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1.
Med Care ; 62(8): 549-558, 2024 Aug 01.
Article in English | MEDLINE | ID: mdl-38967995

ABSTRACT

BACKGROUND: The Veterans Health Administration (VHA) has initiatives underway to enhance the provision of care coordination (CC), particularly among high-risk Veterans. Yet, evidence detailing the characteristics of and who receives VHA CC is limited. OBJECTIVES: We examined intensity, timing, setting, and factors associated with VHA CC among high-risk Veterans. RESEARCH DESIGN: We conducted a retrospective observational cohort study, following Veterans for 1 year after being identified as high-risk for hospitalization or mortality, to characterize their CC. Demographic and clinical factors predictive of CC were identified via multivariate logistic regression. SUBJECTS: A total of 1,843,272 VHA-enrolled high-risk Veterans in fiscal years 2019-2021. MEASURES: We measured 5 CC variables during the year after Veterans were identified as high risk: (1) receipt of any service, (2) number of services received, (3) number of days to first service, (4) number of days between services, and (5) type of visit during which services were received. RESULTS: Overall, 31% of high-risk Veterans in the sample received CC during one-year follow-up. Among Veterans who received ≥1 service, a median of 2 [IQR (1, 6)] services were received. Among Veterans who received ≥2 services, there was a median of 26 [IQR (10, 57)] days between services. Most services were received during outpatient psychiatry (46%) or medicine (16%) visits. Veterans' sociodemographic and clinical characteristics were associated with receipt of CC. CONCLUSIONS: A minority of Veterans received CC in the year after being identified as high-risk, and there was variation in intensity, timing, and setting of CC. Research is needed to examine the fit between Veterans' CC needs and preferences and VHA CC delivery.


Subject(s)
United States Department of Veterans Affairs , Veterans , Humans , United States , Male , Female , United States Department of Veterans Affairs/statistics & numerical data , Retrospective Studies , Middle Aged , Veterans/statistics & numerical data , Aged , Adult , Continuity of Patient Care/statistics & numerical data , Veterans Health Services/statistics & numerical data
2.
J Gen Intern Med ; 39(4): 626-635, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37884839

ABSTRACT

BACKGROUND: Negative mental health-related effects of SARS-COV-2 infection are increasingly evident. However, the impact on suicide-related outcomes is poorly understood, especially among populations at elevated risk. OBJECTIVE: To determine risk of suicide attempts and other self-directed violence (SDV) after SARS-COV-2 infection in a high-risk population. DESIGN: We employed an observational design supported by comprehensive electronic health records from the Veterans Health Administration (VHA) to examine the association of SARS-COV-2 infection with suicide attempts and other SDV within one year of infection. Veterans with SARS-COV-2 infections were matched 1:5 with non-infected comparators each month. Three periods after index were evaluated: days 1-30, days 31-365, and days 1-365. PARTICIPANTS: VHA patients infected with SARS-COV-2 between March 1, 2020 and March 31, 2021 and matched non-infected Veteran comparators. MAIN MEASURES: Suicide attempt and other SDV events for the COVID-19 and non-infected comparator groups were analyzed using incidence rates per 100,000 person years and hazard ratios from Cox regressions modeling time from matched index date to first event. Subgroups were also examined. KEY RESULTS: 198,938 veterans with SARS-COV-2 (COVID-19 group) and 992,036 comparators were included. Unadjusted one-year incidence per 100,000 for suicide attempt and other SDV was higher among the COVID-19 group: 355 vs 250 and 327 vs 235, respectively. The COVID-19 group had higher risk than comparators for suicide attempts: days 1-30 hazard ratio (HR) = 2.54 (CI:2.05, 3.15), days 31-365 HR = 1.30 (CI:1.19, 1.43) and days 1-365 HR = 1.41 (CI:1.30, 1.54), and for other SDV: days 1-30 HR = 1.94 (CI:1.51, 2.49), days 31-365 HR = 1.32 (CI:1.20, 1.45) and days 1-365 HR = 1.38 (CI:1.26, 1.51). CONCLUSIONS: COVID-19 patients had higher risks of both suicide attempts and other forms of SDV compared to uninfected comparators, which persisted for at least one year after infection. Results support suicide risk screening of those infected with SARS-COV-2 to identify opportunities to prevent self-harm.


