Phénoménologie des pensées accélérées et grouillantes dans les troubles de l'humeur : une réévaluation théorique

La tachypsychie ou accélération du cours de la pensée est un symptôme fréquent des troubles de l'humeur, en particulier des états dépressifs mixtes (plus de 50% des cas). Ce travail a pour but de résumer notre connaissance actuelle du sujet, et de proposer un modèle théorique. En effet, si dans le cadre d'un état hypomane la tachypsychie peut apparaître comme une production excessive et linéaire de pensées, dans le contexte d'un état dépressif par contre ce symptôme est probablement mieux décrit comme des pensées "grouillantes", comprenant aussi un sentiment de persistance. Le patient se plaint d'avoir trop d'idées en même temps dans son champ de conscience, ce qui induit habituellement une sensation déplaisante. Nous en concluons que deux processus sous-tendent probablement de manière différenciée ces troubles du cours de la pensée: la production de pensées d'une part et la capacité à inhiber les pensées actuelles d'autre part. Cette distinction pourrait aider à mieux comprendre et diagnostiquer les états dépressifs mixtes

Neural correlates of thought disorders in mood disorders

Les patients présentant des troubles de l'humeur ont souvent des troubles de la pensée, et notamment des pensées accélérées, grouillantes ou des ruminations. Nous voulions investiguer des processus cognitifs qui pourraient être à la base de ces symptômes et leurs substrats neuronaux. Nous avons donc comparé un groupe de patients avec troubles de l'humeur (N=32) et un groupe de participants appariés, afin de tester leur flexibilité cognitive/inhibition, et leur mode d'associations verbales. Les résultats montrent qu'en effet les patients ont plus de difficulté à passer d'une tâche à l'autre, ce qui correspond à une activation inefficace de régions du réseau fronto-pariétal. Ils ont aussi de la peine à désactiver le cortex cingulaire subgénual lors de condition d'inhibition. Lors d'une tâche d'association de mots, les patients inhibent difficilement les automatismes (associé à moins d'activité du réseau sémantique), et activent plus des régions liées au self en réponse à des stimuli émotionnels

What makes your brain suggestible? Hypnotizability is associated with differential brain activity during attention outside hypnosis

Theoretical models of hypnosis have emphasized the importance of attentional processes in accounting for hypnotic phenomena but their exact nature and brain substrates remain unresolved. Individuals vary in their susceptibility to hypnosis, a variability often attributed to differences in attentional functioning such as greater ability to filter irrelevant information and inhibit prepotent responses. However, behavioral studies of attentional performance outside the hypnotic state have provided conflicting results. We used fMRI to investigate the recruitment of attentional networks during a modified flanker task in High and Low hypnotizable participants. The task was performed in a normal (no hypnotized) state. While behavioral performance did not reliably differ between groups, components of the fronto-parietal executive network implicated in monitoring (anterior cingulate cortex; ACC), adjustment (lateral prefrontal cortex; latPFC), and implementation of attentional control (intraparietal sulcus; IPS) were differently activated depending on the hypnotizability of the subjects: the right inferior frontal gyrus (rIFG) was more recruited, whereas IPS and ACC were less recruited by High susceptible individuals compared to Low. Our results demonstrate that susceptibility to hypnosis is associated with particular executive control capabilities allowing efficient attentional focusing, and point to specific neural substrates in right prefrontal cortex

The Sensitivity of Physiological Measures to Phobic and Nonphobic Fear Intensity

We investigated whether amygdala activation, autonomic responses, respiratory responses, and facial muscle activity (measured over the brow and cheek [fear grin] regions) are all sensitive to phobic versus nonphobic fear and, more importantly, whether effects in these variables vary as a function of both phobic and nonphobic fear intensity. Spider-phobic and comparably low spider-fearful control participants imagined encountering different animals and rated their subjective fear while their central and peripheral nervous system activity was measured. All measures included in our study were sensitive to variations in subjective fear, but were related to different ranges and positions on the subjective fear level continuum. Left amygdala activation, heart rate, and facial muscle activity over the cheek region captured fear intensity variations even within narrowly described regions on the fear level continuum (here within extremely low levels of fear and within considerable phobic fear). Skin conductance and facial muscle activity over the brow region did not capture fear intensity variations within low levels of fear: skin conductance mirrored only extreme levels of fear, and activity over the brow region distinguished phobic from nonphobic fear but also low-to-moderate and high phobic fear. Finally, respiratory measures distinguished phobic from nonphobic fear with no further differentiation within phobic and nonphobic fear. We conclude that a careful consideration of the measures to be used in an investigation and the population to be examined can be critical in order to obtain significant results

