It's about time: mitigating cancer-related cognitive impairments through findings from computational models of the Wisconsin Card Sorting Task.

BACKGROUND: Many cancer survivors experience cancer-related cognitive impairment (CRCI), often with significant negative consequences across various life domains. Emerging evidence suggests that allowing additional time to process information before acting may be a useful strategy for those with CRCI to mitigate some of its impacts. The Wisconsin Card Sorting Task (WCST), a measure of general cognition, has shown that for some cancer survivors, longer task completion time facilitates similar task performance outcomes to control populations concerning perseveration errors; a key performance metric of the WCST. However, assessing if this strategy may be useful, as well as determining for whom it may be useful, with regard to strengths and weaknesses among select cognitive domains, is challenging due to factors such as the problem of task impurity. Accordingly, this study provides an initial computational and experimental assessment of whether additional time to process information before acting is a useful strategy for those with CRCI. METHODS: We simulated individual cognitive differences observed in humans by varying contributions of executive functioning components (updating, shifting, inhibition) to yield 48 distinct computational models of the WCST. Our main manipulation was then to provide these models with more or less time (at three levels of 20, 40 and 60 cycles) before models executed an action to sort a given card. We compared the number of perseveration errors on the WCST produced by the computational models. Additionally, we determined models that simulated the performance of cancer survivors on the WCST by comparing the number of perseveration errors produced by the models to human data. RESULTS: Additional processing time resulted in the models producing significantly fewer perseveration errors, supporting our hypothesis. In addition, 8 unique models simulated the performance of cancer survivors on the WCST. Additional time appeared to have a positive influence on performance primarily by mitigating the impacts of severe inhibition impairments. For more severe global executive function impairments, a substantial amount of additional time was required to mitigate the impacts of the impairments. For the most severe impairments, additional time was unable to adequately mitigate the impact on performance. CONCLUSION: Additional processing time may be a useful strategy to rectify perseveration errors among cancer survivors with CRCI. Our findings have implications for the development of practical strategies, such as workload and deadline management in occupational settings, which may mitigate the negative effects of CRCI.

Relative associations of behavioral and physiological risks for cardiometabolic disease with cognition in bipolar disorder during mid and later-life: findings from the UK biobank.

BACKGROUND: Cardiometabolic disease risk factors are disproportionately prevalent in bipolar disorder (BD) and are associated with cognitive impairment. It is, however, unknown which health risk factors for cardiometabolic disease are relevant to cognition in BD. This study aimed to identify the cardiometabolic disease risk factors that are the most important correlates of cognitive impairment in BD; and to examine whether the nature of the relationships vary between mid and later life. METHODS: Data from the UK Biobank were available for 966 participants with BD, aged between 40 and 69 years. Individual cardiometabolic disease risk factors were initially regressed onto a global cognition score in separate models for the following risk factor domains; (1) health risk behaviors (physical activity, sedentary behavior, smoking, and sleep) and (2) physiological risk factors, stratified into (2a) anthropometric and clinical risk (handgrip strength, body composition, and blood pressure), and (2b) cardiometabolic disease risk biomarkers (CRP, lipid profile, and HbA1c). A final combined multivariate regression model for global cognition was then fitted, including only the predictor variables that were significantly associated with cognition in the previous models. RESULTS: In the final combined model, lower mentally active and higher passive sedentary behavior, higher levels of physical activity, inadequate sleep duration, higher systolic and lower diastolic blood pressure, and lower handgrip strength were associated with worse global cognition. CONCLUSIONS: Health risk behaviors, as well as blood pressure and muscular strength, are associated with cognitive function in BD, whereas other traditional physiological cardiometabolic disease risk factors are not.

Cancer-related cognitive impairment as a key contributor to psychopathology in cancer survivors: implications for prevention, treatment and supportive care.

