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Indian Journal of Psychiatry 2021Dissociative experiences and health anxiety are frequently encountered in anxiety disorders and contribute to the burden of illness.
BACKGROUND
Dissociative experiences and health anxiety are frequently encountered in anxiety disorders and contribute to the burden of illness.
AIM
The aim was to assess and compare dissociative experiences and level of health anxiety in patients with panic disorder and normal individuals.
MATERIALS AND METHODS
We recruited forty eligible patients with panic disorder and forty healthy volunteers without any psychiatric diagnoses. Health anxiety was evaluated by the Short Health Anxiety Inventory and dissociative symptoms were assessed by the Dissociative Experiences Scale (DES).
RESULTS
Dissociative experiences were more frequently reported by patients with panic disorder compared to normal controls, but overall mean DES scores were lower in both groups compared to previous literature. A high level of health anxiety was also seen in panic disorder compared to normal individuals.
CONCLUSION
Health anxiety and dissociative experiences, especially depersonalization-derealization, are commonly encountered in panic disorder and should be actively explored to understand how they influence psychopathology and treatment outcome.
PubMed: 34083823
DOI: 10.4103/psychiatry.IndianJPsychiatry_896_20 -
Neuroscience and Biobehavioral Reviews Nov 2023For the past decade, ketamine, an N-methyl-D-aspartate receptor (NMDAr) antagonist, has been considered a promising treatment for major depressive disorder (MDD). Unlike... (Review)
Review
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.
Topics: Humans; Ketamine; Depressive Disorder, Major; Antidepressive Agents; Brain; Signal Transduction; Receptors, N-Methyl-D-Aspartate
PubMed: 37793581
DOI: 10.1016/j.neubiorev.2023.105410 -
Journal of Personalized Medicine Aug 2022Dissociative disorders encompass loss of integration in essential functions such as memory, consciousness, perception, motor control, and identity. Nevertheless,... (Review)
Review
BACKGROUND
Dissociative disorders encompass loss of integration in essential functions such as memory, consciousness, perception, motor control, and identity. Nevertheless, neuroimaging studies, albeit scarce, have suggested the existence of particular brain activation patterns in patients belonging to this diagnostic category. The aim of this review is to identify the main functional neuroimaging correlates of dissociative disorders.
METHODS
we searched the PubMed database to identify functional neuroimaging studies conducted on subjects with a diagnosis of a dissociative disorder, following the PRISMA guidelines. In the end, we included 13 studies in this systematic review, conducted on 51 patients with dissociative identity disorder (DID), 28 subjects affected by depersonalization disorder, 24 with dissociative amnesia, and 6 with other or not specified dissociative disorders.
RESULTS
Prefrontal cortex dysfunction seems prominent. In addition, changes in the functional neural network of the caudate are related to alterations of identity state and maintenance of an altered mental status in DID. Another role in DID seems to be played by a dysfunction of the anterior cingulate gyrus. Other regions, including parietal, temporal, and insular cortices, and subcortical areas were reported to be dysfunctional in dissociative disorders.
CONCLUSIONS
Prefrontal dysfunction is frequently reported in dissociative disorders. Functional changes in other cortical and subcortical areas can be correlated with these diagnoses. Further studies are needed to clarify the neurofunctional correlations of each dissociative disorder in affected patients, in order to identify better tailored treatments.
PubMed: 36143190
DOI: 10.3390/jpm12091405 -
Genes May 2022Dissociative disorders are a common and frequently undiagnosed group of psychiatric disorders, characterized by disruptions in the normal integration of awareness,... (Review)
Review
Dissociative disorders are a common and frequently undiagnosed group of psychiatric disorders, characterized by disruptions in the normal integration of awareness, personality, emotion and behavior. The available evidence suggests that these disorders arise from an interaction between genetic vulnerability and stress, particularly traumatic stress, but the attention paid to the underlying genetic diatheses has been sparse. In this paper, the existing literature on the molecular genetics of dissociative disorders, as well as of clinically significant dissociative symptoms not reaching the threshold of a disorder, is reviewed comprehensively across clinical and non-clinical samples. Association studies suggest a link between dissociative symptoms and genes related to serotonergic, dopaminergic and peptidergic transmission, neural plasticity and cortisol receptor sensitivity, particularly following exposure to childhood trauma. Genome-wide association studies have identified loci of interest related to second messenger signaling and synaptic integration. Though these findings are inconsistent, they suggest biologically plausible mechanisms through which traumatic stress can lead to pathological dissociation. However, methodological concerns related to phenotype definition, study power, and correction for the confounding factors limit the value of these findings, and they require replication and extension in studies with better design.