Stage-specific interventions for emotion dysregulation disorders in adolescents

Since most of the early signs of psychological distress are nonspecific and often under the threshold of a diagnosable disorder, especially in early adolescence, a dimensional and transdiagnostic approach is needed to guide early interventions. In this review, we focus on the transdiagnostic mechanism of emotion dysregulation hypothesised to underlie a group of psychopathologies that we named “emotion dysregulation disorders”. Some promising interventions useful at different stages of the evolution of such disorders (from subclinical to clinical ones) are briefly presented. Among them, we propose cognitive-behavioural therapies, mindfulness-based interventions, and mentalisation-based treatment. The mindfulness-based interventions are an essential part of our ongoing study on the effects of an 8-week regular practice of mindfulness on non-clinical adolescents between 13 and 15 years old. We finally conclude with a proposition for a potential clinical staging model for emotion dysregulation disorders

Biomarkers and vulnerability to bipolar disorders

Bipolar spectrum disorders are common and severe psychiatric diseases, with an important personal and societal burden. Current psychiatric neuroscience research combines different approaches in order to unravel the pathophysiology of the disease, and focuses on vulnerability factors. Here we review the main biological findings regarding trait markers of bipolar disorders, and how they can be considered as vulnerability factors in high-risk subjects, or biomarkers of illness progression or treatment response

Comportements auto-dommageables sans intention suicidaire et conduites suicidaires chez les jeunes: une revue de littérature narrative à la lumière du modèle d’Hamza et al. (2012)

Les comportements auto-dommageables sans intention suicidaire (CADSIS) et les conduites suicidaires (CS), incluant le suicide accompli, sont des problèmes de santé publique majeurs chez les adolescents et les jeunes adultes. Ils sont constatés de manière ubiquitaire, aussi bien dans des populations cliniques que communautaires. Bien que ces deux comportements coexistent fréquemment, les distinguer clairement reste complexe. En effet, les différences entre CADSIS et CS ont été davantage investiguées que leurs liens sous-jacents, tout comme les facteurs contribuant à la transition entre CADSIS et CS. Cette revue de littérature narrative vise à rendre compte de l’état actuel des connaissances concernant les articulations entre CADSIS et CS, à la lumière du modèle intégré de Hamza et al. qui propose des hypothèses de liens entre ces comportements. En addition à cet article, notre revue se base sur des articles postérieurs ou non-cités par Hamza et al., décrivant des études transversales, longitudinales et des méta-analyses ciblant les liens et/ou les différences entre CADSIS et CS chez des adolescents et jeunes adultes âgés de 12 à 25 ans. Au vu des différents résultats, le modèle d’Hamza et al. est intéressant car il intègre des facteurs de risques communs et une forme d’habituation pour expliquer la progression fréquente des CADSIS vers des CS. Cependant, si cette trajectoire est fréquente, elle n’est pas la règle. Il s’agirait dès lors de tester les liens et variables qui caractérisent potentiellement la relation CADSIS-CS selon leur modèle.Non-suicidal self-injuries (NSSI) and suicidal conduct (SC), including completed suicide, are major public health problems among adolescents and young adults. They are seen ubiquitously in both clinical and community populations. Although these two behaviors frequently co-exist, distinguishing them clearly remains complex. Indeed, the differences between NSSI and CS have been investigated more than their underlying relationships, as have the factors contributing to the transition between NSSI and CS. This narrative literature review aims to report on the current state of knowledge regarding the articulations between NSSI and CS, in light of Hamza et al.’s integrated model that proposes hypotheses of links between these behaviors. In addition to this article, our review is based on later articles or articles not cited by Hamza et al., describing cross-sectional, longitudinal, and meta-analyses targeting the links and/or differences between CADSIS and CS in adolescents and young adults aged 12 to 25 years. Based on the various findings, Hamza et al.’s model seems interesting because it incorporates common risk factors and a form of habituation to explain the frequent progression from CADSIS to CS. However, if this trajectory is frequent, it is not the rule. It would therefore be necessary to test all the links and variables that potentially mediate the CADSIS-CS relationship according to their model

Visual avoidance in phobia: particularities in neural activity, autonomic responding, and cognitive risk evaluations.

