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1.
Nat Commun ; 15(1): 248, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38172100

RESUMO

Suggestions about hunger can generate placebo effects on hunger experiences. But, the underlying neurocognitive mechanisms are unknown. Here, we show in 255 women that hunger expectancies, induced by suggestion-based placebo interventions, determine hunger sensations and economic food choices. Functional magnetic resonance imaging in a subgroup (n = 57/255) provides evidence that the strength of expecting the placebo to decrease hunger moderates medial prefrontal cortex activation at the time of food choice and attenuates ventromedial prefrontal cortex (vmPFC) responses to food value. Dorsolateral prefrontal cortex activation linked to interference resolution formally mediates the suggestion-based placebo effects on hunger. A drift-diffusion model characterizes this effect by showing that the hunger suggestions bias participants' food choices and how much they weigh tastiness against the healthiness of food, which further moderates vmPFC-dlPFC psychophysiological interactions when participants expect decreased hunger. Thus, suggestion-induced beliefs about hunger shape hunger addressing economic choices through cognitive regulation of value computation within the prefrontal cortex.


Assuntos
Encéfalo , Efeito Placebo , Humanos , Feminino , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiologia , Mapeamento Encefálico/métodos , Preferências Alimentares/fisiologia , Imageamento por Ressonância Magnética/métodos
2.
Brain Struct Funct ; 229(1): 15-29, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37819410

RESUMO

A growing number of evidence supports a continued distribution of autistic traits in the general population. However, brain maturation trajectories of autistic traits as well as the influence of sex on these trajectories remain largely unknown. We investigated the association of autistic traits in the general population, with longitudinal gray matter (GM) maturation trajectories during the critical period of adolescence. We assessed 709 community-based adolescents (54.7% women) at age 14 and 22. After testing the effect of sex, we used whole-brain voxel-based morphometry to measure longitudinal GM volumes changes associated with autistic traits measured by the Social Responsiveness Scale (SRS) total and sub-scores. In women, we observed that the SRS was associated with slower GM volume decrease globally and in the left parahippocampus and middle temporal gyrus. The social communication sub-score correlated with slower GM volume decrease in the left parahippocampal, superior temporal gyrus, and pallidum; and the social cognition sub-score correlated with slower GM volume decrease in the left middle temporal gyrus, the right ventromedial prefrontal and orbitofrontal cortex. No longitudinal association was found in men. Autistic traits in young women were found to be associated with specific brain trajectories in regions of the social brain and the reward circuit known to be involved in Autism Spectrum Disorder. These findings support both the hypothesis of an earlier GM maturation associated with autistic traits in adolescence and of protective mechanisms in women. They advocate for further studies on brain trajectories associated with autistic traits in women.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Masculino , Humanos , Adolescente , Feminino , Adulto , Adulto Jovem , Substância Cinzenta/diagnóstico por imagem , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem
3.
Biol Aujourdhui ; 217(3-4): 151-154, 2023.
Artigo em Francês | MEDLINE | ID: mdl-38018942

RESUMO

Thirty percent of depressed patients are treatment resistant (TRD) suggesting the need of new therapeutic strategy. Recently, it has been shown that ketamine, an anesthetic agent with dissociative effects, has potent and rapid antidepressant properties. Ketamine is a ionotropic glutamatergic NMDA antagonist that inhibits gabaergic neurons. Its antidepressant effect peaks at 24 h post-treatment. Several meta-analyses of placebo randomized clinical trials emphasized its efficacy. More recently, a meta-analysis showed its efficiency in real-world population of TRD patients. Although there is no clear biological or clinical predictors of response or remission to ketamine, patients with high level of resistance were found to remit less often. Restoring both the optimism bias and the asymmetry in belief updating mediates the antidepressant ketamine's effect. Consistent with predictive bayesian model and terror management theory, this suggests that dissociation induced by ketamine may contribute to its clinical antidepressant action. Although increasing access to ketamine and esketamine is welcome, legitimate concerns have been raised with respect to long-term safety and abuse risk.


