Effects of HIV and early life stress on amygdala morphometry and neurocognitive function

Neigh G, Jovanovic T, Michopoulos V. HIV Interacts with Posttraumatic Stress Disorder to Impact Fear Psychophysiology in Trauma-Exposed Black Women

Background

The prevalence of posttraumatic stress disorder (PTSD) among people living with HIV (PLWH) is higher than in the general population and can impact health behaviors. The influence of HIV on PTSD psychophysiology requires further investigation due to implications for the treatment of PTSD in PLWH.

Objective

Utilizing fear-potentiated startle (FPS), we aimed to interrogate the influence of PTSD and HIV on fear responses.

Materials and Methods

Women (18-65 years of age) recruited from the Women's Interagency HIV Study in Atlanta, GA (n = 70, 26 without HIV and 44 with HIV), provided informed consent and completed a semistructured interview to assess trauma exposure and PTSD symptom severity. Participants also underwent an FPS paradigm to assess fear acquisition and extinction: Psychophysiological indices that measure how individuals learn new fear and then subsequently attempt to suppress this fear.

Results

Women with PTSD, who did not have HIV, exhibited a greater startle response compared to women without PTSD or HIV during late acquisition to both the danger cue, reinforced conditioned stimulus (CS+, p = 0.013)), and the safety cue, non-reinforced conditioned stimulus (CS-, p = 0.046)), whereas women living with HIV (WLH) and PTSD demonstrated blunted fear responses compared to women with PTSD only. During extinction, WLH comorbid with PTSD exhibited an increased fear response during the extinction period in comparison to all other groups (p = 0.023). Women without PTSD demonstrated a reduction in the fear response during extinction regardless of HIV status.

Conclusion

Our findings indicate that HIV further modifies fear psychophysiology in WLH with comorbid PTSD, highlighting the importance of considering HIV status in conjunction with PTSD treatment.

Modularity-Constrained Dynamic Representation Learning for Interpretable Brain Disorder Analysis with Functional MRI

Resting-state functional MRI (rs-fMRI) is increasingly used to detect altered functional connectivity patterns caused by brain disorders, thereby facilitating objective quantification of brain pathology. Existing studies typically extract fMRI features using various machine/deep learning methods, but the generated imaging biomarkers are often challenging to interpret. Besides, the brain operates as a modular system with many cognitive/topological modules, where each module contains subsets of densely inter-connected regions-of-interest (ROIs) that are sparsely connected to ROIs in other modules. However, current methods cannot effectively characterize brain modularity. This paper proposes a modularity-constrained dynamic representation learning (MDRL) framework for interpretable brain disorder analysis with rs-fMRI. The MDRL consists of 3 parts: (1) dynamic graph construction, (2) modularity-constrained spatiotemporal graph neural network (MSGNN) for dynamic feature learning, and (3) prediction and biomarker detection. In particular, the MSGNN is designed to learn spatiotemporal dynamic representations of fMRI, constrained by 3 functional modules (i.e., central executive network, salience network, and default mode network). To enhance discriminative ability of learned features, we encourage the MSGNN to reconstruct network topology of input graphs. Experimental results on two public and one private datasets with a total of 1,155 subjects validate that our MDRL outperforms several state-of-the-art methods in fMRI-based brain disorder analysis. The detected fMRI biomarkers have good explainability and can be potentially used to improve clinical diagnosis.

Synergistic effects of high early-life stress exposure and HIV infection on reaction time variability

Addressing comorbidities contributing to cognitive impairment in people living with HIV (PLWH) remains imperative. Prior studies utilizing reaction time intra-individual variability (RT-IIV), a robust behavioral marker of cognitive dysfunction, demonstrate increased cognitive impairment in adults living with HIV who have high early life stress (ELS) exposure relative to those with low-ELS exposure. Yet, it is unknown whether RT-IIV elevations are due to high-ELS alone or both HIV-status and high-ELS. In the current study, we explore the potential additive effects of HIV and high-ELS exposure on RT-IIV to better characterize the independent and combined effects of these factors on RT-IIV among PLWH. We assessed 59 PLWH and 69 HIV-negative healthy control (HC) participants with either low or high ELS on RT-IIV during a working memory task (1-back). We observed a significant interaction between HIV status and ELS exposure on RT-IIV, PLWH who had experienced high ELS demonstrating RT-IIV elevations relative to all other groups. In addition, RT-IIV was significantly associated with ELS exposure in PLWH, but not in the HC group. We also observed associations between RT-IIV and measures of HIV-disease severity (plasma HIV viral load, nadir CD4) among PLWH. Taken as a whole, these findings provide novel evidence of the combined effects of HIV and high-ELS exposure on RT-IIV, and thus suggest HIV-related and ELS-related neural abnormalities may act in an additive or synergistic manner to affect cognition. Such data warrant further investigation into the neurobiological mechanisms associated with HIV and high-ELS exposure that contribute to increased neurocognitive dysfunction among PLWH.

Effects of clinical, comorbid, and social determinants of health on brain ageing in people with and without HIV: a retrospective case-control study

BACKGROUND

Neuroimaging reveals structural brain changes linked with HIV infection and related neurocognitive disorders; however, group-level comparisons between people with HIV and people without HIV do not account for within-group heterogeneity. The aim of this study was to quantify the effects of comorbidities such as cardiovascular disease and adverse social determinants of health on brain ageing in people with HIV and people without HIV.

METHODS

In this retrospective case-control study, people with HIV from Washington University in St Louis, MO, USA, and people without HIV identified through community organisations or the Research Participant Registry were clinically characterised and underwent 3-Tesla T1-weighted MRI between Dec 3, 2008, and Oct 4, 2022. Exclusion criteria were established by a combination of self-reports and medical records. DeepBrainNet, a publicly available machine learning algorithm, was applied to estimate brain-predicted age from MRI for people with HIV and people without HIV. The brain-age gap, defined as the difference between brain-predicted age and true chronological age, was modelled as a function of clinical, comorbid, and social factors by use of linear regression. Variables were first examined singly for associations with brain-age gap, then combined into multivariate models with best-subsets variable selection.

FINDINGS

In people with HIV (mean age 44·8 years [SD 15·5]; 78% [296 of 379] male; 69% [260] Black; 78% [295] undetectable viral load), brain-age gap was associated with Framingham cardiovascular risk score (p=0·0034), detectable viral load (>50 copies per mL; p=0·0023), and hepatitis C co-infection (p=0·0065). After variable selection, the final model for people with HIV retained Framingham score, hepatitis C, and added unemployment (p=0·0015). Educational achievement assayed by reading proficiency was linked with reduced brain-age gap (p=0·016) for people without HIV but not for people with HIV, indicating a potential resilience factor. When people with HIV and people without HIV were modelled jointly, selection resulted in a model containing cardiovascular risk (p=0·0039), hepatitis C (p=0·037), Area Deprivation Index (p=0·033), and unemployment (p=0·00010). Male sex (p=0·078) and alcohol use history (p=0·090) were also included in the model but were not individually significant.

