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Neuroscience Research Jul 2020Using high resolution spectral methods to uncover neuromarkers of social, cognitive and behavioral function, we have found that hemi-lateralized pairs of oscillations...
Using high resolution spectral methods to uncover neuromarkers of social, cognitive and behavioral function, we have found that hemi-lateralized pairs of oscillations such as left and right occipital alpha or left and right rolandic mu dissociate spectrally. That is, they show a shifted frequency distribution, with one member of the pair peaking at a slightly lower frequency than the other. Resorting to the analysis of EEG spatio-spectral patterns, we provide examples of dissociations in the 10Hz frequency band. Occasionally, hemi-lateralized pairs blend into medial aggregates, probably when functional interactions lead to strongly coherent dynamics through frequency-locking or metastability. Our observations support the hypothesis that homologous pairs of neuromarkers have characteristically distinct intrinsic frequencies and coordinate their oscillations into synchronous ensembles only transiently. This property could play a role in the balance of integration and segregation in the brain: spectral separation of the oscillations from homologous cortical areas allows them to function independently under certain circumstances, all the while preserving a potential for stronger interactions supported by structural and functional symmetries. Spectral dissociation (and its methodological corollary: spectral analysis with high frequency resolution) may be harnessed to better track the individual power of each member of a hemi-lateralized pair and their respective time-course, leading to enhanced internal validity and reproducibility of research on neural oscillations. Resulting insights may shed light on the functional interaction between homologous cortices in studies of attention (alpha), e.g. during perceptual and social interaction tasks, and in studies of somatomotor processing (mu), e.g. in bimanual coordination and neuroprosthetics.
Topics: Attention; Brain; Dissociative Disorders; Electroencephalography; Humans; Reproducibility of Results
PubMed: 31883870
DOI: 10.1016/j.neures.2019.12.006 -
Neuropsychologia Sep 2016Dissociative experiences, involving altered states of consciousness, have long been understood as a consequence or response to traumatic experiences, where a reduced... (Review)
Review
Dissociative experiences, involving altered states of consciousness, have long been understood as a consequence or response to traumatic experiences, where a reduced level of consciousness may aid in survival during and after a traumatic event. Indeed, the dissociative subtype of post-traumatic stress disorder (PTSD-DS) was added recently to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5). Dissociative symptoms are present across a host of neuropsychiatric conditions, including PTSD, psychotic spectrum illnesses, anxiety and mood disorders. Transdiagnostically, the presence of dissociative symptoms is associated with a greater illness burden and reduced treatment outcomes. Critically, dissociative symptoms are related to impaired performance on measures of attention, executive functioning, memory, and social cognition and may contribute to the widespread cognitive dysfunction observed across psychiatric illnesses. Despite this knowledge, the relation between dissociative symptoms and reduced cognitive function remains poorly understood. Here, we review the evidence linking dissociative symptoms to cognitive dysfunction across neuropsychiatric disorders. In addition, we explore two potential neurobiological mechanisms that may underlie the relation between dissociative symptoms and cognitive dysfunction in trauma-related neuropsychiatric conditions. Specifically, we hypothesize that: 1) functional sensory deafferentation at the level of the thalamus, as observed in the defence cascade model of dissociation, may underlie reduced attention and arousal leading to progressive cognitive dysfunction and; 2) altered functional connectivity between key brain networks implicated in cognitive functioning may represent a critical neurobiological mechanism linking dissociative symptoms and cognitive dysfunction in patients with PTSD-DS and transdiagnostically.
Topics: Cognition Disorders; Dissociative Disorders; Executive Function; Humans; Memory Disorders; Mental Disorders; Military Psychiatry; Social Behavior
PubMed: 27444881
DOI: 10.1016/j.neuropsychologia.2016.07.017 -
Medicine Aug 2021Endometrial tissue plays an important role in the regulation of female fertility and there is evidence that endometrial pathology (including endometriosis) is closely...
BACKGROUND
Endometrial tissue plays an important role in the regulation of female fertility and there is evidence that endometrial pathology (including endometriosis) is closely related to endocrine disorders. On the other hand, various neuroendocrine changes can be significantly affected by psychosocial stress. In connection with these findings, we tested the relationship between neuroendocrine changes, sexual dysfunction, psychosocial/traumatic stress, and dissociative symptoms in women with endometriosis.
METHODS
A total of 65 patients with endometriosis were included in the study. Clinical examinations were focused on the biochemical analysis of neuroendocrine markers of endometriosis (cancer antigen 125 [CA 125] and cancer antigen 19-9 [CA 19-9]), estradiol, psychometric evaluation of sexual dysfunction, psychosocial/traumatic stress, and dissociative symptoms.