Title: Évolution ou révolution dans le traitement des dépressions avec la kétamine ? Abstract: Définie par l'échec d'au moins deux antidépresseurs de mécanismes d'action différents, la dépression résistante est fréquente et concerne 30 % des patients déprimés. Elle justifie le recours à des stratégies thérapeutiques innovantes. Depuis quelques années, on utilise un agent anesthésiant et dissociatif, la kétamine, et ses dérivés, dans le traitement de la dépression résistante. Dans cette brève revue de la littérature, nous rapportons les données attestant de l'efficacité et de l'efficience de la kétamine dans cette indication. Certains patients bénéficient plus que d'autres de la kétamine qui est recommandée pour un niveau modéré de résistance. Même si cela reste débattu, la dissociation pourrait contribuer aux effets bénéfiques de la kétamine.


Assuntos
Ketamina , Humanos , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Teorema de Bayes , Ketamina/farmacologia , Ketamina/uso terapêutico , Metanálise como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Neurosci Biobehav Rev ; 154: 105410, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37793581

RESUMO

For the past decade, ketamine, an N-methyl-D-aspartate receptor (NMDAr) antagonist, has been considered a promising treatment for major depressive disorder (MDD). Unlike the delayed effect of monoaminergic treatment, ketamine may produce fast-acting antidepressant effects hours after a single administration at subanesthetic dose. Along with these antidepressant effects, it may also induce transient dissociative (disturbing of the sense of self and reality) symptoms during acute administration which resolve within hours. To understand ketamine's rapid-acting antidepressant effect, several biological hypotheses have been explored, but despite these promising avenues, there is a lack of model to understand the timeframe of antidepressant and dissociative effects of ketamine. In this article, we propose a neurocomputational account of ketamine's antidepressant and dissociative effects based on the Predictive Processing (PP) theory, a framework for cognitive and sensory processing. PP theory suggests that the brain produces top-down predictions to process incoming sensory signals, and generates bottom-up prediction errors (PEs) which are then used to update predictions. This iterative dynamic neural process would relies on N-methyl-D-aspartate (NMDAr) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic receptors (AMPAr), two major component of the glutamatergic signaling. Furthermore, it has been suggested that MDD is characterized by over-rigid predictions which cannot be updated by the PEs, leading to miscalibration of hierarchical inference and self-reinforcing negative feedback loops. Based on former empirical studies using behavioral paradigms, neurophysiological recordings, and computational modeling, we suggest that ketamine impairs top-down predictions by blocking NMDA receptors, and enhances presynaptic glutamate release and PEs, producing transient dissociative symptoms and fast-acting antidepressant effect in hours following acute administration. Moreover, we present data showing that ketamine may enhance a delayed neural plasticity pathways through AMPAr potentiation, triggering a prolonged antidepressant effect up to seven days for unique administration. Taken together, the two sides of antidepressant effects with distinct timeframe could constitute the keystone of antidepressant properties of ketamine. These PP disturbances may also participate to a ketamine-induced time window of mental flexibility, which can be used to improve the psychotherapeutic process. Finally, these proposals could be used as a theoretical framework for future research into fast-acting antidepressants, and combination with existing antidepressant and psychotherapy.


Assuntos
Transtorno Depressivo Maior , Ketamina , Humanos , Ketamina/farmacologia , Transtorno Depressivo Maior/tratamento farmacológico , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Encéfalo/metabolismo , Transdução de Sinais , Receptores de N-Metil-D-Aspartato/metabolismo
5.
Biol Aujourdhui ; 217(1-2): 49-53, 2023.
Artigo em Francês | MEDLINE | ID: mdl-37409864