INTERPRETATION

Our findings indicate that comorbid and social determinants of health are associated with brain ageing in people with HIV, alongside traditional HIV metrics such as viral load and CD4 cell count, suggesting the need for a broadened clinical perspective on healthy ageing with HIV, with additional focus on comorbidities, lifestyle changes, and social factors.

FUNDING

National Institute of Mental Health, National Institute of Nursing Research, and National Institute of Drug Abuse.

The Evolution of Assessing Central Nervous System Complications in Human Immunodeficiency Virus: Where Do We Go From Here?

In this fifth decade of the human immunodeficiency virus (HIV) epidemic, central nervous system (CNS) complications including cognitive impairment and mental health remain a burden for people with HIV (PWH) on antiretroviral therapy. Despite the persistence of these complications, which often co-occur, the underlying pathophysiology remains elusive and consequently treatments remain limited. To continue to grow our understanding of the underlying mechanisms of CNS complications among PWH, there is a need to reexamine our current approaches, which are now more than 2 decades old. At the 2021 National Institutes of Health-sponsored meeting on Biotypes of CNS Complications in PWH, the Neurobehavioral Working Group addressed the following: (1) challenges inherent to determining CNS complications; (2) heterogeneity in CNS complications; and (3) problems and solutions for examining integrated biotypes. The review below provides a summary of the main points presented and discussed by the Neurobehavioral Working Group at the meeting.

Effects of Early-Life Adversities on Neuropsychiatric and Executive Functions in HIV-Positive Adults

OBJECTIVE

Adverse childhood experiences (ACEs) contribute to elevations in neuropsychiatric and neurocognitive symptoms in HIV+ adults. Emerging data suggest that exposures to threat-related and deprivation-related ACEs may have differential impacts on function, with threat exposure contributing to neuropsychiatric symptoms, and deprivation contributing to executive dysfunction. Yet, it remains unclear how specific types of ACEs impact neuropsychiatric and neurocognitive symptoms in HIV+ adults. Hence, the current study examined whether these two dimensions of adversity contribute differentially to neuropsychiatric symptoms and executive dysfunction in HIV+ adults.

METHODS

We included a sample of demographically matched HIV+ (N = 72) and HIV-negative (N = 85) adults. Standardized self-report measures assessed threat-related (interpersonal violence) and deprivation-related (poverty/neglect) ACEs, as well as neuropsychiatric symptoms (depression, anxiety, apathy). A brief battery of neuropsychological tests assessed executive functions.

RESULTS

Compared to HIV-negative participants, HIV+ participants reported significantly higher rates of threat exposure (51% vs. 67%, p = .04), while rates of deprivation did not differ significantly (8% vs. 13%, p = .38). In the HIV+ sample, threat exposure was associated with neuropsychiatric symptoms (p < .01) but not executive dysfunction (p = .75). By contrast, deprivation was associated with executive dysfunction, at a trend level (p = .09), but not with neuropsychiatric symptoms (p = .70).

CONCLUSIONS

Our data suggest that, relative to HIV-negative samples, HIV+ samples experience higher rates of threat-related ACEs, which contribute to neuropsychiatric symptom elevations. Moreover, our preliminary findings suggest that different types of ACEs could be associated with different profiles of neuropsychiatric and neurocognitive difficulty in HIV+ adults, highlighting the importance of considering dimensions of adversity in future studies.

Alexithymia Among People Living with HIV: A Scoping Review

The present scoping review aimed to identify studies that investigated alexithymia, defined as a difficulty in identifying and describing one's own emotions, in people living with HIV (PLWH).A literature search, in line with the guidelines of PRISMA-ScR, was conducted in the following bibliographic databases: PubMed, PsycINFO, and Web of Science. The databases were queried using the following strings (using Boolean operators): ("alexithymia" OR "alexithymic") AND ("HIV" OR "Human Immunodeficiency Virus"). In line with the eligibility criteria, fourteen articles were found.Ten studies showed the involvement of alexithymia in disease severity (e.g., viral load levels), and adherence to antiretroviral therapy. Three studies revealed an association between alexithymia and cardiovascular disease, and three studies highlighted the implication of alexithymia in cognitive impairment.This review revealed the complex role of alexithymia in HIV disease. A careful clinical assessment of the emotional regulation process of PLWH can provide useful prognostic information.

Prefrontal Cortex Volume Mediates the Relationship Between Lifetime Chronic Stressor Exposure and Cognition in People Living With and Without HIV

OBJECTIVE

Despite considerable research documenting how stress affects brain and neurobehavioral outcomes, few studies have assessed stressor exposure occurring over the entire life span, and no studies have investigated these associations in people living with HIV (PLWH), despite the high stress and disease burden experienced by this population. To address this issue, we examined how cumulative lifetime chronic stressor exposure related to cognition and brain integrity (i.e., gray matter volume) in White and African American PLWH and HIV-uninfected (HIV-) adults.

METHOD

Participants were 91 community-dwelling adults (47.3% PLWH) who completed a comprehensive interview assessing lifetime stressor exposure using the Stress and Adversity Inventory and underwent neuropsychological testing and structural magnetic resonance imaging. Regional brain volumes were derived from T1-weighted images processed through Freesurfer.

RESULTS

As hypothesized, greater lifetime chronic stressor exposure was related to worse global cognition ( b = -0.06, standard error [SE] = 0.03, p = .032), processing speed ( b = -0.04, SE = 0.14, p = .041), and executive functioning ( b = -0.06, SE = 0.02, p = .02), and smaller prefrontal cortex (PFC) volume ( b = -16.20, SE = 5.78, p = .007). HIV status did not moderate any of these associations. Moreover, results from mediation analyses demonstrated that the relationship between lifetime chronic stressor exposure and processing speed was fully mediated by PFC volume.

CONCLUSIONS

These results highlight the critical role of the PFC in the maintenance of processing speed abilities and its vulnerability to cumulative stressor exposure. Specifically, the negative impact of lifetime chronic stressor exposure on cognition-particularly functions reliant on frontal lobe integrity-may be partly driven by smaller volumes in the PFC.

