-
PloS One 2021Dissociative experiences occur across a range of mental health disorders. However, the term 'dissociation' has long been argued to lack conceptual clarity and may...
BACKGROUND
Dissociative experiences occur across a range of mental health disorders. However, the term 'dissociation' has long been argued to lack conceptual clarity and may describe several distinct phenomena. We therefore aimed to conceptualise and empirically establish a discrete subset of dissociative experiences and develop a corresponding assessment measure.
METHODS
First, a systematic review of existing measures was carried out to identify themes across dissociative experiences. A theme of 'Felt Sense of Anomaly' (FSA) emerged. Second, assessment items were generated based on this construct and a measure developed using exploratory (EFA) and confirmatory (CFA) factor analyses of 8861 responses to an online self-report survey. Finally, the resulting measure was validated via CFA with data from 1031 patients with psychosis.
RESULTS
'Felt sense of anomaly' (FSA) was identified as common to many dissociative experiences, affecting several domains (e.g. body) and taking different forms ('types'; e.g. unfamiliarity). Items for a novel measure were therefore systematically generated using a conceptual framework whereby each item represented a type-by-domain interaction (e.g. 'my body feels unfamiliar'). Factor analysis of online responses found that FSA-dissociation manifested in seven ways: anomalous experiences of the self, body, and emotion, and altered senses of familiarity, connection, agency, and reality (Χ2 (553) = 4989.435, p<0.001, CFI = 0.929, TLI = 0.924, RMSEA = 0.052, SRMR = 0.047). Additionally, a single-factor 'global FSA' scale was produced (Χ2 (9) = 312.350, p<0.001, CFI = 0.970, TLI = 0.950, RMSEA = 0.107, SRMR = 0.021). Model fit was adequate in the clinical (psychosis) group (Χ2 (553) = 1623.641, p<0.001, CFI = 0.927, TLI = 0.921, RMSEA = 0.043, SRMR = 0.043). The scale had good convergent validity with a widely used dissociation scale (DES-II) (non-clinical: r = 0.802), excellent internal reliability (non-clinical: Cronbach's alpha = 0.98; clinical: Cronbach's alpha = 0.97), and excellent test-retest reliability (non-clinical: ICC = 0.92). Further, in non-clinical respondents scoring highly on a PTSD measure, CFA confirmed adequate model fit (Χ2 (553) = 4758.673, CFI = 0.913, TLI = 0.906, RMSEA = 0.052, SRMR = 0.054).
CONCLUSIONS
The Černis Felt Sense of Anomaly (ČEFSA) scale is a novel measure of a subset of dissociative experiences that share a core feature of FSA. It is psychometrically robust in both non-clinical and psychosis groups.
Topics: Dissociative Disorders; Factor Analysis, Statistical; Humans; Psychometrics; Self Report
PubMed: 33626089
DOI: 10.1371/journal.pone.0247037 -
Frontiers in Psychiatry 2023Dissociative amnesia is an emblematic psychiatric condition in which patients experience massive memory loss ranging from focal to global amnesia. This condition remains... (Review)
Review
AIM
Dissociative amnesia is an emblematic psychiatric condition in which patients experience massive memory loss ranging from focal to global amnesia. This condition remains poorly understood and this review aims to investigate the neuroanatomical feature of this disease.
METHODS
We conducted a systematic review of the scientific literature available on PubMed, up to December 1, 2022, using a combination of keywords referring to dissociative amnesia. We included every scientific report involving patients undergoing a functional imaging procedure.
RESULTS
Twenty-two studies met our inclusion criteria (gathering 49 patients). Only one was a controlled study with a large sample. The other 21 were case reports and case series. In resting state, neuroimaging studies mostly showed a hypo-activated right inferolateral prefrontal cortex, associated with limbic hypoactivity and lesser activation of the hippocampal and para-hippocampal structures. The patients also presented abnormal patterns of cerebral activation when performing memory tasks. When testing recognition of memories from the amnestic period, patients showed increased activation across temporal areas (hippocampal and para-hippocampal gyri) and the limbic network. When trying to recollect memories from an amnestic period compared to a non-amnestic period, patients failed to activate these structures efficiently. Most of these patterns tended to return to normal when symptoms resolved.