Subject(s)
COVID-19 , Veterans , Humans , SARS-CoV-2 , Suicide, Attempted , Electronic Health Records
3.
Prev Med ; 185: 108051, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38906274

ABSTRACT

BACKGROUND: Current measures of condition-specific disabilities or those capturing only severe limitations may underestimate disability prevalence, including among Veterans. OBJECTIVES: To develop a comprehensive measure to characterize and compare disabilities among US Veterans and non-Veterans. METHODS: Using 2015-2018 pooled cross-sectional National Health Interview Survey data, we compared the frequency and survey-weighted prevalence of non-mutually exclusive sensory, social, and physical disabilities by Veteran status. We developed a measure for and examined the frequency and survey-weighted prevalence of eight mutually exclusive disability categories-sensory only; physical only; social only; sensory and physical; social and sensory; physical and social; and sensory, social, and physical. RESULTS: Among 118,818 NHIS respondents, 11,943 were Veterans. Veterans had a greater prevalence than non-Veterans of non-mutually exclusive physical [52.01% vs. 34.68% (p < 0.001)], sensory [44.47% vs. 21.79% (p < 0.001)], and social [17.20% vs. 11.61% (p < 0.001)] disabilities (after survey-weighting). The most frequently reported mutually exclusive disability categories for both Veterans and non-Veterans were sensory and physical (19.20% and 8.02%, p < 0.001) and physical only (16.24% and 15.69%, p = 0.216) (after survey-weighting). The least frequently reported mutually exclusive disability categories for both Veterans and non-Veterans were social only (0.31% and 0.44%, p = 0.136) and sensory and social (0.32% and 0.20%, respectively, 0.026) (after survey-weighting). CONCLUSIONS: Our disability metric demonstrates that Veterans have a higher disability prevalence than non-Veterans, and a higher prevalence than previously reported. Public policy and future research should consider this broader definition of disability to more fully account for the variable needs of people with disabilities.


Subject(s)
Disability Evaluation , Disabled Persons , Health Surveys , Veterans , Humans , Male , Female , Veterans/statistics & numerical data , Disabled Persons/statistics & numerical data , United States/epidemiology , Middle Aged , Cross-Sectional Studies , Prevalence , Adult , Aged , Young Adult
4.
BMC Health Serv Res ; 24(1): 943, 2024 Aug 19.
Article in English | MEDLINE | ID: mdl-39160528

ABSTRACT

BACKGROUND: Research suggests an association between COVID-19 infection and certain financial hardships in the shorter term and among single-state and privately insured samples. Whether COVID-19 is associated with financial hardship in the longer-term or among socially vulnerable populations is unknown. Therefore, we examined whether COVID-19 was associated with a range of financial hardships 18 months after initial infection among a national cohort of Veterans enrolled in the Veterans Health Administration (VHA)-the largest national integrated health system in the US. We additionally explored the association between Veteran characteristics and financial hardship during the pandemic, irrespective of COVID-19. METHODS: We conducted a prospective, telephone-based survey. Out of 600 Veterans with COVID-19 from October 2020 through April 2021 who were invited to participate, 194 Veterans with COVID-19 and 194 matched comparators without a history of infection participated. Financial hardship outcomes included overall health-related financial strain, two behavioral financial hardships (e.g., taking less medication than prescribed due to cost), and seven material financial hardships (e.g., using up most or all savings). Weighted generalized estimating equations were used to estimate risk ratios (RR) and 95% confidence intervals (CI) of financial hardship by COVID-19 status, and to assess the relationship between infection and Veteran age, VHA copay status, and comorbidity score, irrespective of COVID-19 status. RESULTS: Among 388 respondents, 67% reported at least one type of financial hardship since March 2020, with 21% reporting behavioral hardships and 64% material hardships; 8% reported severe-to-extreme health-related financial strain. Compared with uninfected matched comparators, Veterans with a history of COVID-19 had greater risks of severe-to-extreme health-related financial strain (RR: 4.0, CI: 1.4-11.2), taking less medication due to cost (RR: 2.9, 95% CI: 1.0-8.6), and having a loved one take time off work to care for them (RR: 1.9, CI: 1.1-3.6). Irrespective of COVID-19 status, Veterans aged < 65 years had a greater risk of most financial hardships compared with Veterans aged ≥ 65 years. CONCLUSIONS: Health-related financial hardships such as taking less medication due to cost and severe-to-extreme health-related financial strain were more common among Veterans with a history of COVID-19 than among matched comparators. Strategies are needed to address health-related financial hardship after COVID-19. TRIAL REGISTRATION: NCT05394025, registered 05-27-2022.