A significant proportion of cancer survivors will experience some form of mental health compromise across domains including mood, anxiety, psychosis, eating disorders, and substance use. This psychopathology within cancer survivors is related to a range of negative outcomes and can also have a substantial negative impact on quality of life. Along with psychopathology, cognitive impairments are also commonly experienced, resulting in deficits in memory, reasoning, decision-making, speed of processing, and concentration, collectively referred to as cancer-related cognitive impairment (CRCI). Within the non-oncology literature, cognitive deficits are consistently demonstrated to be a key transdiagnostic aetiological feature of psychopathology, functionally contributing to the development and perpetuation of symptoms. Whilst there is an acknowledgement of the role mental health concerns might play in the development of and perception of CRCI, there has been limited acknowledgement and research exploring the potential for CRCI to functionally contribute toward the development of transdiagnostic psychopathology in cancer survivors beyond simply psychosocial distress. Given the theoretical and empirical evidence suggesting cognitive deficits to be an aetiological factor in psychopathology, we provide a rationale for the potential for CRCI to be a factor in the development and perpetuation of transdiagnostic psychopathology in cancer survivors. This potential functional association has significant implications for risk identification, prevention, treatment, and supportive cancer care approaches regarding psychopathology in cancer survivorship. We conclude by providing directions for future research in this area.

The Phenomenology of Visual and Other Nonauditory Hallucinations in Affective and Nonaffective Psychosis: A Mixed Methods Analysis.

ABSTRACT: Nonauditory hallucinations in psychosis have not received as much attention relative to voice-hearing experiences. The current paper aimed to document the characteristics of these hallucinations in affective and nonaffective psychosis. Participants were selected from a primary voice-hearing sample, who had endorsed visual, tactile, or olfactory hallucinations ( N = 55-75). A comprehensive, semistructured phenomenological interview was conducted, followed by mixed methods analysis. Visual hallucinations typically occurred daily, for a few minutes per episode, within one's direct line of sight; persons and/or animals were most commonly seen, with low controllability and mostly engendered negative affective outcomes. Tactile and olfactory hallucinations were endorsed by 46.8% and 39.0% of participants, respectively. The affective psychosis group ( n = 33) reported significantly greater awareness and lower functional impairment relative to the nonaffective psychosis group ( n = 42). Qualitative thematic analysis revealed notable themes and subthemes across each of these hallucinations modes. Further phenomenological investigations should be carried out in lesser known hallucination modalities, assisted by the development of appropriate assessment tools.

Disturbed interoception in body dysmorphic disorder: A framework for future research.

Body dysmorphic disorder is a severe psychiatric condition characterised by a preoccupation with a perceived appearance flaw or flaws that are typically not observable to others. Although significant advances in understanding the disorder have been made in the past decade, current explanations focus on cognitive, behavioural and visual perceptual disturbances that contribute to the disorder. Such a focus does not consider how perception of the internal body or interoception may be involved, despite (1) clinical observations of disturbed perception of the body in body dysmorphic disorder and (2) disturbed interoception being increasingly recognised as a transdiagnostic factor underlying a wide range of psychopathologies. In this paper, we use an existing model of hierarchical brain function and neural (predictive) processing to propose that body dysmorphic disorder involves defective interoception, with perceived appearance flaws being the result of 'interoceptive prediction errors' that cause body parts to be experienced as 'not just right'. We aim to provide a framework for interoceptive research into body dysmorphic disorder, and outline areas for future research.

Glutamatergic neurotransmission in schizophrenia: A systematic review and quantitative synthesis of proton magnetic resonance spectroscopy studies across schizophrenia spectrum disorders.

OBJECTIVE: Studies using proton magnetic resonance spectroscopy reveal substantial inconsistencies in the levels of brain glutamate, glutamine and glutamate + glutamine across schizophrenia spectrum disorders. This systematic review employs qualitative and quantitative methods to analyse the patterns and relationships between glutamatergic metabolites, schizophrenia spectrum disorders and brain regions. METHODS: A literature search was conducted using various databases with keywords including glutamate, glutamine, schizophrenia, psychosis and proton magnetic resonance spectroscopy. Inclusion criteria were limited to case-control studies that reported glutamatergic metabolite levels in adult patients with a schizophrenia spectrum disorder diagnosis - i.e. first-episode psychosis, schizophrenia, treatment-resistant schizophrenia and/or ultra-treatment-resistant schizophrenia - using proton magnetic resonance spectroscopy at 3 T or above. Pooled study data were synthesized and analysed. RESULTS: A total of 92 studies met the inclusion criteria, including 2721 healthy controls and 2822 schizophrenia spectrum disorder participants. Glu levels were higher in the basal ganglia, frontal cortex and medial prefrontal of first-episode psychosis participants, contrasting overall lower levels in schizophrenia participants. For Gln, strong differences in metabolite levels were evident in the basal ganglia, dorsolateral prefrontal cortex and frontal cortex, with first-episode psychosis showing significantly higher levels in the basal ganglia. In glutamate + glutamine, higher metabolite levels were found across schizophrenia spectrum disorder groups, particularly in the basal ganglia and dorsolateral prefrontal cortex of treatment-resistant schizophrenia participants. Significant relationships were found between metabolite levels and medication status, clinical measures and methodological variables. CONCLUSION: The review highlights abnormal glutamatergic metabolite levels throughout schizophrenia spectrum disorders and in specific brain regions. The review underscores the importance of standardized future research assessing glutamatergic metabolites using proton magnetic resonance spectroscopy due to considerable literature heterogeneity.

