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Journal of Affective Disorders Sep 2023Patients with Post-traumatic stress disorder (PTSD) exposed to traumatic reminders show hyperreactivity in brain areas (e.g., amygdala) belonging or related to the... (Meta-Analysis)
Meta-Analysis Review
Patients with Post-traumatic stress disorder (PTSD) exposed to traumatic reminders show hyperreactivity in brain areas (e.g., amygdala) belonging or related to the Innate Alarm System (IAS), allowing the rapid processing of salient stimuli. Evidence that IAS is activated by subliminal trauma-reminders could shed a new light on the factors precipitating and perpetuating PTSD symptomatology. Thus, we systematically reviewed studies investigating neuroimaging correlates of subliminal stimulation in PTSD. Twenty-three studies were selected from the MEDLINE and Scopus® databases for a qualitative synthesis, 5 of which allowed a further meta-analysis of fMRI data. The intensity of IAS responses to subliminal trauma-related reminders ranged from a minimum in healthy controls to a maximum in the PTSD patients with the most severe (e.g., dissociative) symptoms or the least responsiveness to treatment. Comparisons with other disorders (e.g., phobias) revealed contrasting results. Our findings demonstrate the hyperactivation of areas belonging or related to IAS in response to unconscious threats that should be integrated in diagnostic as well as in therapeutic protocols.
Topics: Humans; Stress Disorders, Post-Traumatic; Subliminal Stimulation; Brain; Amygdala; Brain Mapping; Magnetic Resonance Imaging
PubMed: 37236272
DOI: 10.1016/j.jad.2023.05.047 -
Consciousness and Cognition Mar 2023Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a... (Review)
Review
BACKGROUND
Strange face illusions describe a range of visual apparitions that occur when an observer gazes at their image reflected in a mirror or at another person's face in a dimly lit room. The illusory effects range from mild alterations in colour, or contrast, to the perception of distorted facial features, or new strange faces.The current review critically evaluates studies investigating strange face illusions, their methodological quality, and existing interpretations.
METHOD
Searches conducted using Scopus, PubMed, ScienceDirect and the grey literature until June 2022 identified 21 studies (N = 1,132; healthy participants n = 1,042; clinical participants n = 90) meeting the inclusion criteria (i.e., providing new empirical evidence relating to strange face illusions). The total sample had a mean age of 28.3 years (SD = 10.31) and two thirds (67 %) of participants tested to date are female. Results are reported using the Preferred Reporting Items for Systematic Reviews and meta-Analyses (PRISMA) guidelines. The review was preregistered at the Open Science Framework (OSF: https://osf.io/ek48d).
RESULTS
Pooling data across studies, illusory new strange faces are experienced by 58% (95%CI 48 to 68) of nonclinical participants. Study quality as assessed by the Appraisal Tool for Cross-Sectional Studies (AXIS) revealed that 3/21 (14.28%) studies were rated as high, 9/21 (42.86%) as moderate and 9/21 (42.86%) as low quality. Whilst the items relating specifically to reporting quality scored quite highly, those relating to study design and possible biases were lower and more variable. Overall, study quality accounted for 87% of the variance in reporting rates for strange faces, with higher quality being associated with lower illusion rates. The prevalence of illusions was also significantly greater in samples that were older, had higher proportions of female participants and for the interpersonal dyad (IGDT) compared to the mirror gaze paradigm (MGT). The moderating impact of study quality persisted in a multiple meta-regression involving participant age, paradigm type (IGDT vs MGT) and level of feature distortion. Our review point to the importance of reduced light levels, face stimuli and prolonged eye fixation for strange face illusions to emerge.
CONCLUSION
Strange face illusions reliably occur in both mirror-gazing and interpersonal gazing dyad paradigms. Further research of higher quality is required to establish the prevalence and particularly, the mechanisms underpinning strange face illusions.