Subject(s)
COVID-19 , Financial Stress , Veterans , Humans , COVID-19/epidemiology , COVID-19/economics , United States/epidemiology , Prospective Studies , Male , Female , Veterans/statistics & numerical data , Middle Aged , Financial Stress/epidemiology , Aged , SARS-CoV-2 , Adult , Pandemics/economics , United States Department of Veterans Affairs
5.
Mol Psychiatry ; 27(1): 220-229, 2022 01.
Article in English | MEDLINE | ID: mdl-34117366

ABSTRACT

Dopamine system deficiencies and associated behavioral phenotypes may be a critical barrier to success in treating stimulant use disorders. Similarities in dopamine dysfunction between cocaine and methamphetamine use disorder but also key differences may impact treatment efficacy and outcome. This review will first compare the epidemiology of cocaine and methamphetamine use disorder. A detailed account of the pharmacokinetic and pharmacodynamic properties associated with each drug will then be discussed, with an emphasis on effects on the dopamine system and associated signaling pathways. Lastly, treatment results from pharmacological clinical trials will be summarized along with a more comprehensive review of the involvement of the trace amine-associated receptor on dopamine signaling dysfunction among stimulants and its potential as a therapeutic target.


Subject(s)
Central Nervous System Stimulants , Cocaine , Methamphetamine , Central Nervous System Stimulants/pharmacology , Cocaine/pharmacology , Dopamine/metabolism , Methamphetamine/metabolism
6.
J Neurovirol ; 24(6): 738-751, 2018 12.
Article in English | MEDLINE | ID: mdl-30298201

ABSTRACT

Hepatitis C virus-infected (HCV+) adults evidence increased rates of psychiatric and cognitive difficulties. This is the first study to use functional magnetic resonance imaging (fMRI) to examine brain activation in untreated HCV+ adults. To determine whether, relative to non-infected controls (CTLs), HCV+ adults exhibit differences in brain activation during a delay discounting task (DDT), a measure of one's tendency to choose smaller immediate rewards over larger delayed rewards-one aspect of impulsivity. Twenty adults with HCV and 26 CTLs completed an fMRI protocol during the DDT. Mixed effects regression analyses of hard versus easy trials of the DDT showed that, compared with CTLs, the HCV+ group exhibited less activation in the left lateral occipital gyrus, precuneus, and superior frontal gyrus. There were also significant interactive effects for hard-easy contrasts in the bilateral medial frontal gyrus, left insula, left precuneus, left inferior parietal lobule, and right temporal occipital gyrus; the CTL group evidenced a positive relationship between impulsivity and activation, while the HCV+ group exhibited a negative relationship. Within the HCV+ group, those with high viral load chose immediate rewards more often than those with low viral load, regardless of choice difficulty; those with low viral load chose immediate rewards more often on hard choices relative to easy choices. Results show that HCV+ patients exhibit greater impulsive behavior when presented with difficult choices, and impulsivity is negatively related to activation in regions important for cognitive control. Thus, interventions that decrease impulsive choice may be warranted with some HCV+ patients.


