The Rehabilitation Potential of Neurostimulation for Mild Traumatic Brain Injury in Animal and Human Studies.

Neurostimulation carries high therapeutic potential, accompanied by an excellent safety profile. In this review, we argue that an arena in which these tools could provide breakthrough benefits is traumatic brain injury (TBI). TBI is a major health problem worldwide, with the majority of cases identified as mild TBI (mTBI). MTBI is of concern because it is a modifiable risk factor for dementia. A major challenge in studying mTBI is its inherent heterogeneity across a large feature space (e.g., etiology, age of injury, sex, treatment, initial health status, etc.). Parallel lines of research in human and rodent mTBI can be collated to take advantage of the full suite of neuroscience tools, from neuroimaging (electroencephalography: EEG; functional magnetic resonance imaging: fMRI; diffusion tensor imaging: DTI) to biochemical assays. Despite these attractive components and the need for effective treatments, there are at least two major challenges to implementation. First, there is insufficient understanding of how neurostimulation alters neural mechanisms. Second, there is insufficient understanding of how mTBI alters neural function. The goal of this review is to assemble interrelated but disparate areas of research to identify important gaps in knowledge impeding the implementation of neurostimulation.

Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network.

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

A meta-analysis of tract-based spatial statistics studies examining white matter integrity in cocaine use disorder.

Tract-based spatial statistics (TBSS) of diffusion tensor imaging (DTI) studies have consistently shown diminished white matter (WM) integrity for individuals with cocaine use disorder (CUD). The present study used seed-based d mapping (SDM) to determine the extent to which a systematic difference in the WM integrity of cocaine users may exist (as compared with that of healthy controls). Articles from 2006 (when TBSS was first developed) to present were reviewed, with eight selected for inclusion. Meta-analysis found lower fractional anisotropy (FA) in the genu of the corpus callosum for cocaine users, with a small-to-moderate peak effect size (Hedge's g = -0.331). Sensitivity analyses mostly supported the robustness of the obtained difference. Differences detected at exploratory thresholds for significance suggested insult to WM integrity extending beyond the corpus callosum. The present results compliment a previous region-of-interest (ROI)-based meta-analysis of DTI studies in individuals with CUD. These findings have significant implications for the potential role of neuroprotective agents in the treatment of CUD and merit additional iteration as more studies accrue in the literature.

Social Skills Training for Autism Spectrum Disorder: a Meta-analysis of In-person and Technological Interventions.

Social skills training (SST) for autism spectrum disorder (ASD) has traditionally focused on face-to-face (F2F-SST) interventions. Recently, Behavioral Intervention Technologies (BITs-SST) have been utilized to target social skills deficits using computer-based programs, avatars, and therapeutic robots. The present meta-analysis reviews recent evidence and compares the efficacy of 14 F2F-SST and four identified BITs-SST intervention trials for youth with ASD. These preliminary analyses did not indicate significant differences between F2F-SST and BITs-SST, with effect sizes consistently in the medium to high range (g = 0.81 and g = 0.93, respectively). These findings provide initial support for the continued investigation of BITs for providing SST to youth with ASD.

A preliminary cross-cultural study of Hikikomori and Internet Gaming Disorder: The moderating effects of game-playing time and living with parents.

BACKGROUND: Internet Gaming Disorder (IGD) and Hikikomori (an extreme form of social real-life withdrawal, where individuals isolate themselves from society) have both been suggested as mental disorders that require further clinical research, particularly among young adult populations. OBJECTIVE: To add to the extant literature, the present study used a cross-cultural, cross-sectional design to investigate the association between Hikikomori and IGD, and the potential moderating effects of reported game-playing time and living with parents. METHOD: Two online samples of 153 Australian and 457 U.S.-North American young adult players of Massively Multiplayer Online (MMO) games were collected. The nine-item Internet Gaming Disorder Scale-Short Form (IGDS-SF9), and the Hikikomori Social Withdrawal Scale were administered to dimensionally assess IGD and Hikikomori, respectively. RESULTS: Linear regression analyses confirmed that Hikikomori symptoms are associated with IGD. Additionally, moderation analyses indicated that the association was exacerbated by longer game playing time across both populations. Gamers living with their parents was a significant moderator of the relationship for the Australian sample. CONCLUSIONS: Extreme real-life social withdrawal and IGD are related, and this association is exacerbated for those who spend more time playing MMOs per day, and, for Australian participants, living with their parents.