RESUMO

Usually, trauma is defined as exposure to an event that threatens death or induces serious injury or sexual violence. Beyond post-traumatic stress disorder (PTSD), trauma may increase the risk for severe mental disorders including mood disorders and psychotic disorder. PTSD, following exposure to a traumatic event, is strongly linked to dissociation. However, in contrast convergent findings indicated that, despite the relationship between peri-traumatic dissociation and later PTSD, many people who develop PTSD do not display dissociative responses in the acute phase after the event. Several risk factors are described for PTSD including previous history of traumatic event, previous mental disorders, genetic factors and gender. It is now proposed to distinguish PTSD with or without dissociative symptoms with some specific neural signature for each syndrome. Dissociation may also lead to change in cultural belief and worldview. According to the terror management theory (TMT), it is suggested that cultural worldviews, self-esteem, and interpersonal relationships work together to protect individuals from death anxiety. The trauma, by disrupting this anxiety buffering system, contributes to change beliefs in victims and exposes them to a feeling of social exclusion.


Title: Le concept de traumatisme et ses conséquences théoriques et cliniques. Abstract: Le traumatisme, conçu comme un choc violent, imprévu et qui expose l'individu à sa propre mort, est pourvoyeur de nombreuses pathologies. Dans ce travail, nous discutons principalement le trouble de stress post-traumatique (TSPT), ses spécificités cliniques en fonction du type de traumatisme ainsi que son rapport étroit avec la notion de dissociation. Le traumatisme, par sa violence, bouleverse totalement les croyances fondamentales de l'individu sur les autres, le monde et son rapport à la mort.


Assuntos
Transtornos Psicóticos , Transtornos de Estresse Pós-Traumáticos , Humanos , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/etiologia , Fatores de Risco
7.
Sleep ; 46(2)2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36445852

RESUMO

Dream's emotions could exert a major role in desensitizing negative emotions. Studying emotional dynamics (how emotions fluctuate across time) during rapid eye movement (REM) sleep could provide some insight into this function. However, studies so far have been limited to dream reports. To bypass this limit, REM sleep behavior disorder (RBD), in which participants enact their dreams, enables direct access to overt emotional dream behaviors (such as facial expressions and speeches). In total, 17 participants with RBD, and 39.7 h of REM sleep video were analyzed. The frequency of emotional behaviors did not differ between REM sleep episodes of early and late night. Within individual REM sleep episodes, emotional behaviors exhibited a biphasic temporal course, including an increased frequency for the first 10 min, followed by a progressive decrease. The negative emotional behaviors occurred earlier (mean time: 11.3 ± 10 min) than positive (14.4 ± 10.7 min) and neutral behaviors (16.4 ± 11.8 min). Emotional behaviors of opposing (negative and positive) valences were observed in 31% (N = 14) of episodes containing at least one emotional behavior, and were separated by a median time of 4.2 [1.1-10.9] min. The biphasic temporal course of behaviors in REM sleep could include the generation reactivation of emotional content during the ascending phase, followed by processing and extinction during the descending phase. The earlier occurrence time of negative emotional behavior suggests that negative emotions may need to be processed first. The rapid succession of emotions of opposite valence could prevent prolonged periods of negative emotions and eventually nightmares.


Assuntos
Transtorno do Comportamento do Sono REM , Sono REM , Humanos , Sono REM/fisiologia , Emoções/fisiologia , Sonhos/fisiologia , Polissonografia
8.
Encephale ; 49(1): 103-106, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35973849

