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1.
JMIR Ment Health ; 11: e49916, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38753416

RESUMO

BACKGROUND: The care environment significantly influences the experiences of patients with severe mental illness and the quality of their care. While a welcoming and stimulating environment enhances patient satisfaction and health outcomes, psychiatric facilities often prioritize staff workflow over patient needs. Addressing these challenges is crucial to improving patient experiences and outcomes in mental health care. OBJECTIVE: This study is part of the Patient-Reported Experience Measure for Improving Quality of Care in Mental Health (PREMIUM) project and aims to establish an item bank (PREMIUM-CE) and to develop computerized adaptive tests (CATs) to measure the experience of the care environment of adult patients with schizophrenia, bipolar disorder, or major depressive disorder. METHODS: We performed psychometric analyses including assessments of item response theory (IRT) model assumptions, IRT model fit, differential item functioning (DIF), item bank validity, and CAT simulations. RESULTS: In this multicenter cross-sectional study, 498 patients were recruited from outpatient and inpatient settings. The final PREMIUM-CE 13-item bank was sufficiently unidimensional (root mean square error of approximation=0.082, 95% CI 0.067-0.097; comparative fit index=0.974; Tucker-Lewis index=0.968) and showed an adequate fit to the IRT model (infit mean square statistic ranging between 0.7 and 1.0). DIF analysis revealed no item biases according to gender, health care settings, diagnosis, or mode of study participation. PREMIUM-CE scores correlated strongly with satisfaction measures (r=0.69-0.78; P<.001) and weakly with quality-of-life measures (r=0.11-0.21; P<.001). CAT simulations showed a strong correlation (r=0.98) between CAT scores and those of the full item bank, and around 79.5% (396/498) of the participants obtained a reliable score with the administration of an average of 7 items. CONCLUSIONS: The PREMIUM-CE item bank and its CAT version have shown excellent psychometric properties, making them reliable measures for evaluating the patient experience of the care environment among adults with severe mental illness in both outpatient and inpatient settings. These measures are a valuable addition to the existing landscape of patient experience assessment, capturing what truly matters to patients and enhancing the understanding of their care experiences. TRIAL REGISTRATION: ClinicalTrials.gov NCT02491866; https://clinicaltrials.gov/study/NCT02491866.


Assuntos
Transtornos Mentais , Psicometria , Humanos , Masculino , Psicometria/métodos , Psicometria/instrumentação , Feminino , Adulto , Pessoa de Meia-Idade , Estudos Transversais , Transtornos Mentais/terapia , Transtornos Mentais/diagnóstico , Satisfação do Paciente , Medidas de Resultados Relatados pelo Paciente , Reprodutibilidade dos Testes , Inquéritos e Questionários
2.
Sante Publique ; 36(1): 33-44, 2024 04 05.
Artigo em Francês | MEDLINE | ID: mdl-38580465

RESUMO

INTRODUCTION: A multi-center observational study was carried out in ten ESMS, using a mixed methodology (site visits, questionnaire survey, semi-directive group interviews with professionals and individual interviews with users). PURPOSE OF THE RESEARCH: The aim of this article is to describe the management and prevention of smoking in ESMS for people with mental health disorders, and to characterize and identify the smoking behaviors and representations of ESMS users and the professionals working there. RESULTS: The study made it possible to distinguish between ESMS in terms of the organization of smoking areas and tobacco prevention initiatives. It also revealed that 37 percent of respondents among the professionals said they smoked tobacco, with some of them explaining that they smoked with users and sometimes gave them cigarettes. With regard to prevention, there was a consensus among professionals that they should help users who wanted to stop smoking. Professionals were divided, however, on the need for more active prevention, citing the users' freedom and the fact that ESMS are places where people live. Among the users, 47 percent said they were smokers. Of the users who smoked, 55 percent said they wanted to stop. Interviews with the users revealed that twelve of them wanted to quit, with some asking for help and more assistance from professionals. CONCLUSIONS: This report suggests that intervention research could be developed in ESMS for people with mental health disorders, who could benefit from the smoking prevention actions identified in the facilities and services investigated.


