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This study examines the prospective associations of alcohol and drug misuse with suicidal behaviors among service members who have left active duty. We also evaluate potential moderating effects of other risk factors and whether substance misuse signals increased risk of transitioning from thinking about to attempting suicide.
Method
US Army veterans and deactivated reservists (N = 6,811) completed surveys in 2016–2018 (T1) and 2018–2019 (T2). Weights-adjusted logistic regression was used to estimate the associations of binge drinking, smoking/vaping, cannabis use, prescription drug abuse, illicit drug use, alcohol use disorder (AUD), and drug use disorder (DUD) at T1 with suicide ideation, plan, and attempt at T2. Interaction models tested for moderation of these associations by sex, depression, and recency of separation/deactivation. Suicide attempt models were also fit in the subgroup with ideation at T1 (n = 1,527).
Results
In models controlling for socio-demographic characteristics and prior suicidality, binge drinking, cannabis use, prescription drug abuse, illicit drug use, and AUD were associated with subsequent suicidal ideation (AORs = 1.42–2.60, ps < .01). Binge drinking, AUD, and DUD were associated with subsequent suicide plan (AORs = 1.23–1.95, ps < .05). None of the substance use variables had a main effect on suicide attempt; however, interaction models suggested certain types of drug use predicted attempts among those without depression. Additionally, the effects of smoking/vaping and AUD differed by sex. Substance misuse did not predict the transition from ideation to attempt.
Conclusions
Alcohol and drug misuse are associated with subsequent suicidal behaviors in this population. Awareness of differences across sex and depression status may inform suicide risk assessment.
Racial and ethnic variations in antibiotic utilization are well-reported in outpatient settings but little is known about inpatient settings. Our objective was to describe national inpatient antibiotic utilization among children by race and ethnicity.
Methods:
This study included hospital visit data from the Pediatric Health Information System between 01/01/2022 and 12/31/2022 for patients <20 years. Primary outcomes were the percentage of hospitalization encounters that received an antibiotic and antibiotic days of therapy (DOT) per 1000 patient days. Mixed-effect regression models were used to determine the association of race-ethnicity with outcomes, adjusting for covariates.
Results:
There were 846,530 hospitalizations. 45.2% of children were Non-Hispanic (NH) White, 27.1% were Hispanic, 19.2% were NH Black, 4.5% were NH Other, 3.5% were NH Asian, 0.3% were NH Native Hawaiian/Other Pacific Islander (NHPI) and 0.2% were NH American Indian. Adjusting for covariates, NH Black children had lower odds of receiving antibiotics compared to NH White children (aOR 0.96, 95%CI 0.94–0.97), while NH NHPI had higher odds of receiving antibiotics (aOR 1.16, 95%CI 1.05–1.29). Children who were Hispanic, NH Asian, NH American Indian, and children who were NH Other received antibiotic DOT compared to NH White children, while NH NHPI children received more antibiotic DOT.
Conclusions:
Antibiotic utilization in children’s hospitals differs by race and ethnicity. Hospitals should assess policies and practices that may contribute to disparities in treatment; antibiotic stewardship programs may play an important role in promoting inpatient pharmacoequity. Additional research is needed to examine individual diagnoses, clinical outcomes, and drivers of variation.
Identifying persons with HIV (PWH) at increased risk for Alzheimer’s disease (AD) is complicated because memory deficits are common in HIV-associated neurocognitive disorders (HAND) and a defining feature of amnestic mild cognitive impairment (aMCI; a precursor to AD). Recognition memory deficits may be useful in differentiating these etiologies. Therefore, neuroimaging correlates of different memory deficits (i.e., recall, recognition) and their longitudinal trajectories in PWH were examined.
Design:
We examined 92 PWH from the CHARTER Program, ages 45–68, without severe comorbid conditions, who received baseline structural MRI and baseline and longitudinal neuropsychological testing. Linear and logistic regression examined neuroanatomical correlates (i.e., cortical thickness and volumes of regions associated with HAND and/or AD) of memory performance at baseline and multilevel modeling examined neuroanatomical correlates of memory decline (average follow-up = 6.5 years).