Subject(s)
Brain/physiopathology , Delay Discounting/physiology , Hepatitis C/psychology , Adult , Aged , Female , Hepatitis C/complications , Hepatitis C/physiopathology , Humans , Magnetic Resonance Imaging , Male , Middle Aged
7.
Health Aff Sch ; 2(6): qxae075, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38938272

ABSTRACT

Geographic variation in hardship, especially health-related hardship, was identified prior to and during the pandemic, but we do not know whether this variation is consistent among Veterans Health Administration (VHA)-enrolled veterans, who reported markedly high rates of financial hardship during the pandemic, despite general and veteran-specific federal policy efforts aimed at reducing hardship. In a nationwide, regionally stratified sample of VHA-enrolled veterans, we examined whether the prevalence of financial hardship during the pandemic varied by US Census region. We found veterans in the South, compared with those in other census regions, reported higher rates of severe-to-extreme financial strain, using up all or most of their savings, being unable to pay for necessities, being contacted by collections, and changing their employment due to the kind of work they could perform. Regional variation in veteran financial hardship demonstrates a need for further research about the role and interaction of federal and state financial-assistance policies in shaping risks for financial hardship as well as potential opportunities to mitigate risks among veterans and reduce variation across regions.

8.
JAMA Netw Open ; 7(4): e245786, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38598237

ABSTRACT

Importance: Research demonstrates that SARS-CoV-2 infection is associated with increased risk of all-cause hospitalization. However, no prior studies have assessed the association between SARS-CoV-2 and potentially preventable hospitalizations-that is, hospitalizations for conditions that can usually be effectively managed in ambulatory care settings. Objective: To examine whether SARS-CoV-2 is associated with potentially preventable hospitalization in a nationwide cohort of US veterans. Design, Setting, and Participants: This cohort study used an emulated target randomized trial design with monthly sequential trials to compare risk of a potentially preventable hospitalization among veterans with SARS-CoV-2 and matched comparators without SARS-CoV-2. A total of 189 136 US veterans enrolled in the Veterans Health Administration (VHA) who were diagnosed with SARS-CoV-2 between March 1, 2020, and April 30, 2021, and 943 084 matched comparators were included in the analysis. Data were analyzed from May 10, 2023, to January 26, 2024. Exposure: SARS-CoV-2 infection. Main Outcomes and Measures: The primary outcome was a first potentially preventable hospitalization in VHA facilities, VHA-purchased community care, or Medicare fee-for-service care. Extended Cox models were used to examine adjusted hazard ratios (AHRs) of potentially preventable hospitalization among veterans with SARS-CoV-2 and comparators during follow-up periods of 0 to 30, 0 to 90, 0 to 180, and 0 to 365 days. The start of follow-up was defined as the date of each veteran's first positive SARS-CoV-2 diagnosis, with the same index date applied to their matched comparators. Results: The 1 132 220 participants were predominantly men (89.06%), with a mean (SD) age of 60.3 (16.4) years. Most veterans were of Black (23.44%) or White (69.37%) race. Veterans with SARS-CoV-2 and comparators were well-balanced (standardized mean differences, all <0.100) on observable baseline clinical and sociodemographic characteristics. Overall, 3.10% of veterans (3.81% of those with SARS-CoV-2 and 2.96% of comparators) had a potentially preventable hospitalization during 1-year follow-up. Risk of a potentially preventable hospitalization was greater among veterans with SARS-CoV-2 than comparators in 4 follow-up periods: 0- to 30-day AHR of 3.26 (95% CI, 3.06-3.46); 0- to 90-day AHR of 2.12 (95% CI, 2.03-2.21); 0- to 180-day AHR of 1.69 (95% CI, 1.63-1.75); and 0- to 365-day AHR of 1.44 (95% CI, 1.40-1.48). Conclusions and Relevance: In this cohort study, an increased risk of preventable hospitalization in veterans with SARS-CoV-2, which persisted for at least 1 year after initial infection, highlights the need for research on ways in which SARS-CoV-2 shapes postinfection care needs and engagement with the health system. Solutions are needed to mitigate preventable hospitalization after SARS-CoV-2.