Introduction: Une étude observationnelle multicentrique a été réalisée dans dix ESMS et mobilisait une méthodologie mixte (visite des structures, enquête par questionnaires, entretiens semi-directifs collectifs avec des professionnels et individuels avec des usagers). But de l'étude: Cet article vise à décrire la gestion et la prévention du tabagisme dans des établissements et services médico-sociaux (ESMS) accueillant des personnes avec un trouble psychique, et à caractériser et identifier les comportements tabagiques et les représentations de leurs usagers et professionnels. Résultats: L'étude a permis de distinguer les ESMS au regard de l'organisation des espaces du tabagisme et des actions de prévention du tabac. Elle a permis également de constater que 37 % des professionnels qui ont répondu déclaraient fumer du tabac, une partie d'entre eux expliquant fumer avec les usagers et leur donner parfois des cigarettes. Concernant la prévention, un consensus se dégageait chez les professionnels sur le fait d'aider les usagers qui souhaitaient arrêter. Les professionnels étaient cependant divisés à l'égard d'une prévention plus active, invoquant la liberté de l'usager et le fait que les ESMS sont des lieux de vie. 47 % des usagers se disaient fumeurs. 55 % des usagers fumeurs déclaraient vouloir arrêter. Les entretiens avec les usagers ont permis de constater que douze d'entre eux souhaitaient arrêter, une partie réclamant de l'aide et d'être davantage aidés par les professionnels. Conclusions: Cet état des lieux invite à développer des recherches interventionnelles dans les ESMS accueillant des personnes avec un trouble psychique qui pourraient tirer profit des actions de prévention du tabac repérées dans des structures enquêtées.


Assuntos
Abandono do Hábito de Fumar , Humanos , Abandono do Hábito de Fumar/métodos , Fumar/psicologia , Fumar Tabaco , Inquéritos e Questionários , Prevenção do Hábito de Fumar
3.
Psychiatry Res ; 328: 115444, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37677894

RESUMO

Severe mental illness (SMI) patients often have complex health needs, which makes it difficult to access and coordinate their care. This study aimed to develop a computerized adaptive testing (CAT) tool, PREMIUM CAT-ACC, to measure SMI patients' experience with access and care coordination. This multicenter and cross-sectional study included 496 adult in- and out-patients with SMI (i.e., schizophrenia, bipolar disorder, or major depressive disorder). Psychometric analysis of the 13-item bank showed adequate properties, with preliminary evidence of external validity and no substantial differential item functioning for sex, age, care setting, and diagnosis, making it suitable for CAT administration. A post-hoc CAT simulation demonstrated that the tool was efficient and accurate, with an average of seven items, compared to the full item bank administration. Its use by clinicians can contribute to optimizing patient care pathways and transitioning towards more person-centered healthcare.


Assuntos
Transtorno Bipolar , Transtorno Depressivo Maior , Transtornos Mentais , Adulto , Humanos , Estudos Transversais , Teste Adaptativo Computadorizado , Transtornos Mentais/diagnóstico , Transtornos Mentais/terapia , Transtorno Bipolar/diagnóstico , Psicometria
4.
Artigo em Inglês | MEDLINE | ID: mdl-34051395