Examining the relationships between cognition and auditory hallucinations: A systematic review.

OBJECTIVE: Auditory hallucinations (hearing voices) have been associated with a range of altered cognitive functions, pertaining to signal detection, source-monitoring, memory, inhibition and language processes. Yet, empirical results are inconsistent. Despite this, several theoretical models of auditory hallucinations persist, alongside increasing emphasis on the utility of a multidimensional framework. Thus, clarification of current evidence across the broad scope of proposed mechanisms is warranted. METHOD: A systematic search of the Web of Science, PubMed and Scopus databases was conducted. Records were screened to confirm the use of an objective behavioural cognitive task, and valid measurement of hallucinations specific to the auditory modality. RESULTS: Auditory hallucinations were primarily associated with difficulties in perceptual decision-making (i.e. reduced sensitivity/accuracy for signal-noise discrimination; liberal responding to ambiguity), source-monitoring (i.e. self-other and temporal context confusion), working memory and language function (i.e. reduced verbal fluency). Mixed or limited support was observed for perceptual feature discrimination, imagery vividness/illusion susceptibility, source-monitoring for stimulus form and spatial context, recognition and recall memory, executive functions (e.g. attention, inhibition), emotion processing and language comprehension/hemispheric organisation. CONCLUSIONS: Findings were considered within predictive coding and self-monitoring frameworks. Of concern was the portion of studies which - despite offering auditory-hallucination-specific aims and inferences - employed modality-general measures, and/or diagnostic-based contrasts with psychologically healthy individuals. This review highlights disparities within the literature between theoretical conceptualisations of auditory hallucinations and the body of rigorous empirical evidence supporting such inferences. Future cognitive investigations, beyond the schizophrenia-spectrum, which explicitly define and measure the timeframe and sensory modality of hallucinations, are recommended.

Development of a harmonized sociodemographic and clinical questionnaire for mental health research: A Delphi-method-based consensus recommendation.

OBJECTIVE: Harmonized tools are essential for reliable data sharing and accurate identification of relevant factors in mental health research. The primary objective of this study was to create a harmonized questionnaire to collect demographic, clinical and behavioral data in diverse clinical trials in adult psychiatry. METHODS: We conducted a literature review and examined 24 questionnaires used in previously published randomized controlled trials in psychiatry, identifying a total of 27 domains previously explored. Using a Delphi-method process, a task force team comprising experts in psychiatry, epidemiology and statistics selected 15 essential domains for inclusion in the final questionnaire. RESULTS: The final selection resulted in a concise set of 22 questions. These questions cover factors such as age, sex, gender, ancestry, education, living arrangement, employment status, home location, relationship status, and history of medical and mental illness. Behavioral factors like physical activity, diet, smoking, alcohol and illicit drug use were also included, along with one question addressing family history of mental illness. Income was excluded due to high confounding and redundancy, while language was included as a measure of migration status. CONCLUSION: The recommendation and adoption of this harmonized tool for the assessment of demographic, clinical and behavioral data in mental health research can enhance data consistency and enable comparability across clinical trials.

A new network analysis model in anorexia nervosa patients based on self-reported eating disorder symptoms, psychological distress, and cognitive flexibility.