CONCLUSION
This review identified a paucity of controlled studies in the field of dissociative amnesia neuroimaging, which restricts the extrapolation of results. Patients with dissociative amnesia present a broad prefronto-temporo-limbic network dysfunction. Some of the brain areas implicated in this network might represent potential targets for innovative treatments.
PubMed: 36778638
DOI: 10.3389/fpsyt.2023.1092826 -
Psychopharmacology Sep 2014Ketamine's efficacy in depressive disorders has been established in several controlled trials. The aim of the present study was to determine whether or not ketamine... (Meta-Analysis)
Meta-Analysis Review
INTRODUCTION
Ketamine's efficacy in depressive disorders has been established in several controlled trials. The aim of the present study was to determine whether or not ketamine administration significantly improves depressive symptomatology in depression and more specifically in major depressive disorder (MDD), bipolar depression, resistant depression (non-ECT studies), and as an anesthetic agent in electroconvulsive therapy (ECT) for resistant depression (ECT studies). Secondary outcomes were the duration of ketamine's effect, the efficacy on suicidal ideations, the existence of a dose effect, and the safety/tolerance of the treatment.
METHODS
Studies were included if they met the following criteria (without any language or date restriction): design: randomized controlled trials, intervention: ketamine administration, participants: diagnosis of depression, and evaluation of severity based on a validated scale. We calculated standardized mean differences (SMDs) with 95 % confidence intervals (CIs) for each study. We used fixed and random effects models. Heterogeneity was assessed using the I2 statistic.
RESULTS
We included nine non-ECT studies in our quantitative analysis (192 patients with major depressive disorder and 34 patients with bipolar depression). Overall, depression scores were significantly decreased in the ketamine groups compared to those in the control groups (SMD = -0.99; 95 % CI -1.23, -0.75; p < 0.01). Ketamine's efficacy was confirmed in MDD (resistant to previous pharmacological treatments or not) (SMD = -0.91; 95 % CI -1.19,-0.64; p < 0.01), in bipolar depression (SMD = -1.34; 95 % CI -1.94, -0.75), and in drug-free patients as well as patients under medication. Four ECT trials (118 patients) were included in our quantitative analysis. One hundred and three patients were diagnosed with major depressive disorder and 15 with bipolar depression. Overall, depression scores were significantly improved in the 58 patients receiving ketamine in ECT anesthesia induction compared to the 60 patients (SMD = -0.56; 95 % CI -1.10, -0.02; p = 0.04; I2 = 52.4 %). The duration of ketamine's effects was assessed in only two non-ECT studies and seemed to persist for 2-3 days; this result needs to be confirmed. Three of four studies found significant decrease of suicidal thoughts and one found no difference between groups, but suicidal ideations were only studied by the suicide item of the depressive scales. It was not possible to determine a dose effect; 0.5 mg/kg was used in the majority of the studies. Some cardiovascular events were described (mostly transient blood pressure elevation that may require treatment), and ketamine's use should remain cautious in patients with a cardiovascular history.
CONCLUSION
The present meta-analysis confirms ketamine's efficacy in depressive disorders in non-ECT studies, as well as in ECT studies. The results of this first meta-analysis are encouraging, and further studies are warranted to detail efficacy in bipolar disorders and other specific depressed populations. Middle- and long-term efficacy and safety have yet to be explored. Extrapolation should be cautious: Patients included had no history of psychotic episodes and no history of alcohol or substance use disorders, which is not representative of all the depressed patients that may benefit from this therapy.