Subject(s)
COVID-19 , Aged , Female , Humans , Male , Middle Aged , Cohort Studies , COVID-19/epidemiology , COVID-19 Testing , Hospitalization , Medicare , SARS-CoV-2 , United States/epidemiology , Veterans
9.
Front Health Serv ; 3: 1211577, 2023.
Article in English | MEDLINE | ID: mdl-37654810

ABSTRACT

Background: For patients with complex health and social needs, care coordination is crucial for improving their access to care, clinical outcomes, care experiences, and controlling their healthcare costs. However, evidence is inconsistent regarding the core elements of care coordination interventions, and lack of standardized processes for assessing patients' needs has made it challenging for providers to optimize care coordination based on patient needs and preferences. Further, ensuring providers have reliable and timely means of communicating about care plans, patients' full spectrum of needs, and transitions in care is important for overcoming potential care fragmentation. In the Veterans Health Administration (VA), several initiatives are underway to implement care coordination processes and services. In this paper, we describe our study underway in the VA aimed at building evidence for designing and implementing care coordination practices that enhance care integration and improve health and care outcomes for Veterans with complex care needs. Methods: In a prospective observational multiple methods study, for Aim 1 we will use existing data to identify Veterans with complex care needs who have and have not received care coordination services. We will examine the relationship between receipt of care coordination services and their health outcomes. In Aim 2, we will adapt the Patient Perceptions of Integrated Veteran Care questionnaire to survey a sample of Veterans about their experiences regarding coordination, integration, and the extent to which their care needs are being met. For Aim 3, we will interview providers and care teams about their perceptions of the innovation attributes of current care coordination needs assessment tools and processes, including their improvement over other approaches (relative advantage), fit with current practices (compatibility and innovation fit), complexity, and ability to visualize how the steps proceed to impact the right care at the right time (observability). The provider interviews will inform design and deployment of a widescale provider survey. Discussion: Taken together, our study will inform development of an enhanced care coordination intervention that seeks to improve care and outcomes for Veterans with complex care needs.

10.
J Clin Exp Neuropsychol ; 43(6): 599-610, 2021 08.
Article in English | MEDLINE | ID: mdl-34612792

ABSTRACT

OBJECTIVE: To evaluate whether cognitive performance in adults with active methamphetamine use (MA-ACT) differs from cognitive performance in adults in remission from MA use disorder (MA-REM) and adults without a history of substance use disorder (CTLs). METHOD: MA-ACT (n = 36), MA-REM (n = 48), and CTLs (n = 62) completed the Neuropsychological Assessment Battery (NAB). RESULTS: The MA-ACT group did not perform significantly worse than CTLs on any NAB Index. The MA-REM group performed significantly (p < 0.050) worse than CTLs on the NAB Memory Index. The MA-ACT group performed significantly better than CTLs and the MA-REM group on the Executive Functions Index. CONCLUSIONS: Some cognitive deficits are apparent during remission from MA use, but not during active use; this may result in clinical challenges for adults attempting to maintain recovery and continue with treatment.


Subject(s)
Amphetamine-Related Disorders , Methamphetamine , Adult , Amphetamine-Related Disorders/complications , Cognition , Executive Function , Humans , Methamphetamine/adverse effects , Neuropsychological Tests
11.
Front Psychiatry ; 11: 90, 2020.
Article in English | MEDLINE | ID: mdl-32180738

ABSTRACT

Methamphetamine use and psychopathy are associated with criminal behavior; however, it is unclear how methamphetamine use and psychopathy interact to promote violent, economic and drug offenses. Abnormalities in corticostriatal functional connectivity are exhibited in both psychopathic and methamphetamine dependent individuals, which may contribute to criminal behavior through maladaptive and impulsive decision-making processes. This study shows that psychopathic traits contribute to weaker corticostriatal connectivity in methamphetamine dependence and contributes to an increase in criminal behavior. As the propensity to engage in criminal activity is dependent on a number of factors, a hierarchical regression identifies the contribution of the impulsive antisocial domain of psychopathy, anxiety, years of methamphetamine use and corticostriatal connectivity on different types of criminal offenses. Methamphetamine use and psychopathic traits reduce treatment responsiveness and increase the likelihood of recidivism, and it is therefore important to understand the factors underlying the propensity to engage in criminal behavior.