OBJECTIVES: Cognitive flexibility and psychological distress, such as depression and anxiety, have been implicated in the aetiology of Anorexia Nervosa (AN). Despite the known associations between eating disorder (ED) symptoms, depression, anxiety, and cognitive flexibility, the specific pathways that connect these constructs are unclear. We therefore used network analysis to examine the relationship between these symptoms in an AN sample. METHODS: One hundred and ninety-three treatment-seeking individuals diagnosed with AN (95.6% female, M = 26.89 [SD = 9.45] years old) completed self-report measures assessing depression, anxiety, cognitive flexibility, and ED symptoms. To determine each symptom's influence in the network, we calculated the expected influence. RESULTS: The two relationships with the greatest edges were those between (1) weight/shape concerns and eating/dietary restraint and (2) weight/shape concerns and psychological distress (a measure that combined depression and anxiety). Cognitive flexibility was not connected to weight/shape concerns but had negative partial associations with eating concerns/dietary restraint and psychological distress. There was also a slight, non-zero connection between eating concerns/dietary restraint and psychological distress. CONCLUSIONS: The findings underscore the importance of weight/shape, eating/dietary concerns, and psychological distress in the AN network and suggest that addressing cognitive flexibility may be a useful target for eating concerns/dietary restraint and psychological distress. Future studies assessing the longitudinal course of psychopathology within the AN network structure may help in identifying whether specific symptoms function as risk factors or maintaining factors for this co-occurrence.

A hierarchy of visual processing deficits in body dysmorphic disorder: a conceptual review and empirical investigation.

OBJECTIVE: Abnormal visual processing has been proposed as a mechanism underlying excessive focus on minor appearance flaws in body dysmorphic disorder (BDD). Existing BDD research has not differentiated the various stages of face processing (featural, first-order configural, holistic and second-order configural) that are required for higher-order processes such as emotion recognition. This study investigated a hierarchical visual processing model to examine the nature of abnormalities in face processing in BDD. METHOD: Thirty BDD participants and 27 healthy controls completed the Navon task, a featural and configural face processing task and a facial emotion labelling task. RESULTS: BDD participants performed similarly to controls when processing global and local non-face stimuli on the Navon task, when detecting subtle changes in the features and spacing of a target face, and when labelling emotional faces. However, BDD participants displayed poorer performance when viewing inverted faces, indicating difficulties in configural processing. CONCLUSIONS: The findings only partially support prior work. However, synthesis of results with previous findings indicates that heterogenous task methodologies may contribute to inconsistent findings. Recommendations are provided regarding the task parameters that appear most sensitive to abnormalities in BDD.

Exploring the cognitive profiles related to unimodal auditory versus multisensory hallucinations in schizophrenia-spectrum disorders.

INTRODUCTION: Hallucinations can be experienced across multiple sensory modalities, but psychiatric studies investigating the cognitive mechanisms of hallucinations have been somewhat restricted to the auditory domain. This study explored the cognitive profiles of individuals experiencing multisensory hallucinations (MH) in schizophrenia-spectrum disorders (SSD) and compared these to those experiencing unimodal auditory hallucinations (AH) or no hallucinations (NH). METHODS: Participants included SSD patients (n = 119) stratified by current hallucination status (NH, AH, MH) and nonclinical controls (NCs; n = 113). Group performance was compared across several cognitive domains: speed of processing, attention, working memory, verbal learning, visual learning, reasoning and problem-solving, social cognition, and inhibition. RESULTS: The clinical groups performed worse than NCs but differences between the clinical groups were not evident across most cognitive domains. Exploratory analyses revealed that the MH group was more impaired on the visual learning task compared to the NH (but not AH) group. CONCLUSIONS: Preliminary results suggest that impaired visual learning may be related to MH. This could be attributed to the presence of visual hallucinations (VH), or greater psychopathology, in this group. However, replication is needed, as well as the investigation of other potential cognitive mechanisms of MH.

Clinical outcomes of deep brain stimulation for obsessive-compulsive disorder: Insight as a predictor of symptom changes.