RESUMO

BACKGROUND: The spatial functional chronnectome is an innovative mathematical model designed to capture dynamic features in the organization of brain function derived from resting-state functional magnetic resonance imaging data. Measurements of dynamic functional connectivity have been developed from this model to quantify the brain dynamical self-reconfigurations at different spatial and temporal scales. This study examined whether two spatiotemporal dynamic functional connectivity quantifications were linked to late adolescence-onset major depressive disorder (AO-MDD), and scaled with depression and symptom severity measured with the Montgomery-Åsberg Depression Rating Scale. METHODS: Thirty-five patients with AO-MDD (21 ± 6 years of age) and 53 age- and sex-matched healthy young participants (20 ± 3 years of age) underwent 3T magnetic resonance imaging structural and resting-state functional magnetic resonance imaging acquisitions. The chronnectome here comprised seven individualized functional networks portrayed along 132 temporal overlapping windows, each framing 110 seconds of resting brain activity. RESULTS: Based on voxelwise analyses, patients with AO-MDD demonstrated significantly reduced temporal variability within the bilateral prefrontal cortex in five functional networks including the limbic network, default mode network, and frontoparietal network. Furthermore, the limbic network appeared to be particularly involved in this sample and was associated with Montgomery-Åsberg Depression Rating Scale scores, and its progressive dynamic inflexibility was linked to sadness. Default mode network and frontoparietal network dynamics scaled with negative thoughts and neurovegetative symptoms, respectively. CONCLUSIONS: This triple-network imbalance could delay spatiotemporal integration, while across-subject symptom variability would be network specific. Therefore, the present approach supports that brain network dynamics underlie patients' symptom heterogeneity in AO-MDD.


Assuntos
Transtorno Depressivo Maior , Adolescente , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Depressão , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade
5.
Brain Stimul ; 15(1): 201-210, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34954085

RESUMO

BACKGROUND: A comprehensive understanding of variations in the use of electroconvulsive therapy (ECT) among health care providers in charge of ECT referrals is lacking. OBJECTIVE: Our objectives were to document ECT use and its variations on a nationwide scale in France and to identify the factors that were significantly associated with these variations. METHODS: Administrative health claims data on hospitalization were used to perform a descriptive analysis of ECT use for adult patients receiving inpatient psychiatric care in mainland France in 2019 and its variations across hospitals in charge of ECT referrals. Based on a conceptual framework drawn from the literature on medical practice variations, a multilevel logistic regression was then conducted to identify patients, hospitals and contextual characteristics that were significantly associated with ECT treatment using non-ECT-treated patients receiving inpatient psychiatric care as the reference population. RESULTS: Patients receiving ECT (n = 3288) were older, more frequently female and had more severe diagnoses than other patients seen in inpatient care (n = 295,678). Significant variations were observed in the rate of ECT use across hospitals (n = 468), with a coefficient of variation largely above one. In the multivariable analysis, ECT treatment was associated with patient characteristics (which accounted for 6% of the variations) but also with characteristics of the hospitals and their environments (44% of the variations), including the type of hospital and its distance to the closest facility providing ECT. CONCLUSIONS: Variations in ECT use were strongly linked to health care supply characteristics, which raises questions about access to quality mental health care.


Assuntos
Eletroconvulsoterapia , Adulto , Atenção à Saúde , Feminino , França , Hospitalização , Humanos , Pacientes Internados
6.
Eur Neuropsychopharmacol ; 49: 11-22, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33770525

RESUMO

Early initiation of polysubstance use (PSU) is a strong predictor of subsequent addiction, however scarce individuals present resilience capacity. This neuroimaging study aimed to investigate structural correlates associated with cessation or reduction of PSU and determine the extent to which brain structural features accounted for this resilient outcome. Participants from a European community-based cohort self-reported their alcohol, tobacco and cannabis use frequency at ages 14, 16 and 19 and had neuroimaging sessions at ages 14 and 19. We included three groups in the study: the resilient-to-PSU participants showed PSU at 16 and/or 14 but no more at 19 (n = 18), the enduring polysubstance users at 19 displayed PSU continuation from 14 or 16 (n = 193) and the controls were abstinent or low drinking participants (n = 460). We conducted between-group comparisons of grey matter volumes on whole brain using voxel-based morphometry and regional fractional anisotropy using tract-based spatial statistics. Random-forests machine-learning approach generated individual-level PSU-behavior predictions based on personality and neuroimaging features. Adolescents resilient to PSU showed significant larger grey matter volumes in the bilateral cingulate gyrus compared with enduring polysubstance users and controls at ages 19 and 14 (p<0.05 corrected) but no difference in fractional anisotropy. The larger cingulate volumes and personality trait "openness to experience" were the best precursors of resilience to PSU. Early in adolescence, a larger cingulate gyrus differentiated adolescents resilient to PSU, and this feature was critical in predicting this outcome. This study encourages further research into the neurobiological bases of resilience to addictive behaviors.