Topics: Humans; Female; Adult; Male; Illusions; Cross-Sectional Studies; Face; Fixation, Ocular; Dissociative Disorders
PubMed: 36764163
DOI: 10.1016/j.concog.2023.103480 -
Therapeutic Advances in... 2023The therapeutic potential of subanesthetic doses of ketamine appears promising in unipolar depression; however, its effectiveness in treating bipolar depression (BD)...
BACKGROUND
The therapeutic potential of subanesthetic doses of ketamine appears promising in unipolar depression; however, its effectiveness in treating bipolar depression (BD) remains uncertain.
OBJECTIVE
This systematic review aimed to summarize findings on the use of ketamine for the treatment of BD by assessing its efficacy, safety, and tolerability.
DESIGN
Systematic review.
METHODS
We conducted a systematic review of studies that investigated the use of ketamine for adults with BD. We searched PubMed and Embase for relevant randomized-controlled trials, open-label trials, and retrospective chart analyses published from inception to 13 March 2023.
RESULTS
Eight studies were identified [pooled = 235; mean (SD) age: 45.55 (5.54)]. All participants who received intravenous (IV) ketamine were administered a dose of 0.5-0.75 mg/kg as an adjunctive treatment to a mood-stabilizing agent, whereas participants who received esketamine were administered a dosage ranging from 28 to 84 mg. Flexible dosing was used in real-world analyses. A total of 48% of participants receiving ketamine achieved a response (defined as ⩾50% reduction in baseline depression severity), whereas only 5% achieved a response with a placebo. Real-world studies demonstrated lower rates of response (30%) compared to the average across clinical trials (63%). Reductions in suicidal ideation were noted in some studies, although not all findings were statistically significant. Ketamine and esketamine were well tolerated in most participants; however, six participants (2% of the overall sample pool, 5 receiving ketamine) developed hypomanic/manic symptoms after infusions. Significant dissociative symptoms were observed at the 40-min mark in some trials.
CONCLUSION
Preliminary evidence suggests IV ketamine as being safe and effective for the treatment of BD. Future studies should focus on investigating the effects of repeated acute and maintenance infusions using a randomized study design.
PubMed: 37771417
DOI: 10.1177/20451253231202723 -
Journal of Psychiatric Research Sep 2020There is currently no general agreement on how to best conceptualize dissociative symptoms and whether they share similar neural underpinnings across dissociative... (Review)
Review
INTRODUCTION
There is currently no general agreement on how to best conceptualize dissociative symptoms and whether they share similar neural underpinnings across dissociative disorders. Neuroimaging data could help elucidate these questions.
OBJECTIVES
The objective of this review is to summarize empirical evidence for neural aberrations observed in patients suffering from dissociative symptoms.
METHODS
A systematic literature review was conducted including patient cohorts diagnosed with primary dissociative disorders, post-traumatic stress disorder (PTSD), or borderline personality disorder.
RESULTS
Results from MRI studies reporting structural (gray matter and white matter) and functional (during resting-state and task-related activation) brain aberrations were extracted and integrated. In total, 33 articles were included of which 10 pertained to voxel-based morphology, 2 to diffusion tensor imaging, 10 to resting-state fMRI, and 11 to task-related fMRI. Overall findings indicated aberrations spread across diverse brain regions, especially in the temporal and frontal cortices. Patients with dissociative identity disorder and with dissociative PTSD showed more overlap in brain activation than each group showed with depersonalization/derealization disorder.
CONCLUSION
In conjunction, the results indicate that dissociative processing cannot be localized to a few distinctive brain regions but rather corresponds to differential neural signatures depending on the symptom constellation.