RESUMO

At a time when innovations in psychiatry are booming, particularly in the field of medical devices, we thought it necessary, as members of French Society for Biological Psychiatry and Neuropsychopharmacology (AFPBN), to reconsider one of the oldest medical devices in psychiatry: the ECT apparatus. First, we recall the regulatory aspects of ECT. National guidelines define means of implementation and conditions of administration of ECT. Second, we remind of the indications and levels of evidence of ECT in the main psychiatric disorders, including catatonia. Then, we synthetize the place of ECT alongside other brain stimulation therapies, especially repetitive Trancranial Magnetic Stimulation (rTMS). Furthermore, we explain the general effects of ECT: increased neuronal plasticity and neurogenesis, enhancement of the stress axis, resistance to oxidative stress, improved vascular endothelial function, activation of microglia and astrocytes, decrease in inflammatory events by upregulation of neuroinflammatory cytokines, and production of mitochondrial ATP. These effects appear from the first sessions and continue during the course of ECT treatment, suggesting activation of endogenous neuroprotection. Finally, we remember that most patients perform as well or better on neuropsychological assessments after ECT, relative to pre-ECT results, and this improvement continues over the following months. Memory disorders reported post-ECT are not all attributable to ECT. They may be subjective in nature or linked to residual depressive (and possibly comorbid neurogenerative) symptoms later attributed to ECT, on the basis of preexisting negative representations. We urgently need to reemphasize the crucial role of ECT in psychiatric treatment strategies as well as the need to update ECT recommendations.


Assuntos
Catatonia , Eletroconvulsoterapia , Transtornos Mentais , Psiquiatria , Humanos , Eletroconvulsoterapia/métodos , Transtornos Mentais/terapia , Estimulação Magnética Transcraniana/métodos , Catatonia/terapia
9.
J Clin Psychiatry ; 84(1)2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36479951

RESUMO

Objective: To identify factors associated with posttraumatic stress symptoms (PTSS) 3 and 6 months after the discharge of patients hospitalized for COVID-19.Methods: Patients hospitalized for COVID-19 between March 1 and July 31, 2020, were included in a longitudinal study. Clinical assessments were conducted with online auto-questionnaires. PTSS were assessed with the Posttraumatic Stress Disorder Checklist Scale (PCLS). We screened for several putative factors associated with PTSS, including socio-demographic status, hospitalization in an intensive care unit, history of psychiatric disorder, the Hospital Anxiety and Depression Scale, the Peritraumatic Dissociative Experiences Questionnaire, and the home-to-hospital distance. Bivariate and multilinear regression analyses were performed to evaluate their association with PTSS.Results: 119 patients were evaluated 3 months after hospital discharge, and a subset of 94 were evaluated 6 months after discharge. The prevalence of PTSS was 31.9% after 3 months and 30.9% after 6 months. Symptoms of anxiety and depression and history of psychiatric disorder were independently associated with PTSS. Additionally, dissociative experiences during hospitalization (ß = 0.35; P < .001) and a longer home-to-hospital distance (ß = 0.07; P = .017) were specifically associated with PTSS 3 and 6 months after discharge, respectively.Conclusions: Patients with COVID-19 showed persistent high scores of PTSS up to 6 months after discharge from the hospital. In this specific pandemic setting, PTSS were associated with high rates of dissociative experiences during hospitalization and a longer home-to-hospital distance due to the saturation of health care facilities. These results can foster early identification and better prevention of PTSS after hospitalization for COVID-19.Trial Registration: ClinicalTrials.gov identifier: NCT04362930.


Assuntos
COVID-19 , Transtornos de Estresse Pós-Traumáticos , Humanos , COVID-19/epidemiologia , Transtornos de Estresse Pós-Traumáticos/diagnóstico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Estudos Longitudinais
10.
JAMA Psychiatry ; 79(11): 1124-1132, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36169969

