The Effects of a Single Transcranial Direct Current Stimulation Session on Impulsivity and Risk Among a Sample of Adult Recreational Cannabis Users

Individuals with substance use disorders exhibit risk-taking behaviors, potentially leading to negative consequences and difficulty maintaining recovery. Non-invasive brain stimulation techniques such as transcranial direct current stimulation (tDCS) have yielded mixed effects on risk-taking among healthy controls. Given the importance of risk-taking behaviors among substance-using samples, this study aimed to examine the effects of tDCS on risk-taking among a sample of adults using cannabis. Using a double-blind design, 27 cannabis users [M(SD) age = 32.48 (1.99), 41% female] were randomized, receiving one session of active or sham tDCS over the bilateral dorsolateral prefrontal cortex (dlPFC). Stimulation parameters closely followed prior studies with anodal right dlPFC and cathodal left dlPFC stimulation. Risk-taking—assessed via a modified Cambridge Gambling Task—was measured before and during tDCS. Delay and probability discounting tasks were assessed before and after stimulation. No significant effects of stimulation on risk-taking behavior were found. However, participants chose the less risky option ∼86% of the trials before stimulation which potentially contributed to ceiling effects. These results contradict one prior study showing increased risk-taking among cannabis users following tDCS. There was a significant increase in delay discounting of a $1000 delayed reward during stimulation for the sham group only, but no significant effects for probability discounting. The current study adds to conflicting and inconclusive literature on tDCS and cognition among substance-using samples. In conclusion, results suggest the ineffectiveness of single session dlPFC tDCS using an established stimulation protocol on risk-taking, although ceiling effects at baseline may have also prevented behavior change following tDCS

Dissociative symptomatology mediates the relation between posttraumatic stress disorder severity and alcohol-related problems

Background: Up to 50% of individuals with posttraumatic stress disorder (PTSD) endorse problematic alcohol use. Typically, these individuals present with more complex and often more severe PTSD symptoms than those who do not report problematic alcohol use. Emerging literature suggests that heightened symptoms of dissociation are likewise associated with greater PTSD symptom severity. Despite this knowledge, the role of dissociation in the relation between PTSD severity and alcohol-related problems has yet to be examined. Here, we explore the mediating role of dissociative symptomatology on the association between PTSD severity and alcohol-related problems within a PTSD treatment-seeking sample. Methods: Structural equation modeling was used to test the mediating role of dissociative symptomatology between PTSD severity and alcohol-related problems. Participants [N = 334; mean age (SD) = 44.29 (9.77), 50% female] were drawn from a clinical intake battery database for PTSD in-patient treatment services at Homewood Health Care, Guelph, ON, Canada. A subset of battery measures assessing PTSD severity, dissociative symptomatology, and alcohol-related problems were submitted to analysis. Results: A significant positive association emerged between PTSD severity and alcohol-related problems (β = 0.127, p \u3c 0.05) in the absence of dissociative symptomatology. Critically, however, when added to this model, dissociative symptomatology (six unique facets of dissociation assessed by the Multiscale Dissociation Inventory) mediated the relation between PTSD severity and alcohol-related problems. Specifically, greater PTSD severity was associated with greater dissociative symptomatology (β = 0.566, p \u3c 0.0001), which was in turn associated with greater alcohol-related problems (β = 0.184, p \u3c 0.05). Conclusions: These results suggest that dissociative symptomatology plays a key role in explaining the relation between PTSD severity and alcohol-related problems. Future studies should examine the impact of targeting dissociative symptomatology specifically in treating individuals with PTSD who endorse alcohol-related problems