RESULTS
The results showed significant Spearman correlations between the values of the revised range of sexual difficulties for sexual dysfunction (Revised Female Sexual Distress Scale), psychosocial/traumatic stress (Trauma Symptoms Checklist) (R = 0.31), and dissociative symptoms (Somatoform Dissociation Questionnaire) (R = 0.33). Positive correlations were also found between CA 125 and CA 19-9 (R = 0.63), and between CA 125 and the results of the values of the revised scale of sexual difficulties for sexual dysfunction (Revised Female Sexual Distress Scale) (R = 0.29). Also psychosocial/traumatic stress (Trauma Symptoms Checklist) significantly correlated with CA 125 (R = 0.38) and with CA 19-9 (R = 0.33).
CONCLUSION
These results represent the first findings regarding the relationship of the neuroendocrine markers CA 125 and CA 19-9 and sexual dysfunction with trauma/stress-related symptoms and dissociative symptoms in women with endometriosis.
Topics: Adult; CA-125 Antigen; CA-19-9 Antigen; Correlation of Data; Dissociative Disorders; Endometriosis; Female; Humans; Neurosecretory Systems; Psychological Techniques; Psychological Trauma; Psychology; Sexual Dysfunction, Physiological; Somatoform Disorders
PubMed: 34397850
DOI: 10.1097/MD.0000000000026836 -
Psychiatry Research Sep 2022The dissociative disorders and germane conditions are reliably characterized by elevated responsiveness to direct verbal suggestions. However, it remains unclear whether...
The dissociative disorders and germane conditions are reliably characterized by elevated responsiveness to direct verbal suggestions. However, it remains unclear whether atypical responsiveness to suggestion is similarly present in depersonalization-derealization disorder (DDD). 55 DDD patients and 36 healthy controls completed a standardised behavioural measure of direct verbal suggestibility that includes a correction for compliant responding (BSS-C), and psychometric measures of depersonalization-derealization (CDS), mindfulness (FFMQ), imagery vividness (VVIQ), and anxiety (GAD-7). Relative to controls, patients did not exhibit elevated suggestibility (g = 0.26, BF = .11) but displayed significantly lower mindfulness (g = 1.38), and imagery vividness (g = 0.63), and significantly greater anxiety (g = 1.39). Although suggestibility did not correlate with severity of depersonalization-derealization symptoms in controls, r = -.03 [95% CI: -.36, .30], there was a weak tendency for a positive association in patients, r = .25, [95% CI: -.03, .48]. Exploratory analyses revealed that patients with more severe anomalous bodily experiences were also more responsive to suggestion, an effect not seen in controls. This study demonstrates that DDD is not characterized by elevated responsiveness to direct verbal suggestions. These results have implications for the aetiology and treatment of this condition, as well as its classification as a dissociative disorder in psychiatric nosology.
Topics: Anxiety; Depersonalization; Dissociative Disorders; Humans; Suggestion
PubMed: 35870293
DOI: 10.1016/j.psychres.2022.114730 -
International Journal of Environmental... Nov 2021The Duration of Untreated Psychosis (DUP) is the time between the first-episode psychosis (FEP) and the initiation of antipsychotic treatment. It is an important... (Observational Study)
Observational Study
Duration of Untreated Disorder and Cannabis Use: An Observational Study on a Cohort of Young Italian Patients Experiencing Psychotic Experiences and Dissociative Symptoms.
BACKGROUND
The Duration of Untreated Psychosis (DUP) is the time between the first-episode psychosis (FEP) and the initiation of antipsychotic treatment. It is an important predictor of several disease-related outcomes in psychotic disorders. The aim of this manuscript is investigating the influence of cannabis on the DUP and its clinical correlates.
METHODS
During years 2014-2019, sixty-two FEP patients with and without cannabis use disorder (CUD) were recruited from several Italian psychiatric hospitals. The subjects were then divided into two groups based on the duration of the DUP and assessed at the beginning of the antipsychotic treatment and after 3 and 6 months, using the Positive and Negative Syndrome Scale (PANSS), the Global Assessment of Functioning (GAF) scale, and the Dissociative Experiences Scale (DES-II).
RESULTS
As expected, a longer DUP was associated with worse symptoms and cannabis use did not seem to affect the DUP, but both were related with more dissociative symptoms at onset and over time.
DISCUSSION
According to our study, cannabis use can be a predictor of FEP and DUP, and of disease outcome. However, several factors might influence the relationship between cannabis use and DUP. Preventing cannabis use and early diagnosis of psychotic disorders might impact the disease by reducing the persistence of symptoms and limiting dissociative experiences.
Topics: Antipsychotic Agents; Cannabis; Dissociative Disorders; Hallucinogens; Humans; Psychotic Disorders
PubMed: 34886357
DOI: 10.3390/ijerph182312632 -
BMC Psychiatry May 2021Although numerous studies have supported the role of childhood maltreatment in the etiology of psychosis, underlying mechanisms have not been well understood yet. The...