Regional differences in white matter integrity in stimulant use disorders: A meta-analysis of diffusion tensor imaging studies.

BACKGROUND: Converging lines of evidence from diffusion tensor imaging (DTI) studies reveal significant alterations in white matter (WM) microstructure in the prefrontal cortex of chronic stimulant users compared to controls, suggesting compromised axonal microstructure and/or myelin. METHODS: A meta-analysis of DTI-based WM integrity was conducted for white matter regions across the corpus callosum and association fibers. Articles were sourced and selected using PRISMA guidelines for systematic review and meta-analysis. Inclusion and exclusion criteria were determined by the authors in order to best capture WM integrity among individuals with primary stimulant use in comparison to healthy control subjects. RESULTS: Eleven studies that focused on region-of-interest (ROI)-based analysis of WM integrity were extracted from an initial pool of 113 independent studies. Analysis across ROIs indicated significantly lower fractional anisotropy (FA) values in stimulant use groups compared to controls with a small to moderate overall effect (Hedges' g = -0.37, 95% CI [-0.54, -0.20]). Eigenvalues were also analyzed, revealing a significant effect for radial diffusivity (RD; Hedges' g = 0.24, 95% CI [0.01, 0.47]) but not axial diffusivity (AD; Hedges' g = 0.05, 95% CI [-0.20, 0.29]) or mean diffusivity (MD; Hedges' g = 0.20, 95% CI [-0.01, 0.41]). Subgroup analyses based on specific ROIs, primary substance use, poly-substance use, and imaging technology were also explored. CONCLUSION: Results of the present study suggest a consistent effect of compromised WM integrity for individuals with stimulant use disorders. Furthermore, no significant differences were found between cocaine and methamphetamine-based groups.

Assessing Online Flow Across Cultures: A Two-Fold Measurement Invariance Study.

The association between online Flow and Internet Gaming Disorder (IGD) has attracted significant attention. Despite the consensus that online Flow plays a pivotal role in the development of IGD and other Internet addictive behaviors, there has been a lack of consistency in measurement scales used to assess online Flow. Even widely used measures of online Flow have not been psychometrically assessed across culturally diverse populations of gamers. Such an assessment would enhance the accuracy of cross-cultural comparisons. Attending to this need, the present study assessed the psychometric properties of the binary coded (i.e., Yes, No) Online Flow Questionnaire (OFQ), while concurrently taking into consideration country, age, language, and mode of data collection (online or face-to-face) differences. Two sequences of successive multiple group confirmatory factor analyses were used to assess the psychometric properties of the OFQ, between: (a) emergent adults from the United States of America (N = 482, Mage = 25.23, SD = 2.746) and Australia (N = 168, Mage = 23.55, SD = 3.37) and (b) adolescents from Greece (N = 1579, Mage = 16.12, SD = 0.849) and Cyprus (N = 1372, Mage = 15.54, SD = 0.656). Configural and partial metric invariance were confirmed between the United States and Australian samples. For the Greek and Cypriot samples, results indicated full configural and metric invariance. These results provide initial information to researchers and clinicians of the extent to which the OFQ maintains its consistency when used across cultures and invite for further cross-cultural studies in the field. Implications, as well as limitations, are discussed.

Is the Sum Greater than its Parts? Variations in Substance-Related Consequences by Conjoint Alcohol-Marijuana Use Patterns.