RESUMO

Importance: Clinical research has shown that persistent negative beliefs maintain depression and that subanesthetic ketamine infusions induce rapid antidepressant responses. Objective: To evaluate whether ketamine alters belief updating and how such cognitive effects are associated with the clinical effects of ketamine. Design, Setting, and Participants: This study used an observational case-control protocol with a mixed-effects design that nested 2 groups by 2 testing time points. Observers were not blinded. Patients with treatment-resistant depression (TRD) and healthy volunteer participants aged 34 to 68 years were included. Patients with TRD were diagnosed with major depressive disorder or bipolar depression, had a Montgomery-Åsberg Depression Rating Scale score greater than 20, a Maudsley Staging Method score greater than 7, and failed to respond to at least 2 prior antidepressant trials. Exclusion criteria were any other psychiatric, neurological, or neurosurgical comorbidities, substance use or addictive disorders, and recreational ketamine consumption. Data were collected from January to February 2019 and from May to December 2019, and data were analyzed from January 2020 to July 2021. Exposures: Patients with TRD were observed 24 hours before single ketamine infusion, 4 hours after the infusion, and 4 hours after the third infusion, which was 1 week after the first infusion. Healthy control participants were observed twice 1 week apart without ketamine exposure. Main Outcomes and Measures: Montgomery-Åsberg Depression Rating Scale score and belief updating after belief updating when patients received good news and bad news measured by a cognitive belief-updating task and mathematically formalized by a computational reinforcement learning model. Results: Of 56 included participants, 29 (52%) were male, and the mean (SEM) age was 52.3 (1.2) years. A total of 26 patients with TRD and 30 control participants were included. A significant group × testing time point × news valence interaction showed that patients with TRD updated their beliefs more after good than bad news following a single ketamine infusion (controlled for age and education: ß = -0.91; 95% CI, -1.58 to -0.24; t216 = -2.67; P = .008) than controls. Computational modeling showed that this effect was associated with asymmetrical learning rates (LRs) after ketamine treatment (good news LRs after ketamine, 0.51 [SEM, 0.04]; bad news LRs after ketamine 0.36 [SEM, 0.03], t25 = 3.8; P < .001) and partially mediated early antidepressant responses (path a*b: ß = -1.00 [SEM, 0.66]; t26 = -1.53; z = -1.98; P = .04). Conclusions and Relevance: These findings provide novel insights into the cognitive mechanisms of the action of ketamine in patients with TRD, with promising perspectives for augmented psychotherapy for individuals with mood disorders.


Assuntos
Transtorno Depressivo Maior , Transtorno Depressivo Resistente a Tratamento , Ketamina , Humanos , Masculino , Feminino , Ketamina/farmacologia , Ketamina/uso terapêutico , Transtorno Depressivo Maior/tratamento farmacológico , Transtorno Depressivo Maior/induzido quimicamente , Depressão , Infusões Intravenosas , Transtorno Depressivo Resistente a Tratamento/tratamento farmacológico , Antidepressivos/farmacologia , Antidepressivos/uso terapêutico , Viés , Resultado do Tratamento
11.
Int J Mol Sci ; 23(16)2022 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-36012234

RESUMO

The exact neurobiological mechanisms of bipolar disorder (BD) remain unknown. However, some neurometabolites could be implicated, including Glutamate (Glu), Glutamine (Gln), Glx, and N-acetylaspartate (NAA). Proton Magnetic Resonance Spectroscopy (1H-MRS) allows one to quantify these metabolites in the human brain. Thus, we conducted a systematic review and meta-analysis of the literature to compare their levels between BD patients and healthy controls (HC). The main inclusion criteria for inclusion were 1H-MRS studies comparing levels of Glu, Gln, Glx, and NAA in the prefrontal cortex (PFC), anterior cingulate cortex (ACC), and hippocampi between patients with BD in clinical remission or a major depressive episode and HC. Thirty-three studies were included. NAA levels were significantly lower in the left white matter PFC (wmPFC) of depressive and remitted BD patients compared to controls and were also significantly higher in the left dorsolateral PFC (dlPFC) of depressive BD patients compared to HC. Gln levels were significantly higher in the ACC of remitted BD patients compared to in HC. The decreased levels of NAA of BD patients may be related to the alterations in neuroplasticity and synaptic plasticity found in BD patients and may explain the deep white matter hyperintensities frequently observed via magnetic resonance imagery.