BACKGROUND
Although numerous studies have supported the role of childhood maltreatment in the etiology of psychosis, underlying mechanisms have not been well understood yet. The present study aimed to investigate the mediating role of particular forms of dissociation in the relationship between five major types of childhood abuse and psychotic symptoms among patients with schizophrenia spectrum and other psychotic disorders.
METHODS
In this cross-sectional correlation study, 70 first-episode psychotic patients and 70 chronic psychotic patients were selected by systematic random sampling (with the sampling interval of 3) from among inpatients and outpatients referring to Baharan Psychiatric hospital, Zahedan, Iran, and were matched based on age, gender, and education level. Moreover, 70 age-, gender-, and education level-matched community controls were recruited from hospital staff and their relatives and friends. All of the participants completed a research interview and questionnaires. Data on experiences of childhood maltreatment, psychosis, dissociation, and demographics were collected and analyzed by SPSS V25 software.
RESULTS
The obtained results revealed that the mean scores of sexual abuse, emotional abuse, and physical abuse were higher in psychotic patients than community controls (without any significant difference between first-episode psychotic patients and chronic psychotic patients). Furthermore, the highest mean scores of dissociative experiences belonged to chronic psychotic patients. Multiple-mediation also indicated that absorption and dissociative amnesia played a mediating role in the relationship between sexual abuse and positive symptoms. Moreover, this study demonstrated the role of physical abuse in predicting psychotic symptoms even in the absence of sexual abuse.
CONCLUSIONS
This study illustrated specific associations among childhood maltreatment, dissociative experiences, and psychotic symptoms in the clinical population. Thus, to provide appropriate interventions, patients with schizophrenia spectrum and other psychotic disorders were asked about a wide range of possible adverse childhood experiences and dissociative experiences. Nevertheless, further studies using prospective or longitudinal designs need to be carried out to realize the differential contribution of various forms of childhood maltreatment and their potential interactions, more precisely.
Topics: Child; Child Abuse; Cross-Sectional Studies; Dissociative Disorders; Humans; Iran; Prospective Studies; Psychotic Disorders; Sex Offenses; Surveys and Questionnaires
PubMed: 34024281
DOI: 10.1186/s12888-021-03290-3 -
Clinical Psychology Review Aug 2009This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex... (Review)
Review
This paper reviews studies that have examined associations between unusual sleep experiences (including nightmares, vivid dreaming, narcolepsy symptoms, and complex nighttime behaviors) and dissociation and schizotypy. Using correlational studies and structural analyses, evidence is provided that unusual sleep experiences, dissociation, and schizotypy belong to a common domain. It is demonstrated that unusual sleep experiences show specificity to dissociation and schizotypy compared to other daytime symptoms (e.g., anxiety, depression, substance use) and other sleep disturbances (e.g., insomnia, lassitude/fatigue). The paper also outlines the methodological limitations of the existing evidence and makes suggestions for future research. Finally, three models for the overlap of daytime and nighttime symptoms are reviewed, including biological abnormalities, trauma, and personality traits. Although further research is needed, it is suggested that daytime and nighttime symptoms result from problems with sleep-wake state boundaries, which may be precipitated by stress or trauma. In addition, association between daytime and nighttime symptoms can be attributed to the higher order personality trait of Oddity.
Topics: Dissociative Disorders; Dreams; Factor Analysis, Statistical; Humans; Personality; Schizotypal Personality Disorder; Sleep Wake Disorders; Sleep, REM; Stress, Psychological
PubMed: 19581031
DOI: 10.1016/j.cpr.2009.06.004 -
General Hospital Psychiatry 2024Functional neurological disorder (FND) involves the presence of neurological symptoms that cannot be explained by neurological disease. FND has long been linked to... (Review)
Review
OBJECTIVE
Functional neurological disorder (FND) involves the presence of neurological symptoms that cannot be explained by neurological disease. FND has long been linked to hypnosis and suggestion, both of which have been used as treatments. Given ongoing interest, this review examined evidence for the efficacy of hypnosis and suggestion as treatment interventions for FND.
METHOD
A systematic search of bibliographic databases was conducted to identify group studies published over the last hundred years. No restrictions were placed on study design, language, or clinical setting. Two reviewers independently assessed papers for inclusion, extracted data, and rated study quality.
RESULTS
The search identified 35 studies, including 5 randomised controlled trials, 2 non-randomised trials, and 28 pre-post studies. Of 1584 patients receiving either intervention, 1379 (87%) showed significant improvements, including many who demonstrated resolution of their symptoms in the short-term. Given the heterogeneity of interventions and limitations in study quality overall, more formal quantitative synthesis was not possible.