Alcohol and marijuana are the most commonly used substances for college-attending young adults. This study evaluated differences in substance-specific consequence attribution by alcohol-marijuana use patterns (concurrent alcohol and marijuana [CAM; use of both substances, not at same time] and simultaneous [SAM; use of both, at same time]) as well as alcohol-only (AO). First-year college students with prior alcohol use (N = 610, 50.9% women, 71% White, Mage = 18) completed an online assessment of past-three-month substance use, including SAM, and related consequences. Results indicated that polydrug (SAM and CAM) users reported greater alcohol involvement and earlier alcohol initiation than AO, and polydrug use was associated with more alcohol-related problems, including sexual risk taking and alcohol-related blackouts. When restricted to SAM/CAM users, logistic regressions indicated that SAM users reported an increased incidence in two marijuana-related problems relative to CAM (driving after using and academic difficulties), but lower rates of social problems. SAM users were also less likely to attribute substance-related social problems to alcohol. Overall, findings highlight variations that exist within alcohol-marijuana polydrug users and show areas to consider for intervention development and future research.

Associations between attention deficit hyperactivity and internet gaming disorder symptoms: Is there consistency across types of symptoms, gender and countries?

BACKGROUND: Videogame addiction has been suggested as a tentative disorder in 2013 by the American Psychiatric Association (APA) and was recently officially recognized as a mental health disorder by the World Health Organization (WHO). Although a few studies have identified attention deficit and hyperactivity disorder (ADHD) as a key risk factor for Internet Gaming Disorder (IGD), the interplay between ADHD and IGD symptoms with gender differences across cultures remains to be further examined. OBJECTIVE: This study examined the moderating effects of gender in the association between ADHD and IGD across two nations. METHOD: A cross-sectional online survey was developed to recruit 164 Australian (Mage = 23.01, SD = 3.35, Minage = 18, Maxage = 31, Males n = 121, 73.80%) and 457 U.S.-North American (Mage = 25.25 years, SD = 2.76, Minage = 18 years, Maxage = 29 years, Males = 265, 57.98%) Massively Multiplayer Online (MMO) players aged between 18 and 29 years. RESULTS: The hierarchical linear regression, moderation and moderated moderation analyses revealed that participants presenting greater inattention and hyperactivity symptoms exhibited higher levels of IGD-related behaviors in the two samples. Moreover, these associations differed across genders between the two countries. Specifically, more hyperactive-impulsive, as well as inattentive males in the USA presented higher levels of disordered gaming. CONCLUSION: The results highlight the need for more cross-cultural and symptom-focused research in the broader IGD field.

Measurement Invariance of the Internet Gaming Disorder Scale-Short-Form (IGDS9-SF) Between Australia, the USA, and the UK.

The Internet Gaming Disorder Scale-Short-Form (IGDS9-SF) is widely used to assess Internet Gaming Disorder behaviors. Investigating cultural limitations and implications in its applicability is imperative. One way to evaluate the cross-cultural feasibility of the measure is through measurement invariance analysis. The present study used Multigroup Confirmatory Factor Analysis (MGCFA) to examine the IGDS9-SF measurement invariance across gamers from Australia, the United States of America (USA), and the United Kingdom (UK). To accomplish this, 171 Australian, 463 USA, and 281 UK gamers completed the IGDS9-SF. Although results supported the one-factor structure of the IGD construct, they indicated cross-country variations in the strength of the relationships between the indicators and their respective factor (i.e., non-invariant loadings of items 1, 2, 5), and that the same scores may not always indicate the same level of IGD severity across the three groups (i.e., non-invariant intercepts for items 1, 5, 7, 9).

Anorexia nervosa and bulimia nervosa: A meta-analysis of executive functioning.

OBJECTIVE: Research investigating the link between eating disorder (ED) diagnosis and executive dysfunction has had conflicting results, yet no meta-analyses have examined the overall association of ED pathology with executive functioning (EF). METHOD: Effect sizes were extracted from 32 studies comparing ED groups (27 of anorexia nervosa, 9 of bulimia nervosa) with controls to determine the grand mean effect on EF. Analyses included effects for individual EF measures, as well as an age-based subgroup analysis. RESULTS: There was a medium effect of ED diagnosis on executive functioning, with bulimia nervosa demonstrating a larger effect (Hedges's g=-0.70) than anorexia nervosa (g=-0.41). Within anorexia nervosa studies, subgroup analyses were conducted for age and diagnostic subtype. The effect of anorexia nervosa on EF was largest in adults; however, subgroup differences for age were not significant. CONCLUSIONS: Anorexia and bulimia nervosa are associated with EF deficits, which are particularly notable for individuals with bulimia nervosa. The present analysis includes recommendations for future studies regarding study design and EF measurement.