AIM: Deep brain stimulation (DBS) is a safe and effective treatment option for people with refractory obsessive-compulsive disorder (OCD). Yet our understanding of predictors of response and prognostic factors remains rudimentary, and long-term comprehensive follow-ups are lacking. We aim to investigate the efficacy of DBS therapy for OCD patients, and predictors of clinical response. METHODS: Eight OCD participants underwent DBS stimulation of the nucleus accumbens (NAc) in an open-label longitudinal trial, duration of follow-up varied between 9 months and 7 years. Post-operative care involved comprehensive fine tuning of stimulation parameters and adjunct multidisciplinary therapy. RESULTS: Six participants achieved clinical response (35% improvement in obsessions and compulsions on the Yale Brown Obsessive Compulsive Scale (YBOCS)) within 6-9 weeks, response was maintained at last follow up. On average, the YBOCS improved by 45% at last follow up. Mixed linear modeling elucidated directionality of symptom changes: insight into symptoms strongly predicted (P = 0.008) changes in symptom severity during DBS therapy, likely driven by initial changes in depression and anxiety. Precise localization of DBS leads demonstrated that responders most often had their leads (and active contacts) placed dorsal compared to non-responders, relative to the Nac. CONCLUSION: The clinical efficacy of DBS for OCD is demonstrated, and mediators of changes in symptoms are proposed. The symptom improvements within this cohort should be seen within the context of the adjunct psychological and biopsychosocial care that implemented a shared decision-making approach, with flexible iterative DBS programming. Further research should explore the utility of insight as a clinical correlate of response. The trial was prospectively registered with the ANZCTR (ACTRN12612001142820).

Intersections of phenomenology, voice beliefs and distress in bipolar disorder: a comparison with schizophrenia.

BACKGROUND: Auditory verbal hallucinations (AVH), or voice-hearing, can be a prominent symptom during fluctuating mood states in bipolar disorder (BD). AIMS: The current study aimed to: (i) compare AVH-related distress in BD relative to schizophrenia (SCZ), (ii) examine correlations between phenomenology and voice beliefs across each group, and (iii) explore how voice beliefs may uniquely contribute to distress in BD and SCZ. METHOD: Participants were recruited from two international sites in Australia (BD=31; SCZ=50) and the UK (BD=17). Basic demographic-clinical information was collected, and mood symptoms were assessed. To document AVH characteristics, a 4-factor model of the Psychotic Symptoms Rating Scale and the Beliefs about Voices Questionnaire-Revised were used. Statistical analyses consisted of group-wise comparisons, Pearson's correlations and multiple hierarchical regressions. RESULTS: It was found that AVH-related distress was not significantly higher in BD than SCZ, but those with BD made significantly more internal attributions for their voices. In the BD group, AVH-related distress was significantly positively correlated with malevolence, omnipotence and resistance, However, only resistance, alongside mania and depressive symptoms, significantly contributed to AVH-related distress in BD. DISCUSSION: Our findings have several clinical implications, including identification of voice resistance as a potential therapeutic target to prioritise in BD. Factoring in the influence of mood symptoms on AVH-related distress as well as adopting more acceptance-oriented therapies may also be of benefit.

The Cosmetic Readiness Questionnaire (CRQ): Validation of a Pre-Operative Psychological Screening Tool for Aesthetic Procedures.

BACKGROUND: Several psychological risk factors are associated with patient dissatisfaction with aesthetic procedures, such as body dysmorphic disorder (BDD), unmanaged mental health concerns or unrealistic expectations. Identifying these risks via preoperative screening may protect patients from adverse psychological outcomes and provide reputational or legal protection for practitioners. OBJECTIVES: This study aimed to further develop and validate the Cosmetic Readiness Questionnaire (CRQ), a comprehensive psychological screening tool to assess patient suitability for surgical and non-surgical aesthetic procedures. METHODS: The CRQ was validated across two studies in clinical contexts, examining structural and construct validity in a sample of 8031 individuals who completed the CRQ as part of routine clinical care. In a further sample (n = 574), criterion validity was explored through the relationship between the CRQ and dissatisfaction with past aesthetic treatments. Risk category cut-off scores were developed. RESULTS: Results supported the reliability and validity of a five-factor CRQ which measures Body Dysmorphia, Psychological Distress, Self-Criticism, Unrealistic Expectations and Lack of Openness. High scorers on the CRQ were 78% more likely to report dissatisfaction with a past cosmetic procedure than low scorers. CONCLUSIONS: The CRQ is a comprehensive and valid screening measure to identify patients who may require further psychological assessment or additional support prior to aesthetic treatment. Instructions are provided on how to implement the CRQ in clinical practice.