Topics: Brain; Diffusion Tensor Imaging; Dissociative Disorders; Gray Matter; Humans; Magnetic Resonance Imaging; Stress Disorders, Post-Traumatic
PubMed: 32480060
DOI: 10.1016/j.jpsychires.2020.05.006 -
The Australian and New Zealand Journal... Oct 2022Borderline Personality Disorder (BPD) is frequently complicated by the presence of dissociative symptoms. Pathological dissociation is linked with earlier and more... (Review)
Review
BACKGROUND
Borderline Personality Disorder (BPD) is frequently complicated by the presence of dissociative symptoms. Pathological dissociation is linked with earlier and more severe trauma exposure, emotional dysregulation and worse treatment outcomes in Posttraumatic Stress Disorder and Dissociative Disorders, with implications for BPD.
OBJECTIVE
A systematic scoping review was conducted to assess the extent of current literature regarding the impact of dissociation on BPD and to identify knowledge gaps.
METHODS
Four electronic databases (MEDLINE, APA PsycINFO, EMBASE, CINAHL Plus) were searched, and English peer-reviewed studies with adults with BPD were included, following Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) extension for scoping reviews (PRISMA-ScR) 2018 guidelines.
RESULTS
Most of the 70 included studies were observational (98%) with first authors from Germany (59%). Overall, dissociation was associated with increased BPD symptom severity, self-harm and reduced psychotherapy treatment response; findings regarding suicide risk were mixed. Dissociation was associated with working memory and cognitive deficits, decreased pain perception, altered body ownership, no substance abuse or the abuse of sedative substances, increased fantasy proneness, personality fragmentation, fearful attachment, dream anxiety, perceived stress and altered stress responses, increased cumulative body mass index, decreased water consumption, several neurological correlates and changes in gene expression.
CONCLUSION
BPD with significant dissociative symptoms may constitute a more severe and at-risk subgroup of BPD patients. However, there are significant research gaps and methodological issues in the area, including the possibility of unrecognized Dissociative Disorders in BPD study populations confounding results. Further studies are needed to better understand the impact of dissociation on BPD course and treatment, and to clarify the most appropriate assessment tools for clinical practice. In addition, interventional studies are needed to develop dissociation-specific BPD treatments to determine whether targeting dissociation in BPD can improve treatment outcomes.
Topics: Adult; Borderline Personality Disorder; Dissociative Disorders; Humans; Hypnotics and Sedatives; Psychotherapy; Self-Injurious Behavior
PubMed: 35152771
DOI: 10.1177/00048674221077029 -
Frontiers in Pain Research (Lausanne,... 2022Pain and depression frequently co-occur. Due to its antidepressant and analgesic properties, ketamine has been used for the management of treatment-resistant depression... (Review)
Review
Pain and depression frequently co-occur. Due to its antidepressant and analgesic properties, ketamine has been used for the management of treatment-resistant depression and pain. This systematic review examined the literature on the efficacy of sub-anesthetic doses of ketamine in individuals experiencing comorbid depression and chronic pain (CDCP), as well as comorbid depression and acute pain (CDAP). A secondary objective was to provide an assessment of dosage, route, and adverse effects of ketamine treatment for CDCP and CDAP. A literature search was conducted on MEDLINE, PsycINFO, and Embase databases, coupled with a manual screening of the bibliography sections of included articles. In addition, registered ongoing and planned trials were searched on Clinicaltrials.gov. The end date of the search was April 9th, 2022. Included studies assessed changes in depression and pain in patients receiving at least one sub-anesthetic dose of ketamine. Assessment of quality was conducted using the GRADE checklist. Of the 7 CDCP clinical trials, 3 reported a reduction in depression and pain, 3 reported a reduction in depression or pain only, and 1 reported no improvement in either comorbidity. Among the 7 CDAP clinical trials, 4 studies found improvements in depression and pain while the remaining 3 reported improvements in only one parameter. Ten of the 12 case studies and 2 of the 3 observational studies assessing CDCP and CDAP found improvements in pain and depression scores post-treatment with effects of variable duration. The planned methodologies of the registered clinical trials are in line with those of the published research. Preliminary evidence supports the efficacy of ketamine in treating CDCP and CDAP. However, the current review identified a small number of heterogeneous studies with mixed results, preventing comprehensive conclusions. More longitudinal placebo-controlled studies are needed to identify the effects of ketamine for patients with CDCP and CDAP.