CONCLUSIONS
The findings highlight longstanding and ongoing interest in using hypnosis and suggestion as interventions for FND. While the findings appear promising, limitations in the evidence base, reflecting limitations in FND research more broadly, prevent definitive recommendations. Further research seems warranted given these supportive findings.
Topics: Humans; Conversion Disorder; Dissociative Disorders; Hypnosis; Nervous System Diseases
PubMed: 38154334
DOI: 10.1016/j.genhosppsych.2023.12.006 -
Epilepsia Nov 2019We aimed to characterize the demographics of adults with dissociative (nonepileptic) seizures, placing emphasis on distribution of age at onset, male:female ratio,...
OBJECTIVE
We aimed to characterize the demographics of adults with dissociative (nonepileptic) seizures, placing emphasis on distribution of age at onset, male:female ratio, levels of deprivation, and dissociative seizure semiology.
METHODS
We collected demographic and clinical data from 698 adults with dissociative seizures recruited to the screening phase of the CODES (Cognitive Behavioural Therapy vs Standardised Medical Care for Adults With Dissociative Non-Epileptic Seizures) trial from 27 neurology/specialist epilepsy clinics in the UK. We described the cohort in terms of age, age at onset of dissociative seizures, duration of seizure disorder, level of socioeconomic deprivation, and other social and clinical demographic characteristics and their associations.
RESULTS
In what is, to date, the largest study of adults with dissociative seizures, the overall modal age at dissociative seizure onset was 19 years; median age at onset was 28 years. Although 74% of the sample was female, importantly the male:female ratio varied with age at onset, with 77% of female but only 59% of male participants developing dissociative seizures by the age of 40 years. The frequency of self-reported previous epilepsy was 27%; nearly half of these epilepsy diagnoses were retrospectively considered erroneous by clinicians. Patients with predominantly hyperkinetic dissociative seizures had a shorter disorder duration prior to diagnosis in this study than patients with hypokinetic seizures (P < .001); dissociative seizure type was not associated with gender. Predominantly hyperkinetic seizures were most commonly seen in patients with symptom onset in their late teens. Thirty percent of the sample reported taking antiepileptic drugs; this was more common in men. More than 50% of the sample lived in areas characterized by the highest levels of deprivation, and more than two-thirds were unemployed.
SIGNIFICANCE
Females with dissociative seizures were more common at all ages, whereas the proportion of males increased with age at onset. This disorder was associated with socioeconomic deprivation. Those with hypokinetic dissociative seizures may be at risk for delayed diagnosis and treatment.
Topics: Adult; Cohort Studies; Dissociative Disorders; Electroencephalography; Female; Humans; Male; Middle Aged; Retrospective Studies; Seizures; United Kingdom; Young Adult
PubMed: 31608436
DOI: 10.1111/epi.16350 -
Journal of Trauma & Dissociation : the... 2019The purpose of this study was to explore relationships between maltreatment, posttraumatic stress disorder, and the dissociative subtype of posttraumatic stress disorder...
The purpose of this study was to explore relationships between maltreatment, posttraumatic stress disorder, and the dissociative subtype of posttraumatic stress disorder among adolescents. This descriptive study used secondary data from the National Child Traumatic Stress Network Core Data Set. A clinical sample of adolescents exposed to potentially traumatizing events ages 12 to 16 was selected (N = 3081) to explore associations between trauma history characteristics, sociodemographic factors, posttraumatic stress disorder, and the dissociative subtype of PTSD which includes depersonalization and derealization. More than half of adolescents who met criteria for posttraumatic stress disorder also met criteria for the posttraumatic stress disorder dissociative subtype with significant depersonalization/derealization symptoms. No particular maltreatment type was associated with increased odds of posttraumatic stress disorder, with or without the dissociative subtype. All posttraumatic stress disorder-affected adolescents, with or without the dissociative subtype, experienced more overall potentially traumatizing events and maltreatment events than those without a posttraumatic stress disorder diagnosis. Girls and adolescents in residential treatment were more likely to have posttraumatic stress disorder with the dissociative subtype. This study provides evidence about the dissociative subtype of posttraumatic stress disorder among adolescents and provides new directions for research on trauma and dissociation. Future research studies should explore the co-occurrence of posttraumatic stress disorder and dissociation with broader range of dissociative symptoms than only depersonalization/derealization to further understand how to diagnose and treat traumatic stress disorders among adolescents.
Topics: Adolescent; Child; Child Abuse; Depersonalization; Dissociative Disorders; Female; Humans; Male; Psychiatric Status Rating Scales; Psychology, Adolescent; Stress Disorders, Post-Traumatic; United States
PubMed: 30714854
DOI: 10.1080/15299732.2019.1572043