Results:
At baseline, thinner pars opercularis cortex was associated with impaired recognition (p = 0.012; p = 0.060 after correcting for multiple comparisons). Worse delayed recall was associated with thinner pars opercularis (p = 0.001) and thinner rostral middle frontal cortex (p = 0.006) cross sectionally even after correcting for multiple comparisons. Delayed recall and recognition were not associated with medial temporal lobe (MTL), basal ganglia, or other prefrontal structures. Recognition impairment was variable over time, and there was little decline in delayed recall. Baseline MTL and prefrontal structures were not associated with delayed recall.
Conclusions:
Episodic memory was associated with prefrontal structures, and MTL and prefrontal structures did not predict memory decline. There was relative stability in memory over time. Findings suggest that episodic memory is more related to frontal structures, rather than encroaching AD pathology, in middle-aged PWH. Additional research should clarify if recognition is useful clinically to differentiate aMCI and HAND.
Many people with HIV (PWH) are at risk for age-related neurodegenerative disorders such as Alzheimer’s disease (AD). Studies on the association between cognition, neuroimaging outcomes, and the Apolipoprotein E4 (APOE4) genotype, which is associated with greater risk of AD, have yielded mixed results in PWH; however, many of these studies have examined a wide age range of PWH and have not examined APOE by race interactions that are observed in HIV-negative older adults. Thus, we examined how APOE status relates to cognition and medial temporal lobe (MTL) structures (implicated in AD pathogenesis) in mid- to older-aged PWH. In exploratory analyses, we also examined race (African American (AA)/Black and non-Hispanic (NH) White) by APOE status interactions on cognition and MTL structures.
Participants and Methods:
The analysis included 88 PWH between the ages of 45 and 68 (mean age=51±5.9 years; 86% male; 51% AA/Black, 38% NH-White, 9% Hispanic/Latinx, 2% other) from the CNS HIV Antiretroviral Therapy Effects Research multi-site study. Participants underwent APOE genotyping, neuropsychological testing, and structural MRI; APOE groups were defined as APOE4+ (at least one APOE4 allele) and APOE4- (no APOE4 alleles). Eighty-nine percent of participants were on antiretroviral therapy, 74% had undetectable plasma HIV RNA (<50 copies/ml), and 25% were APOE4+ (32% AA/Black/15% NH-White). Neuropsychological testing assessed seven domains, and demographically-corrected T-scores were calculated. FreeSurfer 7.1.1 was used to measure MTL structures (hippocampal volume, entorhinal cortex thickness, and parahippocampal thickness) and the effect of scanner was regressed out prior to analyses. Multivariable linear regressions tested the association between APOE status and cognitive and imaging outcomes. Models examining cognition covaried for comorbid conditions and HIV disease characteristics related to global cognition (i.e., AIDS status, lifetime methamphetamine use disorder). Models examining the MTL covaried for age, sex, and
relevant imaging covariates (i.e., intracranial volume or mean cortical thickness).
Results:
APOE4+ carriers had worse learning (ß=-0.27, p=.01) and delayed recall (ß=-0.25, p=.02) compared to the APOE4- group, but APOE status was not significantly associated with any other domain (ps>0.24). APOE4+ status was also associated with thinner entorhinal cortex (ß=-0.24, p=.02). APOE status was not significantly associated with hippocampal volume (ß=-0.08, p=0.32) or parahippocampal thickness (ß=-0.18, p=.08). Lastly, race interacted with APOE status such that the negative association between APOE4+ status and cognition was stronger in NH-White PWH as compared to AA/Black PWH in learning, delayed recall, and verbal fluency (ps<0.05). There were no APOE by race interactions for any MTL structures (ps>0.10).
Conclusions:
Findings suggest that APOE4 carrier status is associated with worse episodic memory and thinner entorhinal cortex in mid- to older-aged PWH. While APOE4+ groups were small, we found that APOE4 carrier status had a larger association with cognition in NH-White PWH as compared to AA/Black PWH, consistent with studies demonstrating an attenuated effect of APOE4 in older AA/Black HIV-negative older adults. These findings further highlight the importance of recruiting diverse samples and suggest exploring other genetic markers (e.g., ABCA7) that may be more predictive of AD in some races to better understand AD risk in diverse groups of PWH.