Development of a Pre-Operative Psychological Screening Tool: Piloting the Cosmetic Readiness Questionnaire (Pilot-CRQ).

BACKGROUND: Patients with psychological risk factors, such as body dysmorphic disorder (BDD), and unmanaged mental health concerns are considered higher risk of dissatisfaction with aesthetic procedures. Identifying these risks before a procedure may decrease the chance of adverse outcomes for patients and practitioners. OBJECTIVES: This study aimed to develop a comprehensive psychological screening tool to assess patient's psychological suitability for surgical and non-surgical aesthetic procedures. METHODS: Items for the Pilot-Cosmetic Readiness Questionnaire (CRQ) were developed by psychologists (n = 3) and then reviewed by plastic surgeons (n = 2) and non-surgical cosmetic doctors (n = 3). Patient interviews (n = 15) and piloting of the questionnaire (n = 69) provide data to examine the scale's initial psychometric properties. RESULTS: Results supported the reliability and validity of the Pilot-CRQ's subscales of Body Dysmorphia, Psychological Distress, Self-Criticism, Perfectionism, and Lack of Openness. 'Lack of Openness' is a validity scale which examines the degree that respondents may be underreporting symptoms. The CRQ predicted individuals with a BDD diagnosis as rated by a blinded expert clinical psychologist, with high sensitivity and specificity. CONCLUSIONS: These results provide support for the Pilot-CRQ in identifying people with BDD and psychological factors related to aesthetic treatment outcomes and provide a strong basis for using the CRQ in clinical contexts and in future research.

Psychiatric comorbidity and severity in anorexia nervosa: a comparative study of the DSM-5, the ICD-11, and overvaluation of Weight/Shape severity ratings.

This study assessed the rate of a.) the total and b.) specific psychiatric comorbidities among the three severity ratings for Anorexia Nervosa (AN): DSM-5, ICD-11 and overvaluation of weight and shape (OWS). The sample comprised 312 treatment-seeking patients with AN (mean age = 26.9). Weight and height were taken at intake to calculate BMI, the foundation for the DSM-5 and ICD-11 severity indices. The EDE-Q was used to assess OWS, and the Mini International Neuropsychiatric Interview was conducted to assess psychiatric comorbidities. For the DSM-5, the mild severity group showed a higher total number of psychiatric comorbidities, especially for panic, social anxiety, generalised anxiety, and post-traumatic stress disorders compared to the severe and extremely severe groups. ICD-11 and OWS severity groups did not significantly differ in total comorbidities, except for major depressive disorder and obsessive-compulsive disorders being more prevalent in the "significantly low BMI" ICD-11 group. The high OWS group displayed a notably higher rate of major depressive disorder than the low OWS group. The study underscores inconsistent patterns across the three severity systems, emphasising the need to recognise the current limitations of the assessed severity classification systems in AN assessment and guiding treatment.

Brain Morphological Characteristics of Cognitive Subgroups of Schizophrenia-Spectrum Disorders and Bipolar Disorder: A Systematic Review with Narrative Synthesis.

Despite a growing body of research, there is yet to be a cohesive synthesis of studies examining differences in brain morphology according to patterns of cognitive function among both schizophrenia-spectrum disorder (SSD) and bipolar disorder (BD) individuals. We aimed to provide a systematic overview of the morphological differences-inclusive of grey and white matter volume, cortical thickness, and cortical surface area-between cognitive subgroups of these disorders and healthy controls, and between cognitive subgroups themselves. An initial search of PubMed and Scopus databases resulted in 1486 articles of which 20 met inclusion criteria and were reviewed in detail. The findings of this review do not provide strong evidence that cognitive subgroups of SSD or BD map to unique patterns of brain morphology. There is preliminary evidence to suggest that reductions in cortical thickness may be more strongly associated with cognitive impairment, whilst volumetric deficits may be largely tied to the presence of disease.

Default Mode Network Modulation by Psychedelics: A Systematic Review.