We investigated the neural mechanisms and the autonomic and cognitive responses associated with visual avoidance behavior in spider phobia. Spider phobic and control participants imagined visiting different forest locations with the possibility of encountering spiders, snakes, or birds (neutral reference category). In each experimental trial, participants saw a picture of a forest location followed by a picture of a spider, snake, or bird, and then rated their personal risk of encountering these animals in this context, as well as their fear. The greater the visual avoidance of spiders that a phobic participant demonstrated (as measured by eye tracking), the higher were her autonomic arousal and neural activity in the amygdala, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and precuneus at picture onset. Visual avoidance of spiders in phobics also went hand in hand with subsequently reduced cognitive risk of encounters. Control participants, in contrast, displayed a positive relationship between gaze duration toward spiders, on the one hand, and autonomic responding, as well as OFC, ACC, and precuneus activity, on the other hand. In addition, they showed reduced encounter risk estimates when they looked longer at the animal pictures. Our data are consistent with the idea that one reason for phobics to avoid phobic information may be grounded in heightened activity in the fear circuit, which signals potential threat. Because of the absence of alternative efficient regulation strategies, visual avoidance may then function to down-regulate cognitive risk evaluations for threatening information about the phobic stimuli. Control participants, in contrast, may be characterized by a different coping style, whereby paying visual attention to potentially threatening information may help them to actively down-regulate cognitive evaluations of risk

Resting-State EEG Microstates and Power Spectrum in Borderline Personality Disorder: A High-Density EEG Study

Borderline personality disorder (BPD) is a debilitating psychiatric condition characterized by emotional dysregulation, unstable sense of self, and impulsive, potentially self-harming behavior. In order to provide new neurophysiological insights on BPD, we complemented resting-state EEG frequency spectrum analysis with EEG microstates (MS) analysis to capture the spatiotemporal dynamics of large-scale neural networks. High-density EEG was recorded at rest in 16 BPD patients and 16 age-matched neurotypical controls. The relative power spectrum and broadband MS spatiotemporal parameters were compared between groups and their inter-correlations were examined. Compared to controls, BPD patients showed similar global spectral power, but exploratory univariate analyses on single channels indicated reduced relative alpha power and enhanced relative delta power at parietal electrodes. In terms of EEG MS, BPD patients displayed similar MS topographies as controls, indicating comparable neural generators. However, the MS temporal dynamics were significantly altered in BPD patients, who demonstrated opposite prevalence of MS C (lower than controls) and MS E (higher than controls). Interestingly, MS C prevalence correlated positively with global alpha power and negatively with global delta power, while MS E did not correlate with any measures of spectral power. Taken together, these observations suggest that BPD patients exhibit a state of cortical hyperactivation, represented by decreased posterior alpha power, together with an elevated presence of MS E, consistent with symptoms of elevated arousal and/or vigilance. This is the first study to investigate resting-state MS patterns in BPD, with findings of elevated MS E and the suggestion of reduced posterior alpha power indicating a disorder-specific neurophysiological signature previously unreported in a psychiatric population

Inflammation, anxiety, and stress in bipolar disorder and borderline personality disorder: A narrative review

Bipolar disorder (BD) and borderline personality disorder (BPD) are serious and prevalent psychiatric diseases that share common phenomenological characteristics: symptoms (such as anxiety, affective lability or emotion dysregulation), neuroimaging features, risk factors and comorbidities. While several studies have focused on the link between stress and peripheral inflammation in other affective disorders such as anxiety or depression, fewer have explored this relationship in BD and BPD. This review reports on evidence showing an interplay between immune dysregulation, anxiety and stress, and how an altered acute neuroendocrine stress response may exist in these disorders. Moreover, we highlight limitations and confounding factors of these existing studies and discuss multidirectional hypotheses that either suggest inflammation or stress and anxiety as the primum movens in BD and BPD pathophysiology, or inflammation as a consequence of the pathophysiology of these diseases. Untangling these associations and implementing a transdiagnostic approach will have diagnostic, therapeutic and prognostic implications for BD and BPD patients