Topics: Anesthetics, Dissociative; Antidepressive Agents; Bipolar Disorder; Depressive Disorder, Major; Depressive Disorder, Treatment-Resistant; Electroconvulsive Therapy; Humans; Ketamine
PubMed: 25038867
DOI: 10.1007/s00213-014-3664-5 -
Psychological Medicine Feb 2022Adverse life events precede the onset of functional neurological disorder (FND, also known as conversion disorder) more commonly than other neuropsychiatric conditions,... (Meta-Analysis)
Meta-Analysis Review
Adverse life events precede the onset of functional neurological disorder (FND, also known as conversion disorder) more commonly than other neuropsychiatric conditions, but their aetiological role is unclear. We conducted a systematic review and quantitative analysis of the type, timing and number of life events preceding the onset of FND in adults, and a meta-analysis of the proportions of types of events in controlled studies. Fifty-one studies of different designs, covering 4247 patients, were eligible for inclusion. There was no clear majority of any type of preceding event. Family problems were the most common category of events, followed by relationship problems. Females were more likely to experience preceding family/relationship problems than males, who reported more work problems. Family problems were the commonest type of preceding event in studies in developing countries, whereas family and health problems were equally common in developed countries. Abuse was associated with early symptom onset, while patients with later onset were more likely to report family problems. The median number of events was one, and the events occurred closer to onset than in controls. Meta-analysis found that family, relationship and work events were all relatively more common in patients than pathological controls, as were events where symptoms might provide a solution to the stressor. In conclusion, although a range of events precede the onset of FND, they do not appear to do so uniformly. This may support a different aetiological role for stressors than in other disorders, although the support is indirect and the quality generally low.
Topics: Adult; Conversion Disorder; Dissociative Disorders; Female; Humans; Male
PubMed: 34819179
DOI: 10.1017/S0033291721004669 -
Journal of Psychosomatic Research May 2023Patients with functional neurological disorders (FND) present with weakness, sensory or movement disorder without corresponding brain pathology. The current... (Review)
Review
INTRODUCTION
Patients with functional neurological disorders (FND) present with weakness, sensory or movement disorder without corresponding brain pathology. The current classificatory systems suggest an inclusionary approach to diagnose FND. Hence, there is a need to systematically evaluate the diagnostic accuracy of clinical signs and electrophysiological investigations in view of the lack of gold standard tests to diagnose FND.
METHODS
PubMed and SCOPUS databases were searched for studies published from Jan 1950 to Jan 2022 which reported the diagnostic accuracy of clinical signs and electrophysiological investigations in patients with FND. The Newcastle Ottawa scale was used to assess the quality of the studies.
RESULTS
Twenty-one studies (727 cases and 932 controls), of which 16 reported clinical signs and, five reported electrophysiological investigations, were included in the review. Two studies were of good quality, 17 of moderate quality, and two of poor quality. We identified 46 clinical signs (24 in weakness, 3 in sensory, and 19 in movement disorders) and 17 investigations (all in movement disorders). Specificity values for signs and investigations were comparatively high compared to the wide variance in sensitivity values.
CONCLUSION
Electrophysiological investigations appear to have a promising role in diagnosing FND, particularly functional movement disorders. The combined use of individual clinical signs and electrophysiological investigations may support and improve diagnostic certainty of FND. Future research can focus on improving the methodology and validating the existing clinical signs and electrophysiological investigations to enhance the validity of the composite diagnostic criterias for FND diagnosis.
Topics: Humans; Nervous System Diseases; Movement Disorders; Conversion Disorder
PubMed: 36868109
DOI: 10.1016/j.jpsychores.2023.111196 -
Journal of Affective Disorders Apr 2017The dissociative PTSD (D-PTSD) subtype was first introduced into the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. Prior to... (Review)
Review
BACKGROUND
The dissociative PTSD (D-PTSD) subtype was first introduced into the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) in 2013. Prior to this, studies using latent profile analysis (LPA) or latent class analysis (LCA), began to provide support for the D-PTSD construct and associated risk factors. This research is important, because dissociative symptoms in the context of PTSD may potentially interfere with treatment course or outcome. The aims of the present study were twofold: to systematically review the LCA and LPA studies investigating support for the D-PTSD construct; and to review the associated research on the risk factors or covariates of D-PTSD in the identified studies.