Background: The presence of intraluminal thrombi (ILT) in acutely symptomatic carotid stenosis (“hot carotid”) represents a therapeutic dilemma for physicians. With little evidence to guide treatment, current ILT management approaches rely on individual or institutional preferences. Methods: This mixed methods study analyzed themes from semi-structured interviews with 22 stroke physicians from 16 centers, paired with a worldwide case-based survey of 628 stroke physicians conducted through the “Practice Current” section of Neurology: Clinical Practice. Results: In the thematic analysis of the interviews and quantitative analysis of the survey, participants favoured using anticoagulation with or without antiplatelet agents in patients with ILT (463/628, 74%). Despite a preference for anticoagulation, uncertainty regarding optimal antithrombotic management was noted in the thematic analysis. Additional themes identified included a preference for re-imaging patients in 3-5 days after initiating treatment to look for complete or partial clot resolution, at which point most experts would then be comfortable proceeding with revascularization if indicated, though uncertainty regarding the optimal timing of revascularization was noted. Conclusions: In cases of ILT in the “hot carotid” practice patterns of global experts show a preference for using anticoagulation and reimaging patients in 3-5 days, though there is considerable equipoise regarding the most appropriate management of these patients.
Background: Little evidence exists to guide the management of symptomatic non-stenotic carotid disease (SyNC). SyNC, which refers to carotid lesions with less than 50% artery stenosis, has been increasingly implicated as a cause of stroke and TIA. Methods: Semi-structured interviews with 22 stroke physicians from 16 centers were conducted as part of the Hot Carotid Qualitative Study. This study explored decision-making approaches, opinions and attitudes regarding the management of symptomatic carotid disease. Presented here are a subset of results related to the decision to revascularize patients with SyNC. Results: Thematic analysis revealed equipoise in the decision to revascularize patients with SyNC. Participants discussed a desire to use imaging features (e.g plaque rupture and plaque morphology) to inform the decision to revascularize, though significant uncertainty remains in appraising the risk conferred by certain features. Experts support further study to better understand the use of these features in risk appraisal for patients with SyNC. Conclusions: The decision to revascularize patients with SyNC is an area with significant equipoise. Experts identify the use of imaging features as an important tool in informing the decision to pursue revascularization in patients with SyNC though more study is required in this area to better inform practice.
Identification of genetic risk factors may inform the prevention and treatment of posttraumatic stress disorder (PTSD). This study evaluates the associations of polygenic risk scores (PRS) with patterns of posttraumatic stress symptoms following combat deployment.
Method
US Army soldiers of European ancestry (n = 4900) provided genomic data and ratings of posttraumatic stress symptoms before and after deployment to Afghanistan in 2012. Latent growth mixture modeling was used to model posttraumatic stress symptom trajectories among participants who provided post-deployment data (n = 4353). Multinomial logistic regression models tested independent associations between trajectory membership and PRS for PTSD, major depressive disorder (MDD), schizophrenia, neuroticism, alcohol use disorder, and suicide attempt, controlling for age, sex, ancestry, and exposure to potentially traumatic events, and weighted to account for uncertainty in trajectory classification and missing data.
Results
Participants were classified into low-severity (77.2%), increasing-severity (10.5%), decreasing-severity (8.0%), and high-severity (4.3%) posttraumatic stress symptom trajectories. Standardized PTSD-PRS and MDD-PRS were associated with greater odds of membership in the high-severity v. low-severity trajectory [adjusted odds ratios and 95% confidence intervals, 1.23 (1.06–1.43) and 1.18 (1.02–1.37), respectively] and the increasing-severity v. low-severity trajectory [1.12 (1.01–1.25) and 1.16 (1.04–1.28), respectively]. Additionally, MDD-PRS was associated with greater odds of membership in the decreasing-severity v. low-severity trajectory [1.16 (1.03–1.31)]. No other associations were statistically significant.
Conclusions
Higher polygenic risk for PTSD or MDD is associated with more severe posttraumatic stress symptom trajectories following combat deployment. PRS may help stratify at-risk individuals, enabling more precise targeting of treatment and prevention programs.
Personality traits (e.g. neuroticism) and the social environment predict risk for internalizing disorders and suicidal behavior. Studying these characteristics together and prospectively within a population confronted with high stressor exposure (e.g. U.S. Army soldiers) has not been done, yet could uncover unique and interactive predictive effects that may inform prevention and early intervention efforts.