Assuntos
Alcoolismo , Transtornos Relacionados ao Uso de Substâncias , Adolescente , Adulto , Encéfalo/diagnóstico por imagem , Seguimentos , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Transtornos Relacionados ao Uso de Substâncias/diagnóstico por imagem , Adulto Jovem
7.
J Affect Disord ; 262: 273-277, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31732277

RESUMO

BACKGROUND: A reduced presynaptic dopamine neurotransmission has long been implicated in major depressive disorder (MDD). However, molecular imaging studies that assessed the dopamine transporter (DAT) availability have led to inconsistent results, partly due to methodological considerations, and to exclusive focus on the striatum, precluding findings in extra-striatal regions. METHODS: Herein, we leveraged our database of high-resolution Positron Emission Tomography (PET) images acquired with a highly selective radiotracer, [11C]PE2I, to assess striatal and extra-striatal DAT availability in eight patients treated for depression compared to twenty-four healthy controls. RESULTS: Statistical parametric mapping and voxel-based analyses of PET images detected a significant lower DAT availability in depressed patients within the superior part of the midbrain (right, pFWE = 0.002; left, pFWE = 0.006), a region including the ventral tegmental area and the substantia nigra from where the mesocorticolimbic and nigrostriatal dopamine pathways originate. A similar difference was found in the right dorsal putamen (pFWE = 0.012). LIMITATIONS: The statistical power was limited to detect only large effects, due to the size of the patients' sample. CONCLUSIONS: The findings support the hypothesis that a reduced presynaptic dopamine function plays a role in the pathophysiology of depression, and that extra-striatal dopamine function should be further investigated.


Assuntos
Transtorno Depressivo Maior/diagnóstico por imagem , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Mesencéfalo/diagnóstico por imagem , Imagem Molecular/métodos , Tomografia por Emissão de Pósitrons/métodos , Adulto , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/metabolismo , Transtorno Depressivo Maior/metabolismo , Feminino , Humanos , Masculino , Mesencéfalo/metabolismo , Pessoa de Meia-Idade , Putamen/diagnóstico por imagem , Putamen/metabolismo , Substância Negra/diagnóstico por imagem , Substância Negra/metabolismo
8.
Psychiatry Res ; 284: 112662, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31703985

RESUMO

AIMS: To compare prevalence and risk factors for burnout, anxiety and depression among hospital psychiatrists and non-psychiatrists. METHOD: Regional online survey of psychiatric and non-psychiatric hospital physicians was performed including: a job-stress scale, the Hospital Anxiety and Depression Scale (HADS), the Copenhagen Burnout Inventory (CBI), a stressful work relationships list and a six items scale about work-related psychosocial risk factors (PRFs). The client-related burnout scale of the CBI has been changed to an interpersonal burnout scale. Cases were defined by a score of 8+ for the HADS-A/HADS-D and 50+ for the three CBI subscales. RESULTS: 285 psychiatrists and 326 non-psychiatrists participated. The prevalence of depression, personal burnout and work-related burnout did not differ between physicians. Anxiety was lower in psychiatrists and interpersonal burnout was higher in senior psychiatrists. Multivariate analysis showed two main PRFs, common to both groups of physicians: "work intensity and time" was associated with four of the five syndromes and "emotional demands" with the three burnout syndromes. Interpersonal burnout was associated with stressful relationships with leaders, but not with patients. CONCLUSION: Reducing the workload, improving the management of emotions and increasing managerial skills are important approaches for prevention.