Topics: Dissociative Disorders; Emotions; Genome-Wide Association Study; Humans; Molecular Biology
PubMed: 35627228
DOI: 10.3390/genes13050843 -
Iranian Journal of Psychiatry Oct 2021Epidemiologic and etiological studies of dissociative disorders are a challenging area in psychiatry. These challenges become more complex when noting that the existing... (Review)
Review
Epidemiologic and etiological studies of dissociative disorders are a challenging area in psychiatry. These challenges become more complex when noting that the existing theories cannot explain the differences observed in certain cases; for example, studies in Iran have reported the prevalence of dissociative disorders (dissociative amnesia, dissociative fugue, and depersonalization disorder) as less than 0.6%, and there has been no reported case of dissociative identity disorder (DID) in this country; meanwhile, the prevalence of all dissociative disorders in the general population of the US has been reported as 18.3%, and the prevalence of DID as about 1.1%. Although several studies indicate the high prevalence of dissociative symptoms in many Iranian psychiatric illnesses, dissociative disorders as a stand-alone disorder have a very low prevalence in Iran. The present article attempts to propose a possible hypothesis for the answer to the above questions through a different cultural conceptualization and seeks to be of some help to future studies in this area. Certainly, this hypothesis requires a careful study to be validated.
PubMed: 35082859
DOI: 10.18502/ijps.v16i4.7234 -
Frontiers in Psychiatry 2022Dissociative disorders are an important group of trauma-related disorders associated with significant disability. The co-occurrence of dissociative disorders (DD) and... (Review)
Review
Dissociative disorders are an important group of trauma-related disorders associated with significant disability. The co-occurrence of dissociative disorders (DD) and symptoms (DS) in bipolar disorder has been relatively understudied, but there is some evidence that this comorbidity may have significant mechanistic and clinical implications. This paper presents the results of a scoping review of the frequency and correlates of DS and DD in bipolar disorder. Based on the available evidence, DS/DD are more common in bipolar disorder than in healthy controls or in unipolar depression, are related to childhood trauma, and are associated with psychotic symptoms, suicide attempts, and a poorer response to treatment in patients with bipolar disorder. The implications of these findings, and possible mechanistic pathways underlying them, are discussed based on the current literature. Clinicians should be aware of the frequent occurrence of significant DS or DD when treating patients with bipolar disorder. A tentative future research agenda for this field, based on clinical, risk factor-related and neurobiological considerations, is outlined.
PubMed: 35722564
DOI: 10.3389/fpsyt.2022.925983 -
Nature Communications Dec 2020Ketamine produces immediate antidepressant effects and has inspired research into next-generation treatments. Ketamine also has short term dissociative effects, in which... (Review)
Review
Ketamine produces immediate antidepressant effects and has inspired research into next-generation treatments. Ketamine also has short term dissociative effects, in which individuals report altered consciousness and perceptions of themselves and their environment. However, whether ketamine's dissociative side effects are necessary for its antidepressant effects remains unclear. This perspective examines the relationship between dissociative effects and acute and longer-lasting antidepressant response to ketamine and other N-methyl-D-aspartate (NMDA) receptor antagonists. Presently, the literature does not support the conclusion that dissociation is necessary for antidepressant response to ketamine. However, further work is needed to explore the relationship between dissociation and antidepressant response at the molecular, biomarker, and psychological levels.
Topics: Animals; Antidepressive Agents; Dissociative Disorders; Humans; Ketamine; Receptors, N-Methyl-D-Aspartate
PubMed: 33353946
DOI: 10.1038/s41467-020-20190-4 -
Psychiatria Polska Feb 2020Mental disorders occur in patients with epilepsy significantly more frequently than in the general population or in those with other chronic diseases. The specificity of... (Review)
Review
Mental disorders occur in patients with epilepsy significantly more frequently than in the general population or in those with other chronic diseases. The specificity of epilepsy as a condition of the central nervous system with complex somatic, psychic and social consequences contributes to co-occurrence of these disorders. Moreover, common patomechanisms are suggested for epilepsy and mental disorders, associated with disturbances of bioelectrical activity and neurotransmission in certain areas of the brain.The authors present a review of main groups of mental disorders observed in epileptic patients: psychotic, affective, anxiety, personality, and conduct disorders. They discuss their epidemiology and clinical presentation, with a particular focus on their risk factors and temporal relation to epileptic seizures. They also highlight problems associated with differential diagnosis and optimal therapeutic strategy. Mental disorders have a significant impact on the quality of life and functioning of patients with epilepsy. Further exploration of interrelationships between these illnesses, as well as cooperation between neurologists and psychiatrists promote an early and precise diagnosis of mental disturbances in this group of patients and their effective treatment.