Methods
Five broad personality traits and social network size were assessed via self-administered questionnaires among experienced soldiers preparing for deployment (N = 4645) and new soldiers reporting for basic training (N = 6216). Predictive models examined associations of baseline personality and social network variables with recent distress disorders or suicidal behaviors assessed 3- and 9-months post-deployment and approximately 5 years following enlistment.
Results
Among the personality traits, elevated neuroticism was consistently associated with increased mental health risk following deployment. Small social networks were also associated with increased mental health risk following deployment, beyond the variance accounted for by personality. Limited support was found for social network size moderating the association between personality and mental health outcomes. Small social networks also predicted distress disorders and suicidal behavior 5 years following enlistment, whereas unique effects of personality traits on these more distal outcomes were rare.
Conclusions
Heightened neuroticism and small social networks predict a greater risk for negative mental health sequelae, especially following deployment. Social ties may mitigate adverse impacts of personality traits on psychopathology in some contexts. Early identification and targeted intervention for these distinct, modifiable factors may decrease the risk of distress disorders and suicidal behavior.
Background: There are uncertainties regarding the optimal management of acutely symptomatic carotid stenosis (“hot carotids”). We sought to explore the approaches of stroke physicians to anti-thrombotic management, imaging, and revascularization in patients with “hot carotids”. Methods: We used a qualitative descriptive methodology to examine decision-making approaches of physicians regarding the management of hot carotids. We conducted semi-structured interviews with 22 stroke physicians from various specialties in 16 centers across 4 continents. Results: Important themes regarding anti-thrombotic included limitations of existing clinical trial evidence, competing physician preferences, antiplatelet therapy while awaiting revascularization and various regional differences. Timely imaging availability, breadth of information gained, and surgeon/interventionalist preferences were important themes influencing the choice of imaging modality. The choice of revascularization intervention was influenced by healthcare system factors such as use of multidisciplinary review and operating room/angiography suite availability, and patient factors like age and infarct size. Many themes related to uncertainties in the management of hot carotids were also discussed. Conclusions: Our study revealed themes that are important to international stroke experts. We highlight common and divergent practices while underscoring important areas of clinical equipoise and uncertainty. Teams designing international carotid trials may wish to accommodate identified variations in practice patterns and areas of uncertainty.
In this pre- and postintervention study, we demonstrate the feasibility and effectiveness of comprehensive simulation-based personal protective equipment (PPE) training amid the COVID-19 pandemic. With rapid-cycle, deliberate practice feedback, simulation-based training can improve the learners’ sense of confidence and security while standardizing PPE protocols.
To perform a review of the literature on the role of simulation-based training (SBT) in healthcare-associated infection (HAI) prevention and to highlight the importance of SBT as an educational tool in infection prevention.
Methods:
We reviewed English language publications from PubMed to select original articles that utilized SBT as the primary mode of education for infection prevention efforts in acute-care hospitals.
Results:
Overall, 27 publications utilized SBT as primary mode of education for HAI prevention in acute-care hospitals. Training included the following: hand hygiene in 3 studies (11%), standard precaution in 1 study (4%), disaster preparedness in 4 studies (15%), central-line–associated blood stream infection (CLABSI) prevention in 14 studies (52%), catheter-associated urinary tract infection (CAUTI) prevention in 2 studies (7%), surgical site infection prevention in 2 studies (7%), and ventilatory associated pneumonia prevention in 1 study (4%). SBT improved learner’s sense of competence and confidence, increased knowledge and compliance in infection prevention measures, decreased HAI rates, and reduced healthcare costs.
Conclusion:
SBT can function as a teaching tool in day-to-day infection prevention efforts as well as in disaster preparedness. SBT is underutilized in infection prevention but can serve as a crucial educational tool.