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

Application of infrared thermography in computer aided diagnosis

The invention of thermography, in the 1950s, posed a formidable problem to the research community: What is the relationship between disease and heat radiation captured with Infrared (IR) cameras? The research community responded with a continuous effort to find this crucial relationship. This effort was aided by advances in processing techniques, improved sensitivity and spatial resolution of thermal sensors. However, despite this progress fundamental issues with this imaging modality still remain. The main problem is that the link between disease and heat radiation is complex and in many cases even non-linear. Furthermore, the change in heat radiation as well as the change in radiation pattern, which indicate disease, is minute. On a technical level, this poses high requirements on image capturing and processing. On a more abstract level, these problems lead to inter-observer variability and on an even more abstract level they lead to a lack of trust in this imaging modality. In this review, we adopt the position that these problems can only be solved through a strict application of scientific principles and objective performance assessment. Computing machinery is inherently objective; this helps us to apply scientific principles in a transparent way and to assess the performance results. As a consequence, we aim to promote thermography based Computer-Aided Diagnosis (CAD) systems. Another benefit of CAD systems comes from the fact that the diagnostic accuracy is linked to the capability of the computing machinery and, in general, computers become ever more potent. We predict that a pervasive application of computers and networking technology in medicine will help us to overcome the shortcomings of any single imaging modality and this will pave the way for integrated health care systems which maximize the quality of patient care

Income shock increases preferences for smaller immediate rewards and reduces alcohol demand among a sample of crowd-sourced adults.

In behavioral economics, income shock manipulations (hypothetical narratives where money is gained or lost) can provide meaningful insight into decision-making related to primary and secondary commodities. To date, few studies have examined the impact of income shock on delay discounting in healthy controls and individuals using substances, and no study to date has examined the impact of income shock on alcohol demand. This study examined the effects of income shock on behavioral economic assessments (i.e., delay discounting and alcohol demand) among a sample of adult participants recruited via Amazon Mechanical Turk (N = 140). The sample was predominantly middle-aged, male, and White (mean age = 38.81; 37.1% female; 77.1% White). Participants were randomly assigned to one of three income shock narratives (negative, neutral, positive). They completed two versions of the 5-choice delay discounting task for $100 and$1,000 and an alcohol purchase task (APT) before and after the income shock narrative. Following negative income shock, preferences for smaller immediate rewards increased in the $100 version of the discounting task and decreased the price at which alcohol consumption was suppressed to zero (i.e., break point). Sensitivity to price changes in the APT decreased following neutral and positive income shock but not the negative condition. Results replicate and extend prior findings examining the impact of income shock on delay discounting. Furthermore, this is the first study to study income shock effects on alcohol demand. Findings suggest that primary commodity manipulation (i.e., money) can potentially impact decision-making regarding secondary commodities (i.e., alcohol). (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Do traumatic events and substance use co-occur during adolescence? Testing three causal etiologic hypotheses

Background. Why do potentially traumatic events (PTEs) and substance use (SU) so commonly co-occur during adolescence? Causal hypotheses developed from the study of posttraumatic stress disorder (PTSD) and substance use disorder (SUD) among adults have not yet been subject to rigorous theoretical analysis or empirical tests among adolescents with the precursors to these disorders: PTEs and SU. Establishing causality demands accounting for various factors (e.g., genetics, socioeconomic status, race/ethnicity) that distinguish youth endorsing PTEs and SU from those who do not, a step often overlooked in previous research. Methods. We leveraged nationwide data from a sociodemographically diverse sample of youth (N = 11,468) in the Adolescent Brain and Cognitive Development (ABCD) Study. PTEs and drinking prevalence were assessed annually. To account for the many pre-existing differences between youth with and without PTE/SU (i.e., confounding bias) and provide rigorous tests of causal hypotheses, we linked within-person changes in PTEs and SU (alcohol, cannabis, nicotine) across repeated measurements and adjusted for time-varying factors (e.g., age, internalizing symptoms, externalizing symptoms, and friends' use of substances). Results . Before adjusting for confounding using within-person modeling, PTEs and SU exhibited significant concurrent associations (βs=.46–1.26, ps&lt;.05) and PTEs prospectively predicted greater SU (βs=.55–1.43, ps&lt;.05) but not vice versa. After adjustment for confounding, the PTEs exhibited significant concurrent associations for alcohol (βs=.15–.22, ps&lt;.05) but not cannabis or nicotine (βs=.01–.12, ps&gt;.05) and PTEs prospectively predicted greater SU (βs=.28–.55, ps&gt;.05) but not vice versa. Conclusions. When tested rigorously in a nationwide sample of adolescents, we find support for a model in which PTE is followed by SU but not for a model in which SU is followed by PTEs. Explanations for why PTSD and SUD co-occur in adults may need further theoretical analysis and adaptation before extension to adolescents