Assuntos
Esgotamento Profissional/psicologia , Transtorno Depressivo/psicologia , Hospitais Psiquiátricos , Estresse Ocupacional/psicologia , Médicos/psicologia , Psiquiatria , Adulto , Esgotamento Profissional/diagnóstico , Esgotamento Profissional/terapia , Estudos Transversais , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/terapia , Feminino , Hospitais Psiquiátricos/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Ocupacional/diagnóstico , Estresse Ocupacional/terapia , Médicos/tendências , Psiquiatria/tendências , Fatores de Risco , Autorrelato , Carga de Trabalho/psicologia
9.
Neuropsychopharmacology ; 43(4): 820-827, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28829051

RESUMO

Dopamine function and reward processing are highly interrelated and involve common brain regions afferent to the nucleus accumbens, within the mesolimbic pathway. Although dopamine function and reward system neural activity are impaired in most psychiatric disorders, it is unknown whether alterations in the dopamine system underlie variations in reward processing across a continuum encompassing health and these disorders. We explored the relationship between dopamine function and neural activity during reward anticipation in 27 participants including healthy volunteers and psychiatric patients with schizophrenia, depression, or cocaine addiction, using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) multimodal imaging with a voxel-based statistical approach. Dopamine transporter (DAT) availability was assessed with PET and [11C]PE2I as a marker of presynaptic dopamine function, and reward-related neural response was assessed using fMRI with a modified Monetary Incentive Delay task. Across all the participants, DAT availability in the midbrain correlated positively with the neural response to anticipation of reward in the nucleus accumbens. Moreover, this relationship was conserved in each clinical subgroup, despite the heterogeneity of mental illnesses examined. For the first time, a direct link between DAT availability and reward anticipation was detected within the mesolimbic pathway in healthy and psychiatric participants, and suggests that dopaminergic dysfunction is a common mechanism underlying the alterations of reward processing observed in patients across diagnostic categories. The findings support the use of a dimensional approach in psychiatry, as promoted by the Research Domain Criteria project to identify neurobiological signatures of core dysfunctions underling mental illnesses.


Assuntos
Antecipação Psicológica/fisiologia , Encéfalo/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Recompensa , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Masculino , Imagem Multimodal/métodos , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/metabolismo , Estimulação Luminosa/métodos , Desempenho Psicomotor/fisiologia
10.
Schizophr Bull ; 43(5): 1134-1142, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28177089

RESUMO

Neuroimaging studies investigating dopamine (DA) function widely support the hypothesis of presynaptic striatal DA hyperactivity in schizophrenia. However, published data on the striatal DA transporter (DAT) appear less consistent with this hypothesis, probably partly due to methodological limitations. Moreover, DAT in extrastriatal regions has been very poorly investigated in the context of schizophrenia. In order to address these issues, we used a high resolution positron emission tomograph and the selective DAT radioligand [11C]PE2I, coupled with a whole brain voxel-based analysis method to investigate DAT availability in striatal but also extra-striatal regions in 21 male chronic schizophrenia patients compared to 30 healthy male controls matched by age. We found higher DAT availability in schizophrenia patients in midbrain, striatal, and limbic regions. DAT availability in amygdala/hippocampus and putamen/pallidum was positively correlated with hallucinations and suspiciousness/persecution, respectively. These results are consistent with an increase of presynaptic DA function in patients with schizophrenia, and support the involvement of both striatal and extrastriatal DA dysfunction in positive psychotic symptoms. The study also highlights the whole brain voxel-based analysis method to explore DA dysfunction in schizophrenia.