12.
Psychopharmacology (Berl) ; 237(1): 263-278, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31673722

ABSTRACT

RATIONALE: Alcohol-use disorder (AUD) is associated with the propensity to choose smaller sooner options on the delay discounting task. It is unclear, however, how inherent risk underlies delay discounting behavior. As impulsive choice is a hallmark feature in AUD, it is important to understand the neural response to reward and delay while accounting for risk in impulsive decision-making. OBJECTIVE: This study examined activation associated with delay and reward magnitude, while controlling for risk in a probabilistic delay discounting task in AUD and examined if differences in activation were associated with treatment outcomes. METHODS: Thirty-nine recently abstinent alcohol-dependent volunteers and 46 controls completed a probabilistic delay discounting task paired with functional magnetic resonance imaging. Alcohol use was collected using a self-report journal for 3 months following baseline scan. RESULTS: During delay stimulus presentations, Controls exhibited greater activation compared to the Alcohol group notably in the anterior insula, middle/dorsal anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (PFC), and inferior parietal lobule. For magnitude, the Alcohol group exhibited greater activation than Controls primarily in medial PFC, rostral ACC, left posterior parietal cortex, and right precuneus. Within the Alcohol group, alcohol craving severity negatively correlated with right lateral PFC activation during reward magnitude in individuals who completed the 3-month study without relapse, while non-completers showed the opposite relationship. CONCLUSIONS: The results of this study extend previous findings that alcohol use disorder is associated with differences in activation during an immediate or delayed choice by delineating activation associated with the parameters of impulsive choice.


Subject(s)
Alcoholism/diagnostic imaging , Brain/diagnostic imaging , Delay Discounting/physiology , Reward , Adult , Alcoholism/physiopathology , Brain/physiopathology , Decision Making , Female , Humans , Impulsive Behavior/physiology , Magnetic Resonance Imaging/methods , Male , Middle Aged
13.
Psychopharmacology (Berl) ; 237(1): 279, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31863122

ABSTRACT

After publication of this paper, the authors determined an error in the funding information section CX17008-CDA2 should be CX001790 (MK).

14.
Front Psychiatry ; 10: 603, 2019.
Article in English | MEDLINE | ID: mdl-31551824

ABSTRACT

Naltrexone attenuates craving, and the subjective effects of methamphetamine and extended-release naltrexone (XR-NTX) reduces functional connectivity between regions of the striatum and limbic cortex. Naltrexone modulates neural activity at dopaminergic synapses; however, it is unclear whether naltrexone has an effect on large-scale brain networks. Functional networks interact to coordinate behavior, and as substance-use disorders are associated with an imbalance between reward and cognitive control networks, treatment approaches that target interactive brain systems underlying addiction may be a useful adjunct for behavioral therapies. The objective of this study was to examine the effect of XR-NTX on large-scale brain networks and to determine whether changes in network relationships attenuate drug use, craving, and addiction severity. Thirty-nine participants in or seeking treatment for methamphetamine-use disorder were enrolled in a clinical trial of XR-NTX between May 2013 and March 2015 (Clinicaltrials.gov NCT01822132). Functional magnetic resonance imaging (fMRI) and questionnaires were conducted before and after double-blinded randomization to a 4-week injection of XR-NTX or placebo. In the XR-NTX group, methamphetamine use was reduced along with a decrease in the coupling between executive control (ECN) and default mode (DMN) networks. As decoupling of ECN and DMN networks was associated with change in the severity of dependence, the results suggest that XR-NTX may modulate and enhance ECN attentional resources and suppress DMN self-referential and emotional processing. This study identifies the effect of naltrexone on changes in the intrinsic functional coupling of large-scale brain networks and provides a more systematic understanding of how large-scale networks interact to promote behavioral change in methamphetamine-use disorder.

15.
Pharmacol Biochem Behav ; 179: 34-42, 2019 04.
Article in English | MEDLINE | ID: mdl-30695700

ABSTRACT

Addiction is a worldwide public health problem and this article reviews scientific advances in identifying the role of neuroinflammation in the genesis, maintenance, and treatment of substance use disorders. With an emphasis on neuroimaging techniques, this review examines human studies of addiction using positron emission tomography to identify binding of translocator protein (TSPO), which is upregulated in reactive glial cells and activated microglia during pathological states. High TSPO levels have been shown in methamphetamine use but exhibits variable patterns in cocaine use. Alcohol and nicotine use, however, are associated with lower TSPO levels. We discuss how mechanistic differences at the neurotransmitter and circuit level in the neural effects of these agents and subsequent immune response may explain these observations. Finally, we review the potential of anti-inflammatory drugs, including ibudilast, minocycline, and pioglitazone, to ameliorate the behavioral and cognitive consequences of addiction.