METHOD
Six databases (PubMed, Web of Science, Scopus, PILOTS, PsychInfo, and Embase) were systematically searched for relevant papers.
RESULTS
Eleven studies were included in the present review. The majority of the studies were supportive of the D-PTSD subtype; primarily characterized by depersonalization and derealization. Several covariates of the D-PTSD subtype have been investigated with mixed results.
LIMITATIONS
Many limitations relate to the state of the current literature, including a small number of studies, the use of self-report measurements of PTSD, and heterogeneity across the samples in investigated covariates.
CONCLUSION
The results were overall supportive of the D-PTSD construct. Future research on D-PTSD and associated risk factors is needed to shed light on the possibilities of facilitating preventive actions, screening, and implications on treatment effects.
Topics: Depersonalization; Diagnostic and Statistical Manual of Mental Disorders; Dissociative Disorders; Humans; Risk Factors; Self Report; Stress Disorders, Post-Traumatic
PubMed: 28192736
DOI: 10.1016/j.jad.2017.02.004 -
European Journal of Psychotraumatology 2022Neurophysiological models link dissociation (e.g. feeling detached during or after a traumatic event) to hypoarousal. It is currently assumed that the initial passive... (Review)
Review
Trauma-related dissociation and the autonomic nervous system: a systematic literature review of psychophysiological correlates of dissociative experiencing in PTSD patients.
Neurophysiological models link dissociation (e.g. feeling detached during or after a traumatic event) to hypoarousal. It is currently assumed that the initial passive reaction to a threat may coincide with a blunted autonomic response, which constitutes the dissociative subtype of post-traumatic stress disorder (PTSD). Within this systematic review we summarize research which evaluates autonomic nervous system activation (e.g. heart rate, blood pressure) and dissociation in PTSD patients to discern the validity of current neurophysiological models of trauma-related hypoarousal. Of 553 screened articles, 28 studies ( = 1300 subjects) investigating the physiological response to stress provocation or trauma-related interventions were included in the final analysis. No clear trend exists across all measured physiological markers in trauma-related dissociation. Extracted results are inconsistent, in part due to high heterogeneity in experimental methodology. The current review is unable to provide robust evidence that peri- and post-traumatic dissociation are associated with hypoarousal, questioning the validity of distinct psychophysiological profiles in PTSD.
Topics: Humans; Stress Disorders, Post-Traumatic; Dissociative Disorders; Autonomic Nervous System; Heart Rate; Psychophysiology
PubMed: 36340007
DOI: 10.1080/20008066.2022.2132599 -
Neuroscience and Biobehavioral Reviews Jun 2018The present review aimed to 1) identify what sleep disturbances co-occur alongside psychotic-like, dissociative and hypomanic experiences; 2) assess the strength of...
Are sleep disturbances causally linked to the presence and severity of psychotic-like, dissociative and hypomanic experiences in non-clinical populations? A systematic review.
The present review aimed to 1) identify what sleep disturbances co-occur alongside psychotic-like, dissociative and hypomanic experiences; 2) assess the strength of potential associations between the severity of sleep disturbances and of the experiences studied; and 3) appraise evidence for a causal link. MedLine and PsycInfo were searched and 44 studies were deemed eligible. Results showed that insomnia was associated with all individual psychotic-like, dissociative and hypomanic experiences reviewed (effect size range: small-to-large). Parasomnias were associated with all psychotic-like experiences; however, there was evidence of variation in magnitude between individual experiences. An eveningness chronotype was associated with dissociative and hypomanic experiences, and circadian dysrhythmia was found alongside hypomania but not the other experiences reviewed. Finally, experimental sleep manipulation studies revealed a potential causal link between sleep loss and psychotic-like and dissociative experiences, although size and consistency of effects varied by specific experience. Future research, using experimental manipulations of sleep to address putative mechanisms, will enable questions of causality to be answered with more confidence.