Assuntos
Transtorno Bipolar , Transtorno Depressivo Maior , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Transtorno Bipolar/diagnóstico por imagem , Transtorno Bipolar/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Espectroscopia de Prótons por Ressonância Magnética/métodos
12.
Encephale ; 48(6): 682-699, 2022 Dec.
Artigo em Francês | MEDLINE | ID: mdl-35987716

RESUMO

What is mood? Despite its crucial place in psychiatric nosography and cognitive science, it is still difficult to delimit its conceptual ground. The distinction between emotion and mood is ambiguous: mood is often presented as an affective state that is more prolonged and less intense than emotion, or as an affective polarity distinguishing high and low mood swinging around a baseline. However, these definitions do not match the clinical reality of mood disorders such as unipolar depression and bipolar disorder, and do not allow us to understand the effect of mood on behaviour, perception and cognition. In this paper, we propose a multidimensional and computational theory of mood inspired by contemporary hypotheses in theoretical neuroscience and philosophy of emotion. After suggesting an operational distinction between emotion and mood, we show how a succession of emotions can cumulatively generate congruent mood over time, making mood an emerging state from emotion. We then present how mood determines mental and behavioral states when interacting with the environment, constituting a dispositional state of emotion, perception, belief, and action. Using this theoretical framework, we propose a computational representation of the emerging and dispositional dimensions of mood by formalizing mood as a layer of third-order Bayesian beliefs encoding the precision of emotion, and regulated by prediction errors associated with interoceptive predictions. Finally, we show how this theoretical framework sheds light on the processes involved in mood disorders, the emergence of mood congruent beliefs, or the mechanisms of antidepressant treatments in clinical psychiatry.


Assuntos
Afeto , Transtorno Bipolar , Humanos , Teorema de Bayes , Emoções , Transtornos do Humor/psicologia , Transtorno Bipolar/psicologia
13.
J Clin Sleep Med ; 18(7): 1847-1855, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35404227

RESUMO

STUDY OBJECTIVES: Posttraumatic nightmares may exacerbate and perpetuate the daytime symptoms of posttraumatic stress disorder and might represent a therapeutic target. The therapeutic strategy of memory reconsolidation using the ß-adrenergic receptor blocker propranolol associated with re-exposure psychotherapy is a promising treatment in patients with posttraumatic stress disorder. Previous studies have established this therapy is effective in reducing overall clinician-assessed posttraumatic stress disorder symptoms, but to date no previous study has specifically focused on posttraumatic nightmares in this therapy. This study provides a preliminary assessment of the evolution of nightmare severity during this therapy protocol compared with the decrease of the other posttraumatic stress disorder symptoms. It evaluates the incidence of side effects and examines the relative effects on posttraumatic nightmares. METHODS: Patients were recruited as part of the Paris Mémoire Vive Study. Data were collected using a prospective longitudinal design including 1 baseline visit, 6 therapeutic visits, and 2 follow-up visits. During the 6 therapeutic visits, propranolol was administered orally 60 to 75 minutes prior to the psychotherapeutic session. RESULTS: On average, nightmare severity decreased from "severe" to "mild" during the protocol and remained stable 2 months after the last session. Whereas 85% of patients reported nightmares at baseline, only 50% still had them after the protocol. The protocol was generally well tolerated and did not increase nightmare severity for any patient in the study. CONCLUSIONS: Memory reconsolidation therapy with propranolol seems promising in reducing nightmare severity, up to and including remission. However, research using a randomized controlled design and assessing maintenance of nightmare extinction is warranted. CLINICAL TRIAL REGISTRATION: Registry: ClinicalTrials.gov; Name: Using Reconsolidation Blockade to Treat Trauma Related Disorders After Paris Attacks: An Effectiveness Study (PARIS-MEM); Identifier: NCT02789982; URL: https://www.clinicaltrials.gov/ct2/show/NCT02789982. CITATION: Mallet C, Chick CF, Maatoug R, Fossati P, Brunet A, Millet B. Memory reconsolidation impairment using the ß-adrenergic receptor blocker propranolol reduces nightmare severity in patients with posttraumatic stress disorder: a preliminary study. J Clin Sleep Med. 2022;18(7):1847-1855.