Neurodegeneration Within the Amygdala Is Differentially Induced by Opioid and HIV-1 Tat Exposure

Opioid use disorder (OUD) is a critical problem that contributes to the spread of HIV and may intrinsically worsen neuroHIV. Despite the advent of combined antiretroviral therapies (cART), about half of persons infected with HIV (PWH) experience cognitive and emotional deficits that can be exacerbated by opioid abuse. HIV-1 Tat is expressed in the central nervous system (CNS) of PWH on cART and is thought to contribute to neuroHIV. The amygdala regulates emotion and memories associated with fear and stress and is important in addiction behavior. Notwithstanding its importance in emotional saliency, the effects of HIV and opioids in the amygdala are underexplored. To assess Tat- and morphine-induced neuropathology within the amygdala, male Tat transgenic mice were exposed to Tat for 8 weeks and administered saline and/or escalating doses of morphine twice daily (s.c.) during the last 2 weeks of Tat exposure. Eight weeks of Tat exposure decreased the acoustic startle response and the dendritic spine density in the basolateral amygdala, but not the central nucleus of the amygdala. In contrast, repeated exposure to morphine alone, but not Tat, increased the acoustic startle response and whole amygdalar levels of amyloid-β (Aβ) monomers and oligomers and tau phosphorylation at Ser396, but not neurofilament light chain levels. Co-exposure to Tat and morphine decreased habituation and prepulse inhibition to the acoustic startle response and potentiated the morphine-induced increase in Aβ monomers. Together, our findings indicate that sustained Tat and morphine exposure differentially promote synaptodendritic degeneration within the amygdala and alter sensorimotor processing.

HIV-Associated Structural and Functional Brain Alterations in Homosexual Males

Purpose:

Neuroimaging elucidations have shown structural and functional brain alterations in HIV-infected (HIV+) individuals when compared to HIV-negative (HIV–) controls. However, HIV− groups used in previous studies were not specifically considered for sexual orientation, which also affects the brain structures and functions. The current study aimed to characterize the brain alterations associated with HIV infection while controlling for sexual orientation.

Methods:

Forty-three HIV+ and 40 HIV– homosexual men (HoM) were recruited and underwent resting-state MRI scanning. Group differences in gray matter volume (GMV) were assessed using a voxel-based morphometry analysis. Brain regions with the altered GMV in the HIV+ HoM group were then taken as regions of interest in a seed-based analysis to identify altered functional connectivity. Furthermore, the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity values were compared between the two groups to evaluate the HIV-associated functional abnormalities in local brain regions.

Results:

HIV+ HoM showed significantly increased GMV in the bilateral parahippocampal gyrus and amygdala, and decreased GMV in the right inferior cerebellum, compared with the HIV– HoM. The brain regions with increased GMV were hyper-connected with the left superior cerebellum, right lingual gyrus, and left precuneus in the HIV+ HoM. Moreover, the ALFF values of the right fusiform gyrus, and left parahippocampal gyrus were increased in the HIV+ HoM. The regional homogeneity values of the right anterior cingulate and paracingulate gyri, and left superior cerebellum were decreased in the HIV+ HoM.

Conclusion:

When the study population was restricted to HoM, HIV+ individuals exhibited structural alterations in the limbic system and cerebellum, and functional abnormalities in the limbic, cerebellum, and visual network. These findings complement the existing knowledge on the HIV-associated neurocognitive impairment from the previous neuroimaging studies by controlling for the potential confounding factor, sexual orientation. Future studies on brain alternations with the exclusion of related factors like sexual orientation are needed to understand the impact of HIV infection on neurocognitive function more accurately.

Mini-review: Elucidating the psychological, physical, and sex-based interactions between HIV infection and stress

Stress is generally classified as any mental or emotional strain resulting from difficult circumstances, and can manifest in the form of depression, anxiety, post-traumatic stress disorder (PTSD), or other neurocognitive disorders. Neurocognitive disorders such as depression, anxiety, and PTSD are large contributors to disability worldwide, and continue to affect individuals and communities. Although these disorders affect men and women, women are disproportionately represented among those diagnosed with affective disorders, a result of both societal gender roles and physical differences. Furthermore, the incidence of these neurocognitive disorders is augmented among People Living with HIV (PLWH); the physical ramifications of stress increase the likelihood of HIV acquisition, pathogenesis, and treatment, as both stress and HIV infection are characterized by chronic inflammation, which creates a more opportunistic environment for HIV. Although the stress response is facilitated by the autonomic nervous system (ANS) and the hypothalamic pituitary adrenal (HPA) axis, when the response involves a psychological component, additional brain regions are engaged. The impact of chronic stress exposure and the origin of individual variation in stress responses and resilience are at least in part attributable to regions outside the primary stress circuity, including the amygdala, prefrontal cortex, and hippocampus. This review aims to elucidate the relationship between stress and HIV, how these interact with sex, and to understand the physical ramifications of these interactions.

Effect of HIV and Interpersonal Trauma on Cortical Thickness, Cognition, and Daily Functioning

BACKGROUND

Interpersonal trauma (IPT) is highly prevalent among HIV-positive (HIV+) individuals, but its relationship with brain morphology and function is poorly understood.

SETTING

This cross-sectional analysis evaluated the associations of IPT with cognitive task performance, daily functioning, magnetic resonance imaging (MRI) brain cortical thickness, and bilateral volumes of 4 selected basal ganglia regions in a US-based cohort of aviremic HIV+ individuals, with (HIV+ IPT+) and without IPT exposure (HIV+ IPT-), and sociodemographically matched HIV-negative controls with (HIV- IPT+) and without IPT exposure (HIV- IPT-).

METHODS

Enrollees completed brain MRI scans, a semistructured psychiatric interview, a neurocognitive battery, and 3 measures of daily functioning. Demographic and clinical characteristics of the 4 groups were described, and pairwise between-group comparisons performed using χ tests, analysis of variance, or t-tests. Linear or Poisson regressions evaluated relationships between group status and the outcomes of interest, in 6 pairwise comparisons, using Bonferroni correction for statistical significance.

RESULTS

Among 187 participants (mean age 50.0 years, 63% male, 64% non-white), 102 were HIV+ IPT+, 35 were HIV+ IPT-, 26 were HIV- IPT-, and 24 were HIV- IPT+. Compared with the remaining 3 groups, the HIV+ IPT+ group had more activities of daily living declines, higher number of impaired Patient's Assessment of Own Functioning Inventory scores, and lower cortical thickness in multiple cerebral regions. Attention/working memory test performances were significantly better in HIV- IPT- compared with the HIV+ IPT+ and HIV+ IPT- groups. Basal ganglia MRI volumes were not significantly different in any between-group comparisons.

CONCLUSION

IPT exposure and HIV infection have a synergistic effect on daily functioning and cortical thickness in aviremic HIV+ individuals.