Age of Initiation and Internet Gaming Disorder: The Role of Self-Esteem.

The link between early initiation and problematic use has been observed for substance use disorders; however, this link has not been as clearly established for Internet gaming disorder (IGD). Available studies indicate that individuals who initiate Internet use at younger ages exhibit an increased risk for general Internet addiction. Prior research also suggests unique cognitive processes in online gaming, such that an individual's overall sense of self-worth can become contingent upon self-esteem derived from the gaming environment. The current research examines the mediational role of self-esteem variables in the relationship between age of initiation and IGD symptomatology. Data were analyzed from 1,044 adult participants (mean age = 30.90; standard deviation: 9.28; 35.0% female) recruited from Amazon Mechanical Turk who reported playing massively multiplayer online role-playing games. Age of gaming initiation is directly linked to IGD, as earlier age predicted overall IGD symptom severity (b = -0.10, 95% confidence interval [CI: -0.17, -0.03]), controlling for self-esteem factors. In addition, self-esteem factors emerged as mediators of the effect, where global self-esteem served as a protective factor (b = -0.05, 95% CI: [-0.07, -0.02]) and high gaming-contingent self-worth (GCSW; b = -0.10, 95% CI: [-0.15, -0.04]) was associated with more negative outcomes. Earlier age of gaming initiation is associated with IGD symptomatology. Although risks of screen time are often referred to in terms of physical consequences, the present study provides support regarding the inclusion of self-esteem factors in the link between early use and IGD.

The longitudinal association between anxiety and Internet addiction in adolescence: The moderating effect of classroom extraversion.

Background and aims The risk effect of anxiety on addictive behaviors, including Internet addiction (IA), has repeatedly been highlighted in the international literature. However, there is a lack of longitudinal studies examining this association in relation to proximal context effects, particularly in adolescence. Such findings would shed light on potential age- and proximal context-related variations in the anxiety-IA association that could better inform IA prevention and intervention initiatives. Methods In this study, 648 adolescents, embedded in 34 classrooms, were assessed at the age of 16 and again at the age of 18 to examine the effect of anxiety on IA behaviors in relation to the average level of classroom extraversion. IA was assessed with the Internet Addiction Test (Young, 1998), anxiety with the relevant subscale of the Symptom Checklist 90 - Revised (Derogatis & Savitz, 1999) and classroom extraversion with the synonymous subscale of the Five Factor Questionnaire (Asendorpf & van Aken, 2003). A three-level hierarchical linear model was calculated. Results The present findings demonstrated that: (a) higher levels of anxiety were significantly associated with higher IA behaviors, (b) the strength of this association did not vary over time (between 16 and 18 years old), and (c) however, it tended to weaken within classrooms higher in extraversion. Discussion This study indicated that the contribution of individual IA risk factors might differently unfold within different contexts.

Accuracy and Bias in Perceptions of Conflict Style Among Same-Sex and Heterosexual Couples.

Intimates form stable impressions of their romantic partner's conflict style, which may influence interactions during conflicts and shape expectancies regarding future disagreements. Despite a large body of work comparing relationship outcomes among heterosexual and same-sex couples, research has yet to examine how the validity of these perceptions vary as a function of gender and sexual orientation. The present study examines perceptual accuracy and bias in perceptions of conflict style among same-sex female (Ndyads=215), same-sex male (Ndyads=113), and heterosexual (Ndyads=93) couples. Although members of same-sex and heterosexual couples exhibited some similarity in accuracy and bias in perceptions, a number of compelling differences suggest that the gender and the sexual orientation of a couple shape perceptions of partner conflict style.