Assuntos
Corpo Estriado/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Sistema Límbico/metabolismo , Mesencéfalo/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Esquizofrenia/metabolismo , Esquizofrenia/fisiopatologia , Adulto , Corpo Estriado/diagnóstico por imagem , Humanos , Sistema Límbico/diagnóstico por imagem , Masculino , Mesencéfalo/diagnóstico por imagem , Esquizofrenia/diagnóstico por imagem , Adulto Jovem
11.
Neuropsychopharmacology ; 41(9): 2294-302, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26892922

RESUMO

Modafinil is a candidate compound for the treatment of cocaine addiction that binds to the dopamine transporter (DAT) in healthy humans, as observed by positron emission tomography (PET). This mechanism, analogous to that of cocaine, might mediate a putative therapeutic effect of modafinil on cocaine dependence, though the binding of modafinil to DAT has never been assessed in cocaine-dependent patients. We aimed at quantifying the DAT availability during a controlled treatment by modafinil, and its clinical and psychometric correlates in cocaine-dependent patients at the onset of abstinence initiation. Twenty-nine cocaine-dependent male patients were enrolled in a 3-month trial for cocaine abstinence. Modafinil was used in a randomized double-blind placebo-controlled design and was administered as follows: 400 mg/day for 26 days, then 300 mg/day for 30 days, and 200 mg/day for 31 days. Participants were examined twice during a 17-day hospitalization for their DAT availability using PET and [(11)C]-PE2I and for assessments of craving, depressive symptoms, working memory, and decision-making. Cocaine abstinence was further assessed during a 10-week outpatient follow-up period. Baseline [(11)C]-PE2I-binding potential covaried with risk taking and craving index in striatal and extrastriatal regions. A 65.6% decrease of binding potential was detected in patients receiving modafinil for 2 weeks, whereas placebo induced no significant change. During hospitalization, an equivalent improvement in clinical outcomes was observed in both treatment groups, and during the outpatient follow-up there were more therapeutic failures in the modafinil-treated group. Therefore, these results do not support the usefulness of modafinil to treat cocaine addiction.


Assuntos
Compostos Benzidrílicos/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Transtornos Relacionados ao Uso de Cocaína/prevenção & controle , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Adulto , Compostos Benzidrílicos/administração & dosagem , Encéfalo/diagnóstico por imagem , Fissura/efeitos dos fármacos , Tomada de Decisões/efeitos dos fármacos , Depressão , Método Duplo-Cego , Humanos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Pessoa de Meia-Idade , Modafinila , Nortropanos , Tomografia por Emissão de Pósitrons
12.
Nucl Med Commun ; 35(12): 1254-61, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25185897

RESUMO

INTRODUCTION: [C]Befloxatone is a highly specific, reversible, and selective radioligand for brain PET imaging of monoamine oxidase-A and can be quantified by a two-tissue compartment model (2TCM) and an arterial input function. The aims of the present study were the following: (a) to assess whether in-vivo protein concentration, as measured by [C]befloxatone total distribution volume (VT), is correlated with post-mortem mRNA expression; (b) to replicate in a population of tobacco smokers the results of a recent study on healthy nonsmokers, which showed that spectral analysis (SA) provides a highly accurate estimation of [C]befloxatone-VT at the voxel level; and (c) to validate the use of an input function that would not require arterial sampling. MATERIALS AND METHODS: Healthy male nonsmokers (n=7) and smokers (n=8) were imaged with PET and [C]befloxatone. Binding was quantified at the regional and voxel level with the Logan plot, multilinear analysis (MA1), and SA. VT values were compared with the reference values obtained by 2TCM at the regional level. [C]Befloxatone binding was compared with mRNA transcription maps from the Allen Human Brain Atlas. A less-invasive input function was obtained with a population-based input function (PBIF) scaled with arterialized venous samples. RESULTS: mRNA expression was highly correlated with in-vivo 2TCM-VT values both for nonsmokers (R=0.873; P<0.0001) and for smokers (R=0.851; P<0.0001). At the regional level, both Logan and MA1 showed a moderate negative bias (-5 to -10%) compared with the reference VT values. With the exception of a single outlying individual, SA showed little bias and variability (+4.4±3.5%). Although variability was higher than at the regional level, SA provided the most accurate VT estimations at the voxel level: all but one participant had an error of less than 20%. Parametric Logan and MA1 analyses gave highly biased or unusable results. PBIF provided good results in all participants in whom the arterialization of venous blood was successful (all errors of about 10% or less). CONCLUSION: [C]Befloxatone binding is strongly correlated with the values of mRNA transcription measured in post-mortem brains. At the voxel level, SA is the best available choice for [C]befloxatone quantification, although a higher variability must be expected. When an arterial input function is not technically feasible, a PBIF scaled with arterialized venous samples may provide an acceptable alternative, provided an optimal arterialization can be achieved.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/enzimologia , Monoaminoxidase/genética , Monoaminoxidase/metabolismo , Oxazóis , Tomografia por Emissão de Pósitrons , Transcrição Gênica , Adulto , Radioisótopos de Carbono , Regulação Enzimológica da Expressão Gênica , Humanos , Masculino , Oxazóis/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
13.
EJNMMI Res ; 3(1): 78, 2013 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-24274579