Neurobehavioral outcomes in young adults with perinatally acquired HIV

BACKGROUND

With combination antiretroviral therapy (cART), infants with perinatally acquired HIV (pHIV) are living into adolescence and adulthood. Worldwide, many have not received cART in the first years of life, and challenges of adolescence complicate transition to adulthood. Neurobehavioral outcomes in pHIV young adults (pHIVAd) are infrequently reported.

OBJECTIVES

To examine neurobehavioral characteristics of pHIVAd ages 21-30 years, and to compare them with age-matched young adults infected in the second or third decade of life (HIVagematch), and older adults with similar duration HIV disease (HIVOA).

METHODS

A comprehensive neuropsychological test battery and questionnaires to determine cognitive function and mood, and reviews of neuromedical and behavioral records were undertaken in three groups of 13 individuals each. Descriptive analysis and bivariate techniques were used for comparisons.

RESULTS

Rates of cognitive impairment were highest in pHIVAd (85%) compared with HIVagematch (38%) and HIVOA (62%). pHIVAd had the worst scores in global cognition, speed of information processing, working memory, and verbal fluency (0.5--1.0 SD below other groups). There was a trend for higher rates of psychiatric dysfunction (predominantly mood disorders) in pHIVAd (85%) compared with HIV-agematch (46%) and HIVOA (54%). Only four pHIVAd reported employment or enrollment in school. Four had autoimmune disorders.

CONCLUSION

These pHIVAd displayed high rates of cognitive, psychiatric, and autoimmune dysfunction, greater than age-matched or HIV duration-matched comparators. Although this small study is largely descriptive in nature, it suggests that a lack of cART in early life may result in long-term neurobehavioral and immune abnormalities manifesting into adulthood.

The Association Between Olfactory Function and Cognition in Aging African American and Caucasian Men With HIV: A Pilot Study

Older adults and people living with HIV have been shown to experience disproportionately more olfactory dysfunction. Some neurological studies suggest that olfactory dysfunction may be a precursor to cognitive dysfunction. The purpose of our study was to determine whether olfactory dysfunction was predictive of cognition. In our cross-sectional study, 51 African American and Caucasian men living with HIV (ages ≥ 40 years) were administered a cognitive performance battery and two objective olfactory measures (the University of Pennsylvania Smell Identification Test and the Smell Threshold Test). The strongest cognitive associations to the University of Pennsylvania Smell Identification Test performance were found in the Hopkins Verbal Learning Test, a measure of verbal learning and verbal memory. These findings were consistent with previous research, demonstrating a relationship between decreased olfactory function and poorer cognitive performance. An important clinical implication from these results is the potential use of olfactory dysfunction as a prodromal biomarker for HIV-associated neurocognitive disorder.

The relationship between potentially traumatic or stressful events, HIV infection and neurocognitive impairment (NCI): a systematic review of observational epidemiological studies

BACKGROUND

HIV/AIDS and potentially traumatic events (PTEs) or stressful life events (SLEs) and/or PTSD are independently associated with neurocognitive impairment (NCI). Literature suggests that HIV and PTE/SLE exposure independently and consistently affect various domains of cognition including language ability, working memory and psychomotor speed. There are limited data on the interaction between HIV infection and PTEs and their combined effect on NCI.

OBJECTIVE

In this systematic review, we synthesise evidence for the combined effect of HIV infection and PTEs and SLEs and/or post-traumatic stress disorder (PTSD) on NCI of people living with HIV/AIDS (PLWHA) from high-, middle- and low- income countries.

METHOD

Our inclusion criteria were observational epidemiological studies (case-control, cohort and cross-sectional designs) that investigated the interaction of HIV infection, PTEs and SLEs and/or PTSD and specifically their combined effect on NCI in adults. We searched a number of electronic databases including Pubmed/Medline, PsycINFO, Scopus and Global Health using the search terms: cognition, HIV/AIDS, observational studies, trauma and permutations thereof.

RESULTS

Fifteen studies were included in the review, of which the majority were conducted in high-income countries. Ten of the fifteen studies were conducted in the United States of America (USA) and five in South Africa. Seven of these focused on early life stress/childhood trauma. The remaining studies assessed adult-onset PTEs and SLEs only. Eight studies included women only. Overall, the studies suggest that PTE and SLE exposure and/or PTSD are a significant risk factor for NCI in adults living with HIV, with impairments in memory and executive functions being the most likely consequence of PTE and SLE exposure.

CONCLUSION

These findings highlight the need for trauma screening and for the integration of trauma-focused interventions in HIV care to improve outcomes.

Quantifying deep grey matter atrophy using automated segmentation approaches: A systematic review of structural MRI studies

The deep grey matter (DGM) nuclei of the brain play a crucial role in learning, behaviour, cognition, movement and memory. Although automated segmentation strategies can provide insight into the impact of multiple neurological conditions affecting these structures, such as Multiple Sclerosis (MS), Huntington's disease (HD), Alzheimer's disease (AD), Parkinson's disease (PD) and Cerebral Palsy (CP), there are a number of technical challenges limiting an accurate automated segmentation of the DGM. Namely, the insufficient contrast of T1 sequences to completely identify the boundaries of these structures, as well as the presence of iso-intense white matter lesions or extensive tissue loss caused by brain injury. Therefore in this systematic review, 269 eligible studies were analysed and compared to determine the optimal approaches for addressing these technical challenges. The automated approaches used among the reviewed studies fall into three broad categories, atlas-based approaches focusing on the accurate alignment of atlas priors, algorithmic approaches which utilise intensity information to a greater extent, and learning-based approaches that require an annotated training set. Studies that utilise freely available software packages such as FIRST, FreeSurfer and LesionTOADS were also eligible, and their performance compared. Overall, deep learning approaches achieved the best overall performance, however these strategies are currently hampered by the lack of large-scale annotated data. Improving model generalisability to new datasets could be achieved in future studies with data augmentation and transfer learning. Multi-atlas approaches provided the second-best performance overall, and may be utilised to construct a "silver standard" annotated training set for deep learning. To address the technical challenges, providing robustness to injury can be improved by using multiple channels, highly elastic diffeomorphic transformations such as LDDMM, and by following atlas-based approaches with an intensity driven refinement of the segmentation, which has been done with the Expectation Maximisation (EM) and level sets methods. Accounting for potential lesions should be achieved with a separate lesion segmentation approach, as in LesionTOADS. Finally, to address the issue of limited contrast, R2*, T2* and QSM sequences could be used to better highlight the DGM due to its higher iron content. Future studies could look to additionally acquire these sequences by retaining the phase information from standard structural scans, or alternatively acquiring these sequences for only a training set, allowing models to learn the "improved" segmentation from T1-sequences alone.