PubMed: 36353699
DOI: 10.3389/fpain.2022.1022767 -
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 -
The International Journal of... Jul 2021Ketamine appears to have a therapeutic role in certain mental disorders, most notably unipolar major depressive disorder. However, its efficacy in bipolar depression is...
BACKGROUND
Ketamine appears to have a therapeutic role in certain mental disorders, most notably unipolar major depressive disorder. However, its efficacy in bipolar depression is less clear. This study aimed to assess the efficacy and tolerability of ketamine for bipolar depression.
METHODS
We conducted a systematic review of experimental studies using ketamine for the treatment of bipolar depression. We searched PubMed, MEDLINE, Embase, PsycINFO, and the Cochrane Central Register for relevant studies published since each database's inception. We synthesized evidence regarding efficacy (improvement in depression rating scores) and tolerability (adverse events, dissociation, dropouts) across studies.
RESULTS
We identified 6 studies, with 135 participants (53% female; 44.7 years; standard deviation, 11.7 years). All studies used 0.5 mg/kg of add-on intravenous racemic ketamine, with the number of doses ranging from 1 to 6; all participants continued a mood-stabilizing agent. The overall proportion achieving a response (defined as those having a reduction in their baseline depression severity of at least 50%) was 61% for those receiving ketamine and 5% for those receiving a placebo. The overall response rates varied from 52% to 80% across studies. Ketamine was reasonably well tolerated; however, 2 participants (1 receiving ketamine and 1 receiving placebo) developed manic symptoms. Some participants developed significant dissociative symptoms at the 40-minute mark following ketamine infusion in 2 trials.
CONCLUSIONS
There is some preliminary evidence supporting use of intravenous racemic ketamine to treat adults with bipolar depression. There is a need for additional studies exploring longer-term outcomes and alterative formulations of ketamine.
Topics: Bipolar Disorder; Excitatory Amino Acid Antagonists; Humans; Ketamine
PubMed: 33929489
DOI: 10.1093/ijnp/pyab023 -
Epilepsy & Behavior : E&B Mar 2024The term 'functional/dissociative seizures (FDS)' refers to a paroxysmal, transient clinical manifestation that may include motor, sensory, vegetative, psychological and... (Review)
Review
INTRODUCTION
The term 'functional/dissociative seizures (FDS)' refers to a paroxysmal, transient clinical manifestation that may include motor, sensory, vegetative, psychological and cognitive signs, similar to the manifestations observed in epileptic seizures. In recent years, there has been an increase of literature in the field of brain imaging research on functional neurological disorders and, more specifically, on FDS. However, most of the studies have been carried out on limited samples. We propose an update of this review work by performing a systematic review of studies performed since 2017 in the field of neuroimaging in patients with FDS.
METHODS
We conducted a systematic review of the literature using the PRISMA methodology and reproduced most of the methodological elements of the latest systematic literature review.
RESULTS
Our work over the last five years has identified 14 articles. It is still difficult to isolate a distinct structure or network specifically involved in the mechanism of FDS. However, certain structures are recurrently involved in imaging studies, notably the amygdala, the orbitofrontal cortex, and the anterior cingulate cortex.
CONCLUSION
The contribution of neuroimaging may allow a more precise explanation of the disorder for patients, avoiding the stigma frequently associated with this diagnosis. as with other 'conversion' phenomena which have traditionally been considered only as 'medically unexplained'. In the longer term and beyond a better understanding of the physiopathology of the disorder, the challenge of this neuroimaging work would be to identify specific imaging biomarkers for a diagnosis of FDS.
Topics: Humans; Psychogenic Nonepileptic Seizures; Conversion Disorder; Dissociative Disorders; Seizures; Epilepsy
PubMed: 38281393
DOI: 10.1016/j.yebeh.2024.109654 -
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