Understanding Cognitive Behavioral Therapy for Psychosis Through the Predictive Coding Framework.

Psychological treatments for persecutory delusions, particularly cognitive behavioral therapy for psychosis, are efficacious; however, mechanistic theories explaining why they work rarely bridge to the level of cognitive neuroscience. Predictive coding, a general brain processing theory rooted in cognitive and computational neuroscience, has increasing experimental support for explaining symptoms of psychosis, including the formation and maintenance of delusions. Here, we describe recent advances in cognitive behavioral therapy for psychosis-based psychotherapy for persecutory delusions, which targets specific psychological processes at the computational level of information processing. We outline how Bayesian learning models employed in predictive coding are superior to simple associative learning models for understanding the impact of cognitive behavioral interventions at the algorithmic level. We review hierarchical predictive coding as an account of belief updating rooted in prediction error signaling. We examine how this process is abnormal in psychotic disorders, garnering noisy sensory data that is made sense of through the development of overly strong delusional priors. We argue that effective cognitive behavioral therapy for psychosis systematically targets the way sensory data are selected, experienced, and interpreted, thus allowing for the strengthening of alternative beliefs. Finally, future directions based on these arguments are discussed.

Delusions are distressing and disabling psychiatric symptoms. Cognitive behavioral therapy for psychosis (CBTp) is the leading psychotherapeutic approach for treating delusions. Predictive coding is a contemporary cognitive neuroscience framework that is increasingly being used to explain mechanisms of delusions. In this article, we attempt to integrate CBTp within the predictive coding framework, outlining how effective CBTp techniques impact aspects of the predictive coding model to contribute to cutting-edge treatment and cognitive neuroscience research on delusions and inform recommendations for treatment advancement.

Modelling the longitudinal dynamics of paranoia in psychosis: A temporal network analysis over 20 years.

BACKGROUND: Paranoia is a key feature of psychosis that can be highly debilitating. Theories of paranoia mostly interface with short-scale or cross-sectional data models, leaving the longitudinal course of paranoia underspecified. METHODS: We develop an empirical characterisation of two aspects of paranoia - persecutory and referential delusions - in individuals with psychosis over 20 years. We examine delusional dynamics by applying a Graphical Vector Autoregression Model to data collected from the Chicago Follow-up Study (n = 135 with a range of psychosis-spectrum diagnoses). We adjusted for age, sex, IQ, and antipsychotic use. RESULTS: We found that referential and persecutory delusions are central themes, supported by other primary delusions, and are strongly autoregressive - the presence of referential and persecutory delusions is predictive of their future occurrence. In a second analysis we demonstrate that social factors influence the severity of referential, but not persecutory, delusions. IMPLICATIONS: We suggest that persecutory delusions represent central, resistant states in the cognitive landscape, whereas referential beliefs are more flexible, offering an important window of opportunity for intervention. Our data models can be collated with prior biological, computational, and social work to contribute toward a more complete theory of paranoia and provide more time-dependent evidence for optimal treatment targets.

Neurocognitive function and delusion severity in schizophrenia spectrum disorders.

The role of basic neurocognitive function in delusions is unclear despite the association to difficulties in reasoning and decision-making. We investigated 812 individuals with schizophrenia spectrum disorders (SSD) using a broad neuropsychological test battery encompassing motor and mental processing speed, working memory, learning and memory, and executive function. Premorbid and current intellectual function was assessed with NART and WASI. Delusion level and other clinical symptoms were measured with the PANSS and GAF. Hierarchical and k-means cluster analysis using standardized scores showed the presence of two separate clusters where the group with the higher delusion level (n = 291) was characterized by more severe neurocognitive deficits (>1.5 standard deviations below the healthy control mean), higher PANSS scores, lower GAF scores, and lower intelligence levels compared to the cluster with mild impairments (n = 521). We conclude that a higher delusion level is related to neurocognitive deficits across domains. Further, the validity of the two separate clusters was indicated by significant differences in clinical symptoms, everyday function, and intellectual ability. Compared to those with mild delusion levels, SSD patients with higher delusion levels seem particularly disadvantaged, with co-occurring general symptoms and lower daily function, underscoring the need for clinical and psychosocial support programs. A limitation of this study is the cross sectional design. Longitudinal studies are needed to determine the causal relationship between delusions and neurocognitive function.

Grief as a Risk Factor for Psychosis: A Systematic Review.