Topics: Chronobiology Disorders; Humans; Psychotic Disorders; Sample Size; Sleep; Sleep Initiation and Maintenance Disorders; Sleep Wake Disorders
PubMed: 29452128
DOI: 10.1016/j.neubiorev.2018.02.008 -
AIMS Neuroscience 2021The temporal-parietal junction (TPJ) is a key structure for the embodiment, term referred to as the sense of being localized within one's physical body and is a... (Review)
Review
Targeting temporal parietal junction for assessing and treating disembodiment phenomena: a systematic review of TMS effect on depersonalization and derealization disorders (DPD) and body illusions.
The temporal-parietal junction (TPJ) is a key structure for the embodiment, term referred to as the sense of being localized within one's physical body and is a fundamental aspect of the self. On the contrary, the sense of disembodiment, an alteration of one's sense of self or the sense of being localized out of one's physical body, is a prominent feature in specific dissociative disorders, namely depersonalization/derealization disorders (DPD). The aims of the study were to provide: 1) a qualitative synthesis of the effect of Transcranial Magnetic Stimulation (TMS), taking into account its use for therapeutic and experimental purposes; 2) a better understanding on whether the use of TMS could support the treatment of DPD and other clinical conditions in which depersonalization and derealization are displayed. To identify suitable publications, an online search of the PubMed, Cochrane Library, Web of science and Scopus databases was performed using relevant search terms. In addition, an in-depth search was performed by screening review articles and the references section of each included articles. Our search yielded a total of 108 records through multiple databases searching and one additional record was identified through other sources. After duplicates removal, title and abstract reading, we retained 16 records for the assessment of eligibility. According to our inclusion criteria, we retained 8 studies. The selected studies showed that TMS targeting the TPJ is a promising technique for treating disembodiment phenomena DPD and for inducing reversible disembodiment states in healthy subjects. These data represent the first step towards a greater understanding of possible treatments to be used in disembodiment disorders. The use of TMS over the TPJ appears to be promising for treating disembodiment phenomena.
PubMed: 33709023
DOI: 10.3934/Neuroscience.2021009 -
Genes Jul 2023Evidence on the genetics of functional seizures is scarce, and the purpose of the current scoping systematic review is to examine the existing evidence and propose how...
BACKGROUND
Evidence on the genetics of functional seizures is scarce, and the purpose of the current scoping systematic review is to examine the existing evidence and propose how to advance the field.
METHODS
Web of science and MEDLINE were searched, from their initiation until May 2023. The following key words were used: functional neurological disorder(s), psychogenic neurological disorder(s), functional movement disorder(s), psychogenic movement disorder(s), functional seizures(s), psychogenic seizure(s), nonepileptic seizure(s), dissociative seizure(s), or psychogenic nonepileptic seizure(s), AND, gene, genetic(s), polymorphism, genome, epigenetics, copy number variant, copy number variation(s), whole exome sequencing, or next-generation sequencing.
RESULTS
We identified three original studies. In one study, the authors observed that six (5.9%) patients with functional seizures carried pathogenic/likely pathogenic variants. In another study, the authors observed that, in functional seizures, there was a significant correlation with genes that are over-represented in adrenergic, serotonergic, oxytocin, opioid, and GABA receptor signaling pathways. In the third study, the authors observed that patients with functional seizures, as well as patients with depression, had significantly different genotypes in single nucleotide polymorphisms compared with controls.
CONCLUSION
Future genetic investigations of patients with functional seizures would increase our understanding of the pathophysiological and neurobiological problems underlying this common neuropsychological stress-associated condition.
Topics: Humans; Analgesics, Opioid; Cognition; DNA Copy Number Variations; Genotype; Seizures
PubMed: 37628589
DOI: 10.3390/genes14081537