Background: Whereas the beneficial effect of antiplatelet therapy for recurrent stroke prevention is well-established, uncertainties remain regarding the optimal anti-thrombotic regimen for acutely symptomatic carotid stenosis (“hot carotid”), particularly as patients await revascularization. We sought to explore the approaches of stroke physicians to peri-procedural anti-thrombotic management of patients with “hot carotids”. Methods: We conducted semi-structured interviews regarding “hot carotid” management with purposive sampling of 20 stroke physicians from 14 centres in North America, Europe, Asia, and Australia. We identified key themes using conventional qualitative content analysis. Results: Important themes revealed from our discussion included limitations of existing clinical trial evidence, competing surgeon versus neurologist/internist preferences, and single vs dual antiplatelet therapy (DAPT) while awaiting revascularization. Areas of uncertainty included the management of stroke while on aspirin, implications of non-stenotic features of carotid disease (intraluminal thrombus, plaque morphology), the role of newer anti-platelet agents or anticoagulants, platelet aggregation testing, and how soon to start DAPT. Conclusions: Our qualitative analysis revealed themes that were important to stakeholders in stroke care. Teams designing international trials will have to accommodate identified variations in anti-thrombotic practice patterns and take into consideration areas of uncertainty, such as newer anti-thrombotic agents, and the implication of non-stenotic features of carotid disease.
Background: Evidence informing the choice between endarterectomy and stenting for acutely symptomatic carotid stenosis (“hot carotid”) is dated, and uncertainties remain regarding the optimal imaging modality. We sought to explore the thoughts of stroke physicians regarding the perioperative management of patients with acute symptomatic carotid stenosis. Methods: We conducted semi-structured interviews regarding “hot carotid” management with purposive sampling of 20 stroke physicians from 14 centres in North America, Europe, Asia, and Australia. We identified key themes using conventional qualitative content analysis. Results: Timely imaging availability, breadth of information gained, and surgeon/interventionalist preference emerged as important themes informing the choice of imaging modality. Multidisciplinary decision making, operating room/angiography suite availability, and implications of patient age and infarct size were important themes related to the choice of revascularization. Areas of uncertainty included utility of carotid plaque imaging, timing of revascularization, and the role of intervention with borderline stenosis or intraluminal thrombus. Conclusions: Our qualitative analysis revealed themes that were important to stroke experts. Teams designing international trials will have to accommodate identified variations in practice patterns and take into consideration areas of uncertainty, such as timing of revascularization, imaging of carotid plaque and non-stenotic features of carotid disease (intraluminal thrombus, plaque morphology).
Problematic anger is frequently reported by soldiers who have deployed to combat zones. However, evidence is lacking with respect to how anger changes over a deployment cycle, and which factors prospectively influence change in anger among combat-deployed soldiers.
Methods
Reports of problematic anger were obtained from 7298 US Army soldiers who deployed to Afghanistan in 2012. A series of mixed-effects growth models estimated linear trajectories of anger over a period of 1–2 months before deployment to 9 months post-deployment, and evaluated the effects of pre-deployment factors (prior deployments and perceived resilience) on average levels and growth of problematic anger.
Results
A model with random intercepts and slopes provided the best fit, indicating heterogeneity in soldiers' levels and trajectories of anger. First-time deployers reported the lowest anger overall, but the most growth in anger over time. Soldiers with multiple prior deployments displayed the highest anger overall, which remained relatively stable over time. Higher pre-deployment resilience was associated with lower reports of anger, but its protective effect diminished over time. First- and second-time deployers reporting low resilience displayed different anger trajectories (stable v. decreasing, respectively).
Conclusions
Change in anger from pre- to post-deployment varies based on pre-deployment factors. The observed differences in anger trajectories suggest that efforts to detect and reduce problematic anger should be tailored for first-time v. repeat deployers. Ongoing screening is needed even for soldiers reporting high resilience before deployment, as the protective effect of pre-deployment resilience on anger erodes over time.
Retrospective self-report is typically used for diagnosing previous pediatric traumatic brain injury (TBI). A new semi-structured interview instrument (New Mexico Assessment of Pediatric TBI; NewMAP TBI) investigated test–retest reliability for TBI characteristics in both the TBI that qualified for study inclusion and for lifetime history of TBI.
Method:
One-hundred and eight-four mTBI (aged 8–18), 156 matched healthy controls (HC), and their parents completed the NewMAP TBI within 11 days (subacute; SA) and 4 months (early chronic; EC) of injury, with a subset returning at 1 year (late chronic; LC).