Effects of trauma, economic hardship, and stress on neurocognition and everyday function in HIV

OBJECTIVE

The causes of neurocognitive and everyday functioning impairment among aging people living with HIV (PLWH) are multifactorial. Exposure to stress and trauma can result in neurocognitive deficits via activation of neurological and other biological mechanisms.

METHOD

PLWH (n = 122) and persons without HIV (n = 95), 35-65 years of age, completed four questionnaires that were used to generate a trauma, economic hardship (food insecurity and low socioeconomic status), and stress composite variable (TES). Participants also completed a comprehensive neuropsychological battery and standardized self-reports of activities of daily living (ADLs). We examined the independent and interactive effects of TES and HIV status on neurocognitive performance and ADL declines.

RESULTS

PLWH had more traumatic events, more food insecurity, lower socioeconomic status, and higher perceived stress compared with HIV- individuals (all ps < .0001). Among PLWH, a higher composite TES score was associated with worse executive functioning (p = .02), worse learning (p = .02), worse working memory (p = .02), and more ADL declines (p < .0001), even after controlling for relevant demographic, psychiatric, substance use, and HIV disease covariates. On their own, individual TES components did not predict these outcomes. Conversely, no significant relationships were observed between TES and cognitive domains nor ADL declines among HIV- individuals.

CONCLUSIONS

A composite score of trauma, economic hardship, and stress was significantly associated with worse neurocognitive performance and functional declines among PLWH. These adverse experiences may contribute to neurocognitive and daily functioning difficulties commonly observed among PLWH. Longitudinal studies are needed to elucidate the relationships between economic/psychosocial adversities and cognitive/functional outcomes over time, and examine potential mediators, such as inflammatory biomarkers. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Incidence and Persistence of Depression Among Women Living with and Without HIV in South Africa: A Longitudinal Study

Depression and trauma are common among women living with HIV. This is the first study to track the longitudinal course of depression and examine the relationship between depression and trauma over time among women in South Africa. HIV-infected and uninfected women (N = 148) were assessed at baseline and one year later. Results of a path analysis show the multi-directional and entwined influence of early life stress, other life-threatening traumas across the lifespan, depression and PTSD over the course of HIV. We also observed higher rates of depressive symptomatology and more persistent cases among infected women compared to uninfected women, as well as a more consistent and enduring relationship between childhood trauma and depression among women living with HIV. The present study is unique in documenting the course of untreated depression and PTSD in women with and without HIV infection with a high prevalence of early childhood trauma.

Resting-state connectivity and spontaneous activity of ventromedial prefrontal cortex predict depressive symptomology and peripheral inflammation in HIV

Depression and chronic inflammation are common in persons infected with the human immunodeficiency virus (HIV+). Although depression and response to inflammatory challenge are shown to reflect activity in common neural networks, little is known regarding sub-clinical presentation in persons chronically infected with HIV. The relationship of resting-state functional connectivity (rsFC) between the subgenual anterior cingulate cortex (sgACC) and bilateral amygdala to Beck Depression Inventory-1 (BDI) scores were compared within a group of 23 HIV+ and 23 HIV-negative comparison adults. An interaction was found wherein lower rsFC between the sgACC and both right and left amygdala was associated with higher BDI scores in HIV+ individuals. Total BDI scores and plasma levels of IL-6, IL-8, TNF-α, and IL-10 made available from 10 of the HIV+ patients were regressed upon an index of spontaneous whole-brain activity at rest; i.e., the amplitude of low-frequency fluctuations (ALFFs). Elevated levels of depression and IL-6 were associated with increased ALFF in a cluster of voxels on the medial portion of the ventral surface of the frontal lobe (Brodmann Area 11). Within this sample of HIV+ individuals lower rsFC of the sgACC with subcortical limbic regions predicts greater burden of depressive symptomology whereas elevated activity in the adjacent BA 11 may reflect sickness, indexed by elevated IL-6, and associated depressive behaviors.

High early life stress and aberrant amygdala activity: risk factors for elevated neuropsychiatric symptoms in HIV+ adults

Relative to HIV-negative adults, HIV+ adults report elevated levels of early life stress (ELS). In non-HIV samples, high ELS has been linked to abnormalities in brain structure and function, as well as increased risk of neuropsychiatric symptoms. Yet, little is known about the neural effects of high ELS, and their relation to elevated neuropsychiatric symptoms, in HIV+ adults. Recent studies have revealed combined effects of HIV and high ELS on amygdala morphometry. Aberrant amygdala activity is prominently implicated in studies of neuropsychiatric symptomology in non-HIV samples. Hence, this preliminary study examined: 1) the combined effects of HIV and high ELS on amygdala activity, and 2) the relation between amygdala activity and neuropsychiatric symptoms in HIV+ adults. We included 28 HIV+ adults and 25 demographically-matched HIV-negative control (HC) adults. ELS exposure was quantified using a retrospective ELS questionnaire, which defined four groups: HIV+ Low-ELS (N = 15); HIV+ High-ELS (N = 13); HC Low-ELS (N = 16); and HC High-ELS (N = 9). Participants completed a battery of neuropsychiatric measures. BOLD fMRI assessed amygdala reactivity during explicit observation of fearful/angry faces. High-ELS participants demonstrated reduced levels of amygdala reactivity relative to Low-ELS participants. HIV+ High-ELS participants reported higher levels of neuropsychiatric symptoms than all other groups. In the HIV+ group, lower amygdala responses were associated with higher neuropsychiatric symptoms, particularly depression, anxiety, and alexithymia. Collectively, these results suggest that high ELS exposure is a significant risk factor for neuropsychiatric symptoms in HIV+ adults. Furthermore, our results implicate ELS-related abnormalities in amygdala activity in the etiology of neuropsychiatric symptoms in HIV+ adults.

Effects of social adversity and HIV on subcortical shape and neurocognitive function

The purpose of the current study was to examine the independent and interactive effects of social adversity (SA) and HIV infection on subcortical shape alterations and cognitive functions. Participants included HIV+ (n = 70) and HIV- (n = 23) individuals who underwent MRI, neurocognitive and clinical assessment, in addition to completing questionnaires from which responses were used to create an SA score. Bilateral amygdalae and hippocampi were extracted from T1-weighted images. Parametric statistical analyses were used to compare the radial distance of the structure surface to a median curve to determine the presence of localized shape differences as a function of HIV, SA and their interaction. Next, multiple regression was used to examine the interactive association between HIV and SA with cognitive performance data. An HIV*SA interactive effect was found on the shape of the right amygdala and left hippocampus. Specifically, HIV-infected participants (but not HIV-uninfected controls) who evidenced higher levels of SA displayed an inward deformation of the surface consistent with reduced volume of these structures. We found interactive effects of HIV and SA on learning/memory performance. These results suggest that HIV+ individuals may be more vulnerable to neurological and cognitive changes in the hippocampus and amygdala as a function of SA than HIV- individuals, and that SA indicators of childhood SES and perceived racial discrimination are important components of adversity that are associated with cognitive performance.