Assuntos
Sonhos , Transtornos de Estresse Pós-Traumáticos , Antagonistas Adrenérgicos beta/uso terapêutico , Humanos , Transtornos da Memória/complicações , Propranolol/farmacologia , Propranolol/uso terapêutico , Estudos Prospectivos , Receptores Adrenérgicos beta , Transtornos de Estresse Pós-Traumáticos/complicações
14.
Sci Rep ; 11(1): 18489, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34531416

RESUMO

The neuromodulation induced by neurofeedback training (NFT) remains a matter of debate. Investigating the modulation of brain activity specifically associated with NF requires controlling for multiple factors, such as reward, performance, congruency between task and targeted brain activity. This can be achieved using sham feedback (FB) control condition, equating all aspects of the experiment but the link between brain activity and FB. We aimed at investigating the modulation of individual alpha EEG activity induced by NFT in a double-blind, randomized, sham-controlled study. Forty-eight healthy participants were assigned to either NF (n = 25) or control (n = 23) group and performed alpha upregulation training (over 12 weeks) with a wearable EEG device. Participants of the NF group received FB based on their individual alpha activity. The control group received the auditory FB of participants of the NF group. An increase of alpha activity across training sessions was observed in the NF group only (p < 0.001). This neuromodulation was selective in that there was no evidence for similar effects in the theta (4-8 Hz) and low beta (13-18 Hz) bands. While alpha upregulation was found in the NF group only, psychological outcome variables showed overall increased feeling of control, decreased anxiety level and increased relaxation feeling, without any significant difference between the NF and the control groups. This is interpreted in terms of learning context and placebo effects. Our results pave the way to self-learnt, NF-based neuromodulation with light-weighted, wearable EEG systems.


Assuntos
Ritmo alfa , Neurorretroalimentação/métodos , Reforço Psicológico , Adolescente , Adulto , Encéfalo/fisiologia , Humanos , Pessoa de Meia-Idade
15.
J Affect Disord ; 293: 347-354, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229288

RESUMO

Aberrant DMN connectivity and activity have been robustly linked to Major Depressive Disorder (MDD) and risk for depression. This link has mostly been explained in terms of rumination, a form of negative, repetitive cognitive processing. Yet, accumulating findings are indicating altered DMN dynamics during emotional processing in MDD, pointing at a potential emotion-related DMN pathology in depression linked to inflexibly sustained emotional responses. Such a link might be especially important in understanding risk of depression. However, whether inflexible emotional processing (i.e. emotional inertia) is connecting aberrant DMN organization to risk of depression as well as how this might relate to rumination remains unclear. Addressing this gap, 34 participants underwent a resting-state fMRI and a 7-day Experience Sampling phase. Using regression and multiple mediation analysis we investigated the relations between negative emotional inertia, rumination, DMN organization and risk of depression as indicated by high subclinical depressive symptoms. The findings indicated that DMN efficiency at rest was positively associated with depressive symptoms and risk of depression. Both negative emotional inertia in daily life and rumination were independently mediating this relationship. While negative emotional inertia was connected to a broad increase in the coupling of DMN regions, rumination was only related to an increase in node strength of the dorsomedial Prefrontal Cortex. These findings are pointing towards an emotional-related DMN pathology contributing to risk of depression. Furthermore the findings are indicating that this relationship is independent from the rumination-related link between the DMN and depression - representing different aspects of DMN organization.