Results:
The test–retest reliability of common TBI characteristics [loss of consciousness (LOC), post-traumatic amnesia (PTA), retrograde amnesia, confusion/disorientation] and post-concussion symptoms (PCS) were examined across study visits. Aside from PTA, binary reporting (present/absent) for all TBI characteristics exhibited acceptable (≥0.60) test–retest reliability for both Qualifying and Remote TBIs across all three visits. In contrast, reliability for continuous data (exact duration) was generally unacceptable, with LOC and PCS meeting acceptable criteria at only half of the assessments. Transforming continuous self-report ratings into discrete categories based on injury severity resulted in acceptable reliability. Reliability was not strongly affected by the parent completing the NewMAP TBI.
Conclusions:
Categorical reporting of TBI characteristics in children and adolescents can aid clinicians in retrospectively obtaining reliable estimates of TBI severity up to a year post-injury. However, test–retest reliability is strongly impacted by the initial data distribution, selected statistical methods, and potentially by patient difficulty in distinguishing among conceptually similar medical concepts (i.e., PTA vs. confusion).
Definition of disorder subtypes may facilitate precision treatment for posttraumatic stress disorder (PTSD). We aimed to identify PTSD subtypes and evaluate their associations with genetic risk factors, types of stress exposures, comorbidity, and course of PTSD.
Methods
Data came from a prospective study of three U.S. Army Brigade Combat Teams that deployed to Afghanistan in 2012. Soldiers with probable PTSD (PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders-Fifth Edition ≥31) at three months postdeployment comprised the sample (N = 423) for latent profile analysis using Gaussian mixture modeling and PTSD symptom ratings as indicators. PTSD profiles were compared on polygenic risk scores (derived from external genomewide association study summary statistics), experiences during deployment, comorbidity at three months postdeployment, and persistence of PTSD at nine months postdeployment.
Results
Latent profile analysis revealed profiles characterized by prominent intrusions, avoidance, and hyperarousal (threat-reactivity profile; n = 129), anhedonia and negative affect (dysphoric profile; n = 195), and high levels of all PTSD symptoms (high-symptom profile; n = 99). The threat-reactivity profile had the most combat exposure and the least comorbidity. The dysphoric profile had the highest polygenic risk for major depression, and more personal life stress and co-occurring major depression than the threat-reactivity profile. The high-symptom profile had the highest rates of concurrent mental disorders and persistence of PTSD.
Conclusions
Genetic and trauma-related factors likely contribute to PTSD heterogeneity, which can be parsed into subtypes that differ in symptom expression, comorbidity, and course. Future studies should evaluate whether PTSD typology modifies treatment response and should clarify distinctions between the dysphoric profile and depressive disorders.
Ecosystem modeling, a pillar of the systems ecology paradigm (SEP), addresses questions such as, how much carbon and nitrogen are cycled within ecological sites, landscapes, or indeed the earth system? Or how are human activities modifying these flows? Modeling, when coupled with field and laboratory studies, represents the essence of the SEP in that they embody accumulated knowledge and generate hypotheses to test understanding of ecosystem processes and behavior. Initially, ecosystem models were primarily used to improve our understanding about how biophysical aspects of ecosystems operate. However, current ecosystem models are widely used to make accurate predictions about how large-scale phenomena such as climate change and management practices impact ecosystem dynamics and assess potential effects of these changes on economic activity and policy making. In sum, ecosystem models embedded in the SEP remain our best mechanism to integrate diverse types of knowledge regarding how the earth system functions and to make quantitative predictions that can be confronted with observations of reality. Modeling efforts discussed are the Century ecosystem model, DayCent ecosystem model, Grassland Ecosystem Model ELM, food web models, Savanna model, agent-based and coupled systems modeling, and Bayesian modeling.
Unit cohesion may protect service member mental health by mitigating effects of combat exposure; however, questions remain about the origins of potential stress-buffering effects. We examined buffering effects associated with two forms of unit cohesion (peer-oriented horizontal cohesion and subordinate-leader vertical cohesion) defined as either individual-level or aggregated unit-level variables.
Methods
Longitudinal survey data from US Army soldiers who deployed to Afghanistan in 2012 were analyzed using mixed-effects regression. Models evaluated individual- and unit-level interaction effects of combat exposure and cohesion during deployment on symptoms of post-traumatic stress disorder (PTSD), depression, and suicidal ideation reported at 3 months post-deployment (model n's = 6684 to 6826). Given the small effective sample size (k = 89), the significance of unit-level interactions was evaluated at a 90% confidence level.