Early Life Stress-Related Elevations in Reaction Time Variability Are Associated with Brain Volume Reductions in HIV+ Adults

There is burgeoning evidence that, among HIV+ adults, exposure to high levels of early life stress (ELS) is associated with increased cognitive impairment as well as brain volume abnormalities and elevated neuropsychiatric symptoms. Currently, we have a limited understanding of the degree to which cognitive difficulties observed in HIV+ High-ELS samples reflect underlying neural abnormalities rather than increases in neuropsychiatric symptoms. Here, we utilized a behavioral marker of cognitive function, reaction time intra-individual variability (RT-IIV), which is sensitive to both brain volume reductions and neuropsychiatric symptoms, to elucidate the unique contributions of brain volume abnormalities and neuropsychiatric symptoms to cognitive difficulties in HIV+ High-ELS adults. We assessed the relation of RT-IIV to neuropsychiatric symptom levels and total gray and white matter volumes in 44 HIV+ adults (26 with high ELS). RT-IIV was examined during a working memory task. Self-report measures assessed current neuropsychiatric symptoms (depression, stress, post-traumatic stress disorder). Magnetic resonance imaging was used to quantify total gray and white matter volumes. Compared to Low-ELS participants, High-ELS participants exhibited elevated RT-IIV, elevated neuropsychiatric symptoms, and reduced gray and white matter volumes. Across the entire sample, RT-IIV was significantly associated with gray and white matter volumes, whereas significant associations with neuropsychiatric symptoms were not observed. In the High-ELS group, despite the presence of elevated neuropsychiatric symptom levels, brain volume reductions explained more than 13% of the variance in RT-IIV, whereas neuropsychiatric symptoms explained less than 1%. Collectively, these data provide evidence that, in HIV+ High-ELS adults, ELS-related cognitive difficulties (as indexed by RT-IIV) exhibit strong associations with global brain volumes, whereas ELS-related elevations in neuropsychiatric symptoms appear to contribute minimally to these cognitive difficulties. Such findings support a growing body of evidence indicating that high ELS exposure is a significant risk factor for neurocognitive dysfunction in HIV+ adults. Further, these data highlight the need to better understand how ELS-related pathophysiological mechanisms contribute to volumetric and other neural abnormalities in HIV+ individuals.

Alterations of brain volumes in women with early life maltreatment and their associations with oxytocin

Early life maltreatment (ELM) is associated with different neurobiological alterations. Lower oxytocin and altered grey matter volumes (GMV) in brain regions associated with the central oxytocin system, such as the hypothalamus, amygdala, and nucleus accumbens, have been reported in women with ELM. However, the association between peripheral oxytocin and brain morphometry in women with ELM has not been studied yet. We therefore collected blood samples from 33 women with and 25 women without ELM, all without current mental disorders to measure and compare oxytocin levels between the two groups. Furthermore, T1-weighted high-resolution structural magnetic resonance brain images of a subsample of these women were collected, analyzed with voxel-based morphometry, compared between the two groups, and correlated with oxytocin levels. There were no differences in oxytocin levels between the groups. However, oxytocin levels were associated with different brain regions in women with ELM compared with control women without ELM: A positive association between GMV in the nucleus accumbens and oxytocin was specific for control women but not for women with ELM. For the hypothalamus, there was a positive association between GMV and oxytocin in control women. However, the same region was negatively associated with oxytocin in women with ELM and it showed larger GMV compared to control women without ELM. For the amygdala, a negative association between GMV and oxytocin was specific for women with ELM. Results are discussed with regard to previous research on endocrine and neurostructural alterations in individuals with ELM.

Experiences of Discrimination Are Associated With Greater Resting Amygdala Activity and Functional Connectivity

BACKGROUND

Social discrimination, a type of psychological stressor, is associated with poorer physical and mental health outcomes, yet we have little understanding of how discrimination affects neural functions in marginalized populations. By contrast, the effects of psychological stress on neural functions are well documented, with evidence of significant effects on the amygdala-a neural region that is central to psychosocial functions. Accordingly, we conducted an examination of the relation between self-reported discrimination exposure and amygdala activity in a diverse sample of adults.

METHODS

Seventy-four adults (43% women; 72% African American; 23% Hispanic; 32% homosexual/bisexual) completed self-report ratings of discrimination exposure. Spontaneous amygdala activity and functional connectivity were assessed during resting-state functional magnetic resonance imaging.

RESULTS

Greater discrimination exposure was associated with higher levels of spontaneous amygdala activity. Increases in discrimination were also associated with stronger functional connectivity between the amygdala and several neural regions (e.g., anterior insula, putamen, caudate, anterior cingulate, medial frontal gyrus), with the most robust effects observed in the thalamus. These effects were independent of several demographic (e.g., race, ethnicity, sex) and psychological (e.g., current stress, depression, anxiety) factors.

CONCLUSIONS

Collectively, our findings provide the first evidence that social discrimination is independently associated with elevations in intrinsic amygdala activity and functional connectivity, thus revealing clear parallels between the neural substrates of discrimination and psychological stressors of other origins. Such results should spur future investigations of amygdala-based networks as potential etiological factors linking discrimination exposure to adverse physical and mental health outcomes.

Childhood maltreatment and HIV-associated neurocognitive disorders share similar pathophysiology: a potential sensitisation mechanism?

HIV-associated neurocognitive disorders (HAND) are increasingly prevalent despite the use of antiretroviral therapies. Previous research suggests that individual host factors play an important role in determining susceptibility to HAND. In this review, we propose that childhood trauma (CT) and HAND share several common aetiological mechanisms, namely hypothalamic-pituitary-adrenal axis dysregulation, neuroinflammation and oxidative stress. These convergent and consequent mechanisms may translate into an increased risk of developing HAND in individuals who have experienced early life stress. We provide an overview of basic and clinical research relating to these pathophysiological mechanisms and suggest that further research examine brain-derived neurotrophic factor and telomere length as common mediating factors and potential therapeutic targets for HAND and CT. Graphical abstract Both childhood trauma and HIV-associated neurocognitive disorders are associated with HPA axis dysregulation, inflammation and oxidative stress.