Assuntos
Depressão , Transtorno Depressivo Maior , Encéfalo , Mapeamento Encefálico , Rede de Modo Padrão , Depressão/diagnóstico por imagem , Transtorno Depressivo Maior/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Vias Neurais
16.
Front Psychiatry ; 11: 544999, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33192659

RESUMO

Changes in mind-wandering (MW) and involuntary autobiographical memory (IAM) in dysphoria have been explored with conflicting results. The aim of this study was to evaluate both MW and IAM in a group of 23 stable dysphoric participants compared to 37 controls and to compare their thoughts characteristics (i.e., specificity, visual perspective, time orientation, and emotional valence). To make this study comparable with previous research, we used two different monotonous vigilance tasks (with and without verbal interference stimuli). Our results showed a significantly greater focus on MW thoughts in dysphoria. The characteristics of spontaneous thoughts content did not differ significantly between our dysphoric participants and controls, which is not in favor of strong emotional dysfunction. Our results suggest a difficulty to regulate the occurrence of self-generated thoughts rather than their content, that may confer to dysphoric subjects increased cognitive risk to develop a major depressive episode.

19.
Front Psychiatry ; 11: 554, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32714212

RESUMO

OBJECTIVES: Obsessive-compulsive disorder usually begins in adolescence or young adulthood. OCD cases appearing after the age of 50 years are rare, most often associated with inflammatory, brain lesions, or neurodegenerative comorbidities. We describe two cases of late-onset obsessive compulsive disorder followed by the development of Dementia with Lewy Bodies and review the links between these two disorders. METHODS AND RESULTS: We describe the clinical history of two patients that first showed OCD symptoms at an atypical age (>60 years). After several failed treatment attempts, they were hospitalized in our unit. Both presented severe sensitivity to antipsychotic agents that led to a diagnosis of Dementia with Lewy Bodies. Administration of cholinesterase inhibitors was associated with decrease of psychiatric symptoms in both cases. In addition to those clinical observations, a systematic review of the literature suggests that, beyond prefrontal cortex, temporal lobe and putamen have important roles in OCD pathophysiology. Based on these findings, we discuss four hypotheses to explain the sequential appearance of OCD and DLB symptoms. First, we considered the possibility that comorbidity of OCD with DLB was coincidental. Second, we propose to interpret OCD symptoms as motor stereotypies. Third, we hypothesize that late-onset OCD might be a symptom of late-onset depression. Four, we hypothesize that through early deterioration of basal ganglia, DLB caused the onset of OCD. CONCLUSION: In conclusion, we recommend that cases of late-onset treatment-resistant OCD should be carefully tested for possible organic etiologies, and for DLB in particular.

20.
Front Psychiatry ; 11: 371, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457663

RESUMO

Burnout rates are estimated to be twice as high among healthcare professionals as in the general working population, and studies indicate rising incidence. The present study aimed to identify the contextual factors associated with self-reported burnout rates among French psychiatrists. A total of 860 French or French-speaking psychiatrists completed an online questionnaire when they registered for a major psychiatric conference. The Copenhagen Burnout Inventory, a validated scale that independently appraises personal, work- and patient-related dimensions, was used to assess the degree of perceived burnout. Respondents were divided into lower risk and higher risk groups. The latter contained the 25% of individuals who scored the highest on each of the three dimensions of the CBI scale. Univariate analysis showed that private practice was associated with lower levels of risk on the personal and work-related dimensions. Working for the public sector and long hours were both associated with a higher score on the work-related dimension. Interestingly, none of the variables we investigated, except from poor atmosphere at work, correlated with the patient-related dimension. Among public-sector psychiatrists, female gender, longer hours, and more consultations per week were associated with a higher score on the work-related dimension. Working four or more night shifts per month was significantly associated with a higher score of burnout risk on all three dimensions. Private- and public-sector practitioners who mainly treated patients with schizophrenia had a higher score of burnout risk. Multivariate analysis showed that a poor atmosphere at work, longer hours, and working four or more night shifts were significantly associated with higher score of burnout risk. A nonreassuring working environment and more stressors while treating patients each had a possibly negative impact. Although this study only examined the factors that distinguish between clinicians with the lowest versus highest CBI burnout risk scores, it opens up important avenues for research and development of programs to reduce burnout risk within the French healthcare system.

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