the unitary account of drug addiction. This line of work may shed light on the development of standardized and cost-efficient clinical diagnostic tests and facilitate the development of individualized prevention and intervention programs for HD and AD.

Neurocognitive and psychiatric dimensions of hot, but not cool, impulsivity predict HIV sexual risk behaviors among drug users in protracted abstinence

BACKGROUND

Impulsivity is an important risk factor for HIV risky drug and sexual behaviors. Research identifies hot (i.e. affectively-mediated, reward-based) and cool (motoric, attentional, independent of context) neurocognitive and psychiatric dimensions of impulsivity, though the impact of specific drugs of abuse on these varieties of impulsivity remains an open question.

OBJECTIVES

The present study examined the associations of neurocognitive and psychiatric varieties of hot and cool impulsivity with measures of lifetime and recent sexual risk behaviors among users of different classes of drugs.

METHODS

The study sample was comprised of drug users in protracted (> 1 year) abstinence: heroin mono-dependent (n = 61), amphetamine mono-dependent (n = 44), and polysubstance dependent (n = 73). Hot impulsivity was operationalized via neurocognitive tasks of reward-based decision-making and symptoms of psychopathy. Cool impulsivity was operationalized via neurocognitive tasks of response inhibition and symptoms of attention deficit/hyperactivity disorder (ADHD).

RESULTS

Hot impulsivity was associated with sexual risk behaviors among heroin and amphetamine users in protracted abstinence, whereas cool impulsivity was not associated with sexual risk behaviors among any drug-using group. Neurocognitive hot impulsivity was associated with recent (past 30-day) sexual risk behaviors, whereas psychopathy was associated with sexual risk behaviors during more remote time-periods (past 6 month and lifetime) and mediated the association between heroin dependence and past 6-month sexual risk behaviors.

CONCLUSION

Assessments and interventions aimed at reducing sexual risk behaviors among drug users should focus on hot neurocognitive and psychiatric dimensions of impulsivity, such as decision-making and psychopathy. Cool dimensions of impulsivity such as response inhibition and ADHD were not related to sexual risk behaviors among drug users in protracted abstinence.

Utility of Machine-Learning Approaches to Identify Behavioral Markers for Substance Use Disorders: Impulsivity Dimensions as Predictors of Current Cocaine Dependence

BACKGROUND

Identifying objective and accurate markers of cocaine dependence (CD) can innovate its prevention and treatment. Existing evidence suggests that CD is characterized by a wide range of cognitive deficits, most notably by increased impulsivity. Impulsivity is multidimensional and it is unclear which of its various dimensions would have the highest predictive utility for CD. The machine-learning approach is highly promising for discovering predictive markers of disease. Here, we used machine learning to identify multivariate predictive patterns of impulsivity phenotypes that can accurately classify individuals with CD.

METHODS

Current cocaine-dependent users (N = 31) and healthy controls (N = 23) completed the self-report Barratt Impulsiveness Scale-11 and five neurocognitive tasks indexing different dimensions of impulsivity: (1) Immediate Memory Task (IMT), (2) Stop-Signal Task, (3) Delay-Discounting Task (DDT), (4) Iowa Gambling Task (IGT), and (5) Probabilistic Reversal-Learning task. We applied a machine-learning algorithm to all impulsivity measures.

RESULTS

Machine learning accurately classified individuals with CD and predictions were generalizable to new samples (area under the curve of the receiver-operating characteristic curve was 0.912 in the test set). CD membership was predicted by higher scores on motor and non-planning trait impulsivity, poor response inhibition, and discriminability on the IMT, higher delay discounting on the DDT, and poor decision making on the IGT.

CONCLUSION

Our results suggest that multivariate behavioral impulsivity phenotypes can predict CD with high degree of accuracy, which can potentially be used to assess individuals' vulnerability to CD in clinical settings.