Psychedelics are a unique class of drug that commonly produce vivid hallucinations as well as profound psychological and mystical experiences. A grouping of interconnected brain regions characterized by increased temporal coherence at rest have been termed the Default Mode Network (DMN). The DMN has been the focus of numerous studies assessing its role in self-referencing, mind wandering, and autobiographical memories. Altered connectivity in the DMN has been associated with a range of neuropsychiatric conditions such as depression, anxiety, post-traumatic stress disorder, attention deficit hyperactive disorder, schizophrenia, and obsessive-compulsive disorder. To date, several studies have investigated how psychedelics modulate this network, but no comprehensive review, to our knowledge, has critically evaluated how major classical psychedelic agents-lysergic acid diethylamide, psilocybin, and ayahuasca-modulate the DMN. Here we present a systematic review of the knowledge base. Across psychedelics there is consistent acute disruption in resting state connectivity within the DMN and increased functional connectivity between canonical resting-state networks. Various models have been proposed to explain the cognitive mechanisms of psychedelics, and in one model DMN modulation is a central axiom. Although the DMN is consistently implicated in psychedelic studies, it is unclear how central the DMN is to the therapeutic potential of classical psychedelic agents. This article aims to provide the field with a comprehensive overview that can propel future research in such a way as to elucidate the neurocognitive mechanisms of psychedelics.

The relationship between cognitive clusters and telomere length in bipolar-schizophrenia spectrum disorders.

BACKGROUND: Schizophrenia and bipolar disorder are complex mental illnesses that are associated with cognitive deficits. There is considerable cognitive heterogeneity that exists within both disorders. Studies that cluster schizophrenia and bipolar patients into subgroups based on their cognitive profile increasingly demonstrate that, relative to healthy controls, there is a severely compromised subgroup and a relatively intact subgroup. There is emerging evidence that telomere shortening, a marker of cellular senescence, may be associated with cognitive impairments. The aim of this study was to explore the relationship between cognitive subgroups in bipolar-schizophrenia spectrum disorders and telomere length against a healthy control sample. METHODS: Participants included a transdiagnostic group diagnosed with bipolar, schizophrenia or schizoaffective disorder (n = 73) and healthy controls (n = 113). Cognitive clusters within the transdiagnostic patient group, were determined using K-means cluster analysis based on current cognitive functioning (MATRICS Consensus Cognitive Battery scores). Telomere length was determined using quantitative PCRs genomic DNA extracted from whole blood. Emergent clusters were then compared to the healthy control group on telomere length. RESULTS: Two clusters emerged within the patient group that were deemed to reflect a relatively intact cognitive group and a cognitively impaired subgroup. Telomere length was significantly shorter in the severely impaired cognitive subgroup compared to the healthy control group. CONCLUSIONS: This study replicates previous findings of transdiagnostic cognitive subgroups and associates shorter telomere length with the severely impaired cognitive subgroup. These findings support emerging literature associating cognitive impairments in psychiatric disorders to accelerated cellular aging as indexed by telomere length.

Characterisation of Deficits and Sex Differences in Verbal and Visual Memory/Learning in Bipolar Disorder.

OBJECTIVE: Cognitive impairment is consistently reported in bipolar disorder (BD), but few studies have characterised which memory component processes are affected. Further, it is unknown whether the component processes underlying memory impairment are moderated by sex. The present study examined diagnosis and sex differences in both verbal and visual memory/learning domains in patients with BD and psychiatrically healthy controls. METHOD: Verbal and visual memory/learning were measured using the Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R). 114 patients with BD (n = 50 males, n = 64 females), were compared to 105 psychiatrically healthy controls (n = 42 males, n = 63 females). RESULTS: Patients with BD had worse performance in verbal and visual immediate and total recall, verbal and visual delayed free recall, and verbal recognition discrimination scores, but there were no group differences in learning slopes and cumulative learning index scores. There were trends for BD females to outperform BD males in visual memory/learning free recall and cumulative learning, but these results did not survive multiple testing correction. These findings did not change in a secondary sensitivity analysis comparing only strictly euthymic BD patients to controls (n = 64). CONCLUSION: The present study found trait-like verbal and visual memory/learning impairment in BD that was attributable to deficient encoding and/or consolidation processes rather than deficits in learning. We did not find marked sex differences in either visual or verbal memory/learning measures, although some trend level effects were apparent and deserve exploration in future studies.