Subject(s)
Central Nervous System Diseases/etiology , Inflammation/etiology , Substance-Related Disorders/complications , Central Nervous System Diseases/diagnostic imaging , Humans , Inflammation/diagnostic imaging , Positron-Emission Tomography
16.
Neurosci Lett ; 677: 49-54, 2018 06 11.
Article in English | MEDLINE | ID: mdl-29689344

ABSTRACT

Methamphetamine (MA) causes an increase in pro-inflammatory cytokines in animal models and in humans. Resulting activation of microglia and neuro-inflammation could, via effects on reward networks, mediate behavioral characteristics of addiction. We examined the relationship between interleukin-6 (IL-6) and corticolimbic and striatolimbic resting-state functional connectivity (RSFC). Thirty adults diagnosed with MA dependence and 20 control subjects underwent a resting-state functional magnetic resonance imaging (fMRI) scan and gave a blood sample for determination of plasma IL-6 levels. Seed-based RSFC analyses were performed to examine the interactive effect of group and IL-6 on ventral striatal and prefrontal connectivity. Within the MA group, IL-6 levels were positively related to striatolimbic RSFC but negatively related to corticostriatal RSFC. Our findings with IL-6 support the idea that inflammation may at least partly mediate the link among MA use disorder, RSFC, and behavior, possibly via effects on mesolimbic and mesocortical dopaminergic systems.


Subject(s)
Amphetamine-Related Disorders/physiopathology , Brain/drug effects , Brain/physiopathology , Inflammation/chemically induced , Interleukin-6/blood , Methamphetamine/adverse effects , Adult , Amphetamine-Related Disorders/complications , Brain Mapping , Female , Humans , Inflammation/blood , Magnetic Resonance Imaging , Male , Neural Pathways/drug effects , Neural Pathways/physiopathology
17.
Drug Alcohol Depend ; 192: 186-192, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30266003

ABSTRACT

OBJECTIVE: Naltrexone has been shown to attenuate craving and the subjective effects of methamphetamine. Although naltrexone has modulatory effects on neural activity at dopaminergic synapses, the effect on striatal connectivity is unclear. As methamphetamine use is associated with greater resting-state functional connectivity (RSFC) in the dopaminergic system, we examined whether extended-release naltrexone (XR-NTX) can normalize striatal connectivity and whether changes in RSFC are associated with changes in craving and methamphetamine use. METHODS: Thirty-seven participants in or seeking treatment for methamphetamine use disorder took part in this clinical trial at a university-based research clinic between May 2013 and March 2015 (Clinicaltrials.gov NCT01822132). Participants were randomized by a random number generator to a single four-week injection of XR-NTX or placebo. Functional magnetic resonance imaging (fMRI) and self-reported measures of craving and methamphetamine use were conducted before and after double-blinded randomization. FINDINGS: There was a significant reduction in methamphetamine use in the naltrexone group and a significant treatment-by-time interaction on RSFC between the ventral striatum, amygdala, hippocampus, and midbrain. Connectivity was significantly reduced over time in participants randomized to naltrexone but unchanged in those randomized to placebo (p < 0.05, whole-brain corrected). Interactions between treatment and changes in connectivity show that significant reductions in connectivity were associated with reductions in methamphetamine use. CONCLUSIONS: Neurobiological deficits associated with methamphetamine use may undermine the efficacy of pharmacotherapies that directly target the dopamine reward system. Naltrexone, via antagonism of indirect mu-opioid effects on dopamine neurons, may attenuate reward system connectivity and aid in methamphetamine use treatment.