RESUMO

BACKGROUND: [11C]Befloxatone measures the density of the enzyme monoamine oxidase A (MAO-A) in the brain. MAO-A is responsible for the degradation of different neurotransmitters and is implicated in several neurologic and psychiatric illnesses. This study sought to estimate the distribution volume (VT) values of [11C]befloxatone in humans using an arterial input function. METHODS: Seven healthy volunteers were imaged with positron emission tomography (PET) after [11C]befloxatone injection. Kinetic analysis was performed using an arterial input function in association with compartmental modeling and with the Logan plot, multilinear analysis (MA1), and standard spectral analysis (SA) at both the regional and voxel level. Arterialized venous samples were drawn as an alternative and less invasive input function. RESULTS: An unconstrained two-compartment model reliably quantified VT values in large brain regions. A constrained model did not significantly improve VT identifiability. Similar VT results were obtained using SA; however, the Logan plot and MA1 slightly underestimated VT values (about -10%). At the voxel level, SA showed a very small bias (+2%) compared to compartmental modeling, Logan severely underestimated VT values, and voxel-wise images obtained with MA1 were too noisy to be reliably quantified. Arterialized venous blood samples did not provide a satisfactory alternative input function as the Logan-VT regional values were not comparable to those obtained with arterial sampling in all subjects. CONCLUSIONS: Binding of [11C]befloxatone to MAO-A can be quantified using an arterial input function and a two-compartment model or, in parametric images, with SA.

14.
Addict Biol ; 17(6): 981-90, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21812871

RESUMO

The dopamine (DA) system is known to be involved in the reward and dependence mechanisms of addiction. However, modifications in dopaminergic neurotransmission associated with long-term tobacco and cannabis use have been poorly documented in vivo. In order to assess striatal and extrastriatal dopamine transporter (DAT) availability in tobacco and cannabis addiction, three groups of male age-matched subjects were compared: 11 healthy non-smoker subjects, 14 tobacco-dependent smokers (17.6 ± 5.3 cigarettes/day for 12.1 ± 8.5 years) and 13 cannabis and tobacco smokers (CTS) (4.8 ± 5.3 cannabis joints/day for 8.7 ± 3.9 years). DAT availability was examined in positron emission tomography (HRRT) with a high resolution research tomograph after injection of [11C]PE2I, a selective DAT radioligand. Region of interest and voxel-by-voxel approaches using a simplified reference tissue model were performed for the between-group comparison of DAT availability. Measurements in the dorsal striatum from both analyses were concordant and showed a mean 20% lower DAT availability in drug users compared with controls. Whole-brain analysis also revealed lower DAT availability in the ventral striatum, the midbrain, the middle cingulate and the thalamus (ranging from -15 to -30%). The DAT availability was slightly lower in all regions in CTS than in subjects who smoke tobacco only, but the difference does not reach a significant level. These results support the existence of a decrease in DAT availability associated with tobacco and cannabis addictions involving all dopaminergic brain circuits. These findings are consistent with the idea of a global decrease in cerebral DA activity in dependent subjects.