Effects of Childhood Trauma and Alcoholism History on Neuropsychological Performance in Adults with HIV Infection: An Initial Study

Background

Childhood trauma carries heightened risk for neuropsychological impairment and is a frequent concomitant of HIV infection (H) and alcoholism (Alc). Little is known about compounded effects of childhood trauma and these diseases on cognitive and motor functioning. We queried the relation between childhood trauma history (experiencing at least 1 of 13 specified traumas before age 18) and cognitive and motor performance in HIV infection with and without lifetime alcoholism.

Methods

Relations between childhood trauma history (Tr) and four performance domains (episodic memory, information processing speed, executive function, and fine motor function) were examined via ANCOVAs covarying for age and education in four HIV groups: 21 H+Alc+Tr, 19 H+Alc, 19 H+Tr, and 25 HComp (H comparison group without Tr or Alc).

Results

H+Tr, irrespective of Alc, performed poorly on the episodic memory domain. Specifically, immediate and delayed verbal recall, and immediate visual recall were affected in those with HIV and history of childhood trauma with or without alcoholism history. By contrast, H+Alc+Tr performed faster than H+Alc or H+Tr in information processing speed.

Conclusion

The findings of poorer episodic memory in HIV infection with childhood trauma history corroborates previous reports and now extends findings to H+Alc+Tr trimorbidity. The novel interaction of alcoholism and trauma in HIV infection suggests that information processing speed is slowed with trauma history or alcoholism history alone in HIV but not with HIV+Alc+Tr trimorbidity, possibly reflecting greater impulsivity and hyperarousal in multiply-affected individuals.

Changes in cognitive function in women with HIV infection and early life stress

INTRODUCTION

HIV is frequently associated with deficits in brain function, including memory, psychomotor speed, executive function and attention. Early life stress (ELS) has also been shown to have a direct influence on neurocognitive performance. However, little is known about the combined impact of ELS and HIV on neurocognitive function over time. The aim of the present study was to follow a cohort of affected women, allowing us to assess the effects of HIV and childhood trauma on cognition and the change in cognition over time.

METHOD

A battery of neurocognitive tests was administered to 117 women at baseline and then a year later. The sample included a total of 67 HIV+ and 50 HIV- women, 71 with ELS and 46 without ELS. Controlling for age, education and antiretroviral therapy (ART) at baseline and 12-month follow-up, raw scores were compared across groups using a repeated-measures analysis of covariance.

RESULTS

More women were on ART at follow-up compared to baseline. Results revealed a significant combined HIV and childhood trauma effect over time on the Wisconsin Card Sorting Test (p = .003) and Category Fluency Test (p = .006). A significant individual HIV effect over time was evident on the WAIS-III Digit Symbol Test (p = .03) and the Controlled Oral Word Association Test (p = .003).

CONCLUSION

Findings suggest better performance in abstract reasoning, speed of information processing and verbal fluency over time. While all groups showed improvements that may correspond to practice effects, effects of HIV and childhood trauma remained evident at 12-month follow-up despite greater ART uptake and improved HIV disease status. This is the first study to assess the combined impact of HIV and trauma on neurocognitive function over time in an all-female cohort with more advanced disease.

Expression of gp120 in mice evokes anxiety behavior: Co-occurrence with increased dendritic spines and brain-derived neurotrophic factor in the amygdala

Human immunodeficiency virus type 1 (HIV) infection of the brain produces cognitive and motor disorders. In addition, HIV positive individuals exhibit behavioral alterations, such as apathy, and a decrease in spontaneity or emotional responses, typically seen in anxiety disorders. Anxiety can lead to psychological stress, which has been shown to influence HIV disease progression. These considerations underscore the importance of determining if anxiety in HIV is purely psychosocial, or if by contrast, there are the molecular cascades associated directly with HIV infection that may mediate anxiety. The present study had two goals: (1) to determine if chronic exposure to viral proteins would induce anxiety-like behavior in an animal model and (2) to determine if this exposure results in anatomical abnormalities that could explain increased anxiety. We have used gp120 transgenic mice, which display behavior and molecular deficiencies similar to HIV positive subjects with cognitive and motor impairments. In comparison to wild type mice, 6 months old gp120 transgenic mice demonstrated an anxiety like behavior measured by open field, light/dark transition task, and prepulse inhibition tests. Moreover, gp120 transgenic mice have an increased number of spines in the amygdala, as well as higher levels of brain-derived neurotrophic factor and tissue plasminogen activator when compared to age-matched wild type. Our data support the hypothesis that HIV, through gp120, may cause structural changes in the amygdala that lead to maladaptive responses to anxiety.

Effects of HIV and childhood trauma on brain morphometry and neurocognitive function

A wide spectrum of neurocognitive deficits characterises HIV infection in adults. HIV infection is additionally associated with morphological brain abnormalities affecting neural substrates that subserve neurocognitive function. Early life stress (ELS) also has a direct influence on brain morphology. However, the combined impact of ELS and HIV on brain structure and neurocognitive function has not been examined in an all-female sample with advanced HIV disease. The present study examined the effects of HIV and childhood trauma on brain morphometry and neurocognitive function. Structural data were acquired using a 3T Magnetom MRI scanner, and a battery of neurocognitive tests was administered to 124 women: HIV-positive with ELS (n = 32), HIV-positive without ELS (n = 30), HIV-negative with ELS (n = 31) and HIV-negative without ELS (n = 31). Results revealed significant group volumetric differences for right anterior cingulate cortex (ACC), bilateral hippocampi, corpus callosum, left and right caudate and left and right putamen. Mean regional volumes were lowest in HIV-positive women with ELS compared to all other groups. Although causality cannot be inferred, findings also suggest that alterations in the left frontal lobe, right ACC, left hippocampus, corpus callosum, left and right amygdala and left caudate may be associated with poorer neurocognitive performance in the domains of processing speed, attention/working memory, abstraction/executive functions, motor skills, learning and language/fluency with these effects more pronounced in women living with both HIV and childhood trauma. This study highlights the potential contributory role of childhood trauma to brain alterations and neurocognitive decline in HIV-infected individuals.