Subject(s)
Amphetamine-Related Disorders/diagnostic imaging , Magnetic Resonance Imaging , Methamphetamine/adverse effects , Naltrexone/therapeutic use , Narcotic Antagonists/therapeutic use , Ventral Striatum/diagnostic imaging , Adult , Amphetamine-Related Disorders/drug therapy , Amygdala/diagnostic imaging , Amygdala/drug effects , Amygdala/physiology , Delayed-Action Preparations , Female , Hippocampus/diagnostic imaging , Hippocampus/drug effects , Hippocampus/physiology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Naltrexone/pharmacology , Narcotic Antagonists/pharmacology , Neural Pathways/diagnostic imaging , Neural Pathways/drug effects , Neural Pathways/physiology , Rest/physiology , Ventral Striatum/drug effects , Ventral Striatum/physiology
18.
Front Psychiatry ; 8: 182, 2017.
Article in English | MEDLINE | ID: mdl-28993741

ABSTRACT

Alterations within mesocorticolimbic terminal regions commonly occur with alcohol use disorder (AUD). As pathological drug-seeking behavior may arise as a consequence of alcohol-induced neuroadaptations, it is critical to understand how such changes increase the likelihood of relapse. This report examined resting-state functional connectivity (RSFC) using both a seed-based and model-free approach in individuals in treatment for AUD and how dysregulation of network connectivity contributes to treatment outcomes. In order to provide a mechanism by which neural networks promote relapse, interactive effects of mesocorticolimbic connectivity and AUD risk factors in treatment completers and non-completers were examined. AUD group showed stronger RSFC between striatum, insula, and anterior cingulate cortex than controls. Within the AUD group, non-completers compared to completers showed enhanced RSFC between (1) striatum-insula, (2) executive control network (ECN)-amygdala, and (3) basal ganglia/salience network and striatum, precuneus, and insula. Completers showed enhanced RSFC between striatum-right dorsolateral prefrontal cortex. Furthermore, completers and non-completers differed in relationships between RSFC and relapse risk factors, where non-completers exhibited positive associations between craving intensity and RSFC of striatum-insula and ECN-amygdala. These findings provide evidence for interactions between corticolimbic connectivity in AUD and craving and establish an important link between network connectivity and dynamic risk factors that contribute to relapse. Results demonstrate that relapse vulnerability is attributed to craving dysregulation manifested by enhanced connectivity in striato-limbic regions and diminished corticostriatal connectivity.

19.
J Agric Food Chem ; 56(18): 8565-73, 2008 Sep 24.
Article in English | MEDLINE | ID: mdl-18710247

ABSTRACT

The Varroa mite ( Varroa destructor) is becoming ubiquitous worldwide and is a serious threat to honey bees. The cultivation of certain food crops are at risk. The most noted acaricides against Varroa mites are tau-fluvaninate and coumaphos, but the mites are showing resistance. Since these insecticides are used in the proximity of honey, it is desirable to use natural alternatives. Monoterpenoids such as thymol and carvacrol, that are constituents of oil of thyme and oil of origanum, show promise as acaricides against the Varroa mite ( Varroa destructor), but the delivery of these compounds remains a challenge due to the low water solubility and uncontrolled release into the colony. Beta-cyclodextrin (beta-CD) inclusion complexes of thymol, oil of origanum, and carvacrol were prepared on a preparative scale. Competitive binding was studied by fluorescence spectroscopy by using 6- p-toluidinylnaphthalene-2-sulfonate as a fluorescent probe. The complexes were characterized, and the competitive binding described by (1)H and (13)C NMR spectroscopy chemical shifts. The toxicity of beta-CD and the prepared complexes in enriched sucrose syrup was studied by conducting caged honey bee ( Apis mellifera) feeding trials. After the first and second weeks of feeding, hemolymph and gut tissue samples were acquired from the caged bee study. The levels of thymol and carvacrol were quantified by solid-phase microextraction gas chromatography mass spectroscopy, using an optimized procedure we developed. High (mM) levels of thymol and carvacrol were detected in bee tissues without any imposed toxicity to the bees, in an effort to deter Varroa mites from feeding on honey bee hemolymph.


Subject(s)
Bees/parasitology , Hemolymph , Insecticides/administration & dosage , Mites , Monoterpenes/administration & dosage , beta-Cyclodextrins/administration & dosage , Animals , Drug Carriers/administration & dosage
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