Topics: Adult; Affective Symptoms; Antisocial Personality Disorder; Dissociative Disorders; Epilepsy; Female; Humans; Male; Mental Disorders; Prevalence; Quality of Life; Risk Factors; Somatoform Disorders
PubMed: 32447356
DOI: 10.12740/PP/93886 -
Neuroscience and Biobehavioral Reviews Aug 2022Elevated responsiveness to verbal suggestions is hypothesized to represent a predisposing factor for the dissociative disorders (DDs) and related conditions. However,... (Meta-Analysis)
Meta-Analysis Review
Elevated responsiveness to verbal suggestions is hypothesized to represent a predisposing factor for the dissociative disorders (DDs) and related conditions. However, the magnitude of this effect has not been estimated in these populations nor has the potential moderating influence of methodological limitations on effect size variability across studies. This study assessed whether patients with DDs, trauma- and stressor-related disorders (TSDs), and functional neurological disorder (FND) display elevated hypnotic suggestibility. A systematic literature search identified 20 datasets. A random-effects meta-analysis revealed that patients displayed greater hypnotic suggestibility than controls, Hedges's g = 0.92 [0.66, 1.18]. This effect was observed in all subgroups but was most pronounced in the DDs. Although there was some evidence for publication bias, a bias-corrected estimate of the group effect remained significant, g = 0.57 [0.30, 0.85]. Moderation analyses did not yield evidence for a link between effect sizes and methodological limitations. These results demonstrate that DDs and related conditions are characterized by elevated hypnotic suggestibility and have implications for the mechanisms, risk factors, and treatment of dissociative psychopathology.
Topics: Dissociative Disorders; Humans; Hypnosis; Hypnotics and Sedatives; Suggestion
PubMed: 35760389
DOI: 10.1016/j.neubiorev.2022.104751 -
BJPsych Open Dec 2022Studies have reported elevated rates of dissociative symptoms and comorbid dissociative disorders in functional neurological disorder (FND); however, a comprehensive... (Review)
Review
BACKGROUND
Studies have reported elevated rates of dissociative symptoms and comorbid dissociative disorders in functional neurological disorder (FND); however, a comprehensive review is lacking.
AIMS
To systematically review the severity of dissociative symptoms and prevalence of comorbid dissociative disorders in FND and summarise their biological and clinical associations.
METHOD
We searched Embase, PsycInfo and MEDLINE up to June 2021, combining terms for FND and dissociation. Studies were eligible if reporting dissociative symptom scores or rates of comorbid dissociative disorder in FND samples. Risk of bias was appraised using modified Newcastle-Ottawa criteria. The findings were synthesised qualitatively and dissociative symptom scores were included in a meta-analysis (PROSPERO CRD42020173263).
RESULTS
Seventy-five studies were eligible (FND = 3940; control = 3073), most commonly prospective case-control studies ( = 54). Dissociative disorders were frequently comorbid in FND. Psychoform dissociation was elevated in FND compared with healthy ( = 0.90, 95% CI 0.66-1.14, = 70%) and neurological controls ( = 0.56, 95% CI 0.19-0.92, = 67%). Greater psychoform dissociation was observed in FND samples with seizure symptoms versus healthy controls ( = 0.94, 95% CI 0.65-1.22, = 42%) and FND samples with motor symptoms ( = 0.40, 95% CI -0.18 to 1.00, = 54%). Somatoform dissociation was elevated in FND versus healthy controls ( = 1.80, 95% CI 1.25-2.34, = 75%). Dissociation in FND was associated with more severe functional symptoms, worse quality of life and brain alterations.
CONCLUSIONS
Our findings highlight the potential clinical utility of assessing patients with FND for dissociative symptomatology. However, fewer studies investigated FND samples with motor symptoms and heterogeneity between studies and risk of bias were high. Rigorous investigation of the prevalence, features and mechanistic relevance of dissociation in FND is needed.
PubMed: 36451595
DOI: 10.1192/bjo.2022.597