A Comparison of Remote Versus In-Person Assessments of Substance Use and Related Constructs Among Adolescents

Objective. Underreporting of adolescent substance use is a known issue, with format of assessment (in-person vs. remote) a potentially important factor. We investigate whether being assessed remotely (via phone or videoconference) versus in-person affects youth report of substance use patterns, attitudes, and access, hypothesizing remote visits would garner higher levels of substance use reporting and more positive substance use attitudes. Methods. We used the Adolescent Brain and Cognitive Development SM [ABCD] Study data between 2021-2022 during the COVID-19 pandemic. Participants chose whether to complete assessments in-person (n=615; 49% female; mean age=13.9; 57% White) or remotely (n=1,467; 49% female, mean age=13.7; 49% White). Regressions predicted substance use patterns, attitudes, and access, by visit format, controlling for relevant sociodemographic factors. Effect sizes and standardized mean differences are presented. Results. While 17% of adolescent participants reported any level of substance use, those queried remotely were less likely to endorse use (OR=0.76, p=.04), sipping alcohol (OR=0.78, p=.08), or eating cannabis (OR=0.51, p=.05). Similarly, youth interviewed remotely reported less curiosity or intent to try alcohol, and more negative attitudes and expectancies around alcohol and, at times, cannabis use, with small to medium effect sizes. Conclusions. Preliminary evidence suggests youth completing remote visits were less likely to disclose any substance use, less e-cigarette access, less curiosity or intent to use alcohol, and more negative attitudes toward alcohol and cannabis. Notably, effect sizes were modest. Thus, format of substance use assessment should be controlled for, but balanced by other study needs (e.g., increasing accessibility of research to all sociodemographic groups)

Digital Location Tracking of Children and Adolescents: A Review and Theoretical Model

Many parents in the U.S. have begun using GPS-based digital location tracking (DLT) technologies (smartphones, tags, wearables) to track the whereabouts of children and adolescents. This paper reviews the literature to determine what is known about DLT today. We find that there is minimal published data on DLT. There are 5 quantitative studies, all cross-sectional, most of which report only the prevalence of DLT use or the apps used (1 study has reported on correlates). Most published articles on DLT are commentary papers or small qualitative studies addressing the new ethical, developmental, and sociocultural issues that arise from DLT use (e.g., consent, privacy, autonomy, independence). These articles are primarily speculative, rather than representative surveys of what youth and parents actually think or do. Thus, DLT comprises a vastly understudied parenting behavior of developmental and clinical relevance. To stimulate further research, we propose a theoretical model that situates DLT in the more mature literatures on parental monitoring and youth information management

Digital Location Tracking of Children and Adolescents: A Review and Theoretical Model

Many parents in the U.S. have begun using GPS-based digital location tracking (DLT) technologies (smartphones, tags, wearables) to track the whereabouts of children and adolescents. This paper reviews the literature to determine what is known about DLT today. We find that there is minimal published data on DLT. There are 5 quantitative studies, all cross-sectional, most of which report only the prevalence of DLT use or the apps used (1 study has reported on correlates). Most published articles on DLT are commentary papers or small qualitative studies addressing the new ethical, developmental, and sociocultural issues that arise from DLT use (e.g., consent, privacy, autonomy, independence). These articles are primarily speculative, rather than representative surveys of what youth and parents actually think or do. Thus, DLT comprises a vastly understudied parenting behavior of developmental and clinical relevance. To stimulate further research, we propose a theoretical model that situates DLT in the more mature literatures on parental monitoring and youth information management