Assuntos
Encéfalo/metabolismo , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Abuso de Maconha/metabolismo , Tabagismo/metabolismo , Adulto , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/metabolismo , Encéfalo/diagnóstico por imagem , Estudos de Casos e Controles , Núcleo Caudado/diagnóstico por imagem , Núcleo Caudado/metabolismo , Humanos , Masculino , Abuso de Maconha/diagnóstico por imagem , Nortropanos , Tomografia por Emissão de Pósitrons , Putamen/diagnóstico por imagem , Putamen/metabolismo , Compostos Radiofarmacêuticos , Substância Negra/diagnóstico por imagem , Substância Negra/metabolismo , Núcleos Talâmicos/diagnóstico por imagem , Núcleos Talâmicos/metabolismo , Tabagismo/diagnóstico por imagem
15.
Addict Biol ; 14(4): 469-77, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19650816

RESUMO

Smoking cues (SCs) refer to smoking-associated environmental stimuli that may trigger craving and withdrawal symptoms, and predispose to relapse in smokers. Although previous brain imaging studies have explored neural responses to SCs, no study has characterized the effects of SCs on cerebral activity in smokers engaged in an attention-demanding cognitive task that is unrelated to smoking. Thirteen tobacco smokers and a demographically matched group of 13 healthy non-smokers participated in a fast event-related functional magnetic resonance imaging (fMRI) study that involved a visual task integrating SCs and neutral cues (NCs) during emotion recognition trials requiring a high level of attention. No significant SC-induced alterations were detected in smokers' behavioural performance. fMRI results show that non-smokers exhibited no difference between SC and NC trials; in contrast, smokers showed SC-induced widespread deactivations in a limbic, paralimbic and striatal network classically involved in addiction, and activation in the right dorsolateral prefrontal cortex. In addition, a correlation between deactivation of the right insula and the severity of smoking dependence (Fagerström test) was detected in smokers. These results suggest that the neural reactivity of smokers to SCs can be modified in the context of a cognitive challenge. This could reflect smokers' ability to inhibit cue-induced craving and may help in smoking cessation.


Assuntos
Afeto , Sistema Límbico/metabolismo , Sistema Límbico/fisiopatologia , Imageamento por Ressonância Magnética , Reconhecimento Psicológico , Fumar , Tabagismo/metabolismo , Tabagismo/fisiopatologia , Adulto , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Sinais (Psicologia) , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Estimulação Luminosa , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/fisiopatologia , Abandono do Hábito de Fumar/métodos , Prevenção do Hábito de Fumar , Adulto Jovem
16.
J Clin Psychopharmacol ; 29(1): 86-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19142115

RESUMO

The inhibition of cerebral monoamine oxidases (MAOs) by cigarette smoke components could participate to the tobacco addiction. However, the actual extent of this inhibition in vivo in smokers is still poorly known. We investigated cerebral MAO-A availability in 7 tobacco-dependent subjects and 6 healthy nonsmokers, using positron emission tomography (PET) and the MAO-A selective radioligand [C]befloxatone. In comparison to nonsmokers, smokers showed a significant overall reduction of [C]befloxatone binding potential (BP) in cortical areas (average reduction, -60%) and a similar trend in caudate and thalamus (-40%). Our findings confirm a widespread inhibition of cerebral MAO-A in smokers. This mechanism may contribute to tobacco addiction and for a possible mood-modulating effect of tobacco.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/enzimologia , Inibidores da Monoaminoxidase/farmacologia , Monoaminoxidase/metabolismo , Oxazóis/farmacocinética , Compostos Radiofarmacêuticos/farmacocinética , Adulto , Radioisótopos de Carbono , Humanos , Masculino , Inibidores da Monoaminoxidase/metabolismo , Nicotina/administração & dosagem , Nicotina/farmacologia , Agonistas Nicotínicos/administração & dosagem , Agonistas Nicotínicos/farmacologia , Tomografia por Emissão de Pósitrons , Fumar/fisiopatologia , Distribuição Tecidual
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