Central HIV-1 Tat exposure elevates anxiety and fear conditioned responses of male mice concurrent with altered mu-opioid receptor-mediated G-protein activation and β-arrestin 2 activity in the forebrain

Co-exposure to opiates and HIV/HIV proteins results in enhanced CNS morphological and behavioral deficits in HIV(+) individuals and in animal models. Opiates with abuse liability, such as heroin and morphine, bind preferentially to and have pharmacological actions through μ-opioid-receptors (MORs). The mechanisms underlying opiate-HIV interactions are not understood. Exposure to the HIV-1 transactivator of transcription (Tat) protein causes neurodegenerative outcomes that parallel many aspects of the human disease. We have also observed that in vivo exposure to Tat results in apparent changes in morphine efficacy, and thus have hypothesized that HIV proteins might alter MOR activation. To test our hypothesis, MOR-mediated G-protein activation was determined in neuroAIDS-relevant forebrain regions of transgenic mice with inducible CNS expression of HIV-1 Tat. G-protein activation was assessed by MOR agonist-stimulated [(35)S]guanosine-5'-O-(3-thio)triphosphate ([(35)S]GTPγS) autoradiography in brain sections, and in concentration-effect curves of MOR agonist-stimulated [(35)S]GTPγS binding in membranes isolated from specific brain regions. Comparative studies were done using the MOR-selective agonist DAMGO ([D-Ala(2), N-MePhe(4), Gly-ol]-enkephalin) and a more clinically relevant agonist, morphine. Tat exposure reduced MOR-mediated G-protein activation in an agonist, time, and regionally dependent manner. Levels of the GPCR regulatory protein β-arrestin-2, which is involved in MOR desensitization, were found to be elevated in only one affected brain region, the amygdala; amygdalar β-arrestin-2 also showed a significantly increased association with MOR by co-immunoprecipitation, suggesting decreased availability of MOR. Interestingly, this correlated with changes in anxiety and fear-conditioned extinction, behaviors that have substantial amygdalar input. We propose that HIV-1 Tat alters the intrinsic capacity of MOR to signal in response to agonist binding, possibly via a mechanism involving altered expression and/or function of β-arrestin-2.

The relationship between stress and clinical outcomes for persons living with HIV/AIDS: a systematic review of the global literature

For persons living with HIV/AIDS, the relationship between stress and clinical outcomes has received little attention in current research, yet represents an important area for future research and intervention. Chronic illness has been theorized to place additional demands on a person that may exceed their ability to cope with daily life, leading to long-term stress, which then increases the risk for negative health outcomes in persons already at risk. This paper reviews the existing global literature to answer two main questions: (1) how is stress conceptualized in research with persons living with HIV/AIDS? and (2) what are the current findings linking stress to clinical outcomes? Twenty-three articles are included in the final review. Findings reveal that researchers conceptualize stress in multiple ways for persons living with HIV/AIDS, including depressive symptomology, post-traumatic stress, life events, emotions linked to stress, and biological markers (such as cortisol levels and autonomic nervous system activity). Further, findings related to the link between stress and clinical outcomes are mixed; however, stress was shown to be related to lower CD4 cell counts, higher viral load, and disease progression. Several studies also showed a link between stress and poorer treatment adherence. Implications and directions for future research are discussed, including further thought into how we conceptualize stress for persons living with HIV, future research that is necessary to elucidate current mixed findings on the link between stress and clinical outcomes, and preliminary suggestions for intervention to prevent and alleviate stress in this population.

Human immunodeficiency virus has similar effects on brain volumetrics and cognition in males and females

Most studies that have examined neuropsychological impairments associated with human immunodeficiency virus (HIV) have focused on males, yet females represent one of the largest groups of newly infected patients. Further, few studies have examined neuropsychological performance and neuroimaging outcomes among females compared to males in the modern era of highly active anti-retroviral therapy (HAART). The present study investigated neuropsychological performance and brain volumetrics among HIV+ males (n = 93) and females (n = 44) on stable HAART compared to HIV seronegative (HIV-) males (n = 42) and females (n = 49). Results revealed a significant effect of HIV on neuropsychological performance and neuroimaging measures. An effect of gender, independent of HIV status, was also observed for neuroimaging measures but not neuropsychological performance. Additionally, no significant differences in neuropsychological performance or brain volumetrics were seen between HIV+ males and females. No significant interaction was observed between HIV and gender on either neuropsychological or neuroimaging indices. Our results suggest that both HIV+ males and females treated with HAART experience similar outcomes in terms of brain integrity.

Facial emotion recognition impairments are associated with brain volume abnormalities in individuals with HIV

Impaired facial emotion recognition abilities in HIV+ patients are well documented, but little is known about the neural etiology of these difficulties. We examined the relation of facial emotion recognition abilities to regional brain volumes in 44 HIV-positive (HIV+) and 44 HIV-negative control (HC) adults. Volumes of structures implicated in HIV-associated neuropathology and emotion recognition were measured on MRI using an automated segmentation tool. Relative to HC, HIV+ patients demonstrated emotion recognition impairments for fearful expressions, reduced anterior cingulate cortex (ACC) volumes, and increased amygdala volumes. In the HIV+ group, fear recognition impairments correlated significantly with ACC, but not amygdala volumes. ACC reductions were also associated with lower nadir CD4 levels (i.e., greater HIV-disease severity). These findings extend our understanding of the neurobiological substrates underlying an essential social function, facial emotion recognition, in HIV+ individuals and implicate HIV-related ACC atrophy in the impairment of these abilities.

HIV clades B and C are associated with reduced brain volumetrics

The human immunodeficiency virus (HIV) has multiple genetic clades with varying prevalence throughout the world. Both HIV clade C (HIV-C) and HIV clade B (HIV-B) can cause cognitive impairment, but it is unclear if these clades are characterized by similar patterns of brain dysfunction. We examined brain volumetrics and neuropsychological performance among highly active antiretroviral therapy (HAART)-naïve HIV-B and HIV-C participants. Thirty-four HAART-naïve HIV-infected (HIV+) participants [17 HIV-B (USA); 17 HIV-C (South Africa)] and 34 age- and education-matched HIV-uninfected (HIV−) participants were evaluated. All participants underwent similar laboratory, neuropsychological, and neuroimaging studies. Brain volume measures were assessed within the caudate, putamen, amygdala, thalamus, hippocampus, corpus callosum, and cortical (gray and white matter) structures. A linear model that included HIV status, region, and their interaction assessed the effects of the virus on brain volumetrics. HIV− and HIV+ individuals were similar in age. On laboratory examination, HIV-C participants had lower CD4 cell counts and higher plasma HIV viral loads than HIV-B individuals. In general, HIV+ participants performed significantly worse on neuropsychological measures of processing speed and memory and had significantly smaller relative volumetrics within the thalamus, hippocampus, corpus callosum, and cortical gray and white matter compared to the respective HIV− controls. Both HIV-B and HIV-C are associated with similar volumetric declines when compared to matched HIV− controls. HIV-B and HIV-C were associated with significant reductions in brain volumetrics and poorer neuropsychological performance; however, no specific effect of HIV clade subtype was evident. These findings suggest that HIV-B and HIV-C both detrimentally affect brain integrity.