Results
At the individual-level, buffering effects of horizontal cohesion were found for PTSD symptoms [B = −0.11, 95% CI (−0.18 to −0.04), p < 0.01] and depressive symptoms [B = −0.06, 95% CI (−0.10 to −0.01), p < 0.05]; while a buffering effect of vertical cohesion was observed for PTSD symptoms only [B = −0.03, 95% CI (−0.06 to −0.0001), p < 0.05]. At the unit-level, buffering effects of horizontal (but not vertical) cohesion were observed for PTSD symptoms [B = −0.91, 90% CI (−1.70 to −0.11), p = 0.06], depressive symptoms [B = −0.83, 90% CI (−1.24 to −0.41), p < 0.01], and suicidal ideation [B = −0.32, 90% CI (−0.62 to −0.01), p = 0.08].
Conclusions
Policies and interventions that enhance horizontal cohesion may protect combat-exposed units against post-deployment mental health problems. Efforts to support individual soldiers who report low levels of horizontal or vertical cohesion may also yield mental health benefits.
In product design engineering (PDE), ideation involves the generation of technical behaviours and physical structures to address specific functional requirements. This differs from generic creative ideation tasks, which emphasise functional and technical considerations less. To advance knowledge about the neural basis of PDE ideation, we present the first fMRI study on professional product design engineers practising in industry. We aimed to explore brain activation during ideation, and compare activation in open-ended and constrained tasks. Imagery manipulation tasks were contrasted with ideation tasks in a sample of 29 PDE professionals. The key findings were: (1) PDE ideation is associated with greater activity in left cingulate gyrus; (2) there were no significant differences between open-ended and constrained tasks; and (3) a preliminary association with activity in the right superior temporal gyrus was also observed. The results are consistent with existing fMRI work on generic creative ideation, suggesting that PDE ideation may share a number of similarities at the neural level. Future work includes: functional connectivity analysis of open-ended and constrained ideation to further investigate potential differences; investigating the effects of aspects of design expertise/training on processing; and the use of novelty measures directly linked to the designer’s internal processing in fMRI analysis.
Frascati international research criteria for HIV-associated neurocognitive disorders (HAND) are controversial; some investigators have argued that Frascati criteria are too liberal, resulting in a high false positive rate. Meyer et al. recommended more conservative revisions to HAND criteria, including exploring other commonly used methodologies for neurocognitive impairment (NCI) in HIV including the global deficit score (GDS). This study compares NCI classifications by Frascati, Meyer, and GDS methods, in relation to neuroimaging markers of brain integrity in HIV.
Method:
Two hundred forty-one people living with HIV (PLWH) without current substance use disorder or severe (confounding) comorbid conditions underwent comprehensive neurocognitive testing and brain structural magnetic resonance imaging and magnetic resonance spectroscopy. Participants were classified using Frascati criteria versus Meyer criteria: concordant unimpaired [Frascati(Un)/Meyer(Un)], concordant impaired [Frascati(Imp)/Meyer(Imp)], or discordant [Frascati(Imp)/Meyer(Un)] which were impaired via Frascati criteria but unimpaired via Meyer criteria. To investigate the GDS versus Meyer criteria, the same groupings were utilized using GDS criteria instead of Frascati criteria.
Results:
When examining Frascati versus Meyer criteria, discordant Frascati(Imp)/Meyer(Un) individuals had less cortical gray matter, greater sulcal cerebrospinal fluid volume, and greater evidence of neuroinflammation (i.e., choline) than concordant Frascati(Un)/Meyer(Un) individuals. GDS versus Meyer comparisons indicated that discordant GDS(Imp)/Meyer(Un) individuals had less cortical gray matter and lower levels of energy metabolism (i.e., creatine) than concordant GDS(Un)/Meyer(Un) individuals. In both sets of analyses, the discordant group did not differ from the concordant impaired group on any neuroimaging measure.
Conclusions:
The Meyer criteria failed to capture a substantial portion of PLWH with brain abnormalities. These findings support continued use of Frascati or GDS criteria to detect HIV-associated CNS dysfunction.