PURPOSE OF REVIEW: The assessment of the risk of triggering psychosis upon exposure to grief is a challenge in clinical practice. Adequate diagnosis and early prevention are essential and may be helpful in the evolution of normal grief. We aimed to identify studies exploring grief as a risk factor for developing psychosis. RECENT FINDINGS: A systematic review of 3 databases (PubMed, EMBASE, and Cochrane Library) was conducted. RESULTS: In the first approach 618 studies were identified. After the selection process, 15 studies were included in the review. The association between grief and the risk of developing psychosis occurred at younger ages (before 18 years of age) in a first-degree relative and as a consequence of suicide or accidental death. We found that risk factors such as comorbidity, mental problems, unemployment, economic difficulties, and close ties with the deceased have a negative impact on health causing greater vulnerability to psychosis with a risk of developing complicated grief, with statistically significant results regarding the associations between early parental death and the probability of developing psychosis in adulthood.

Sense of agency in schizophrenia: A reconciliation of conflicting findings through a theory-driven literature review.

The sense of agency is the experience of being the author of self-generated actions and their outcomes. Both clinical manifestations and experimental evidence suggest that the agency experience and the mechanisms underlying agency attribution may be dysfunctional in schizophrenia. Yet, studies investigating the sense of agency in these patients show seemingly conflicting results: some indicated under-attribution of self-agency (coherently with certain positive symptoms), while others suggested over-attribution of self-agency. In this review, we assess whether recent theoretical frameworks can reconcile these divergent results. We examine whether the identification of agency abnormalities in schizophrenia might depend on the measure of self-agency considered (depending on the specific task requirements) and the available agency-related cues. We conclude that all these aspects are relevant to predict and characterize the type of agency misattribution that schizophrenia patients might show. We argue that one particular model, based on the predictive coding theory, can reconcile the interpretation of the multifarious phenomenology of agency manifestations in schizophrenia, paving the way for testing agency disorders in novel ways.

Altered Perception of Environmental Volatility During Social Learning in Emerging Psychosis.

Paranoid delusions or unfounded beliefs that others intend to deliberately cause harm are a frequent and burdensome symptom in early psychosis, but their emergence and consolidation still remains opaque. Recent theories suggest that overly precise prediction errors lead to an unstable model of the world providing a breeding ground for delusions. Here, we employ a Bayesian approach to test for such an unstable model of the world and investigate the computational mechanisms underlying emerging paranoia. We modelled behaviour of 18 first-episode psychosis patients (FEP), 19 individuals at clinical high risk for psychosis (CHR-P), and 19 healthy controls (HC) during an advice-taking task designed to probe learning about others' changing intentions. We formulated competing hypotheses comparing the standard Hierarchical Gaussian Filter (HGF), a Bayesian belief updating scheme, with a mean-reverting HGF to model an altered perception of volatility. There was a significant group-by-volatility interaction on advice-taking suggesting that CHR-P and FEP displayed reduced adaptability to environmental volatility. Model comparison favored the standard HGF in HC, but the mean-reverting HGF in CHR-P and FEP in line with perceiving increased volatility, although model attributions in CHR-P were heterogeneous. We observed correlations between perceiving increased volatility and positive symptoms generally as well as with frequency of paranoid delusions specifically. Our results suggest that FEP are characterised by a different computational mechanism - perceiving the environment as increasingly volatile - in line with Bayesian accounts of psychosis. This approach may prove useful to investigate heterogeneity in CHR-P and identify vulnerability for transition to psychosis.

Effect of applying nursing-based cognitive defusion techniques on mindful awareness, cognitive fusion, and believability of delusions among clients with schizophrenia: a randomized control trial.

Background: Applying cognitive defusion techniques to enduring psychotic symptoms, such as delusions, presents both a challenge and a promising opportunity for psychiatric nurses to manage delusions among schizophrenia clients. Objective: This study aimed to examine the impact of cognitive defusion techniques on psychological flexibility, mindful awareness, cognitive fusion, and the believability of delusions in schizophrenia clients. Methodology: This study used a single-blind, parallel-arm Randomized Controlled Trial design. Over five weeks, 70 clients with schizophrenia were randomized to either the cognitive defusion intervention group (n = 35) or the control group (n = 35). Findings: The participants showed significant reductions in the believability of delusions, cognitive fusion, and psychological inflexibility immediately after the intervention and at follow-up. Notable enhancements were observed in cognitive defusion and mindfulness awareness abilities. Conclusion: Cognitive defusion techniques positively affect schizophrenia clients who struggle with persistent delusional beliefs. This underscores the importance of further investigating this approach to decrease the intensity of delusions as part of a comprehensive therapeutic intervention. Psychiatric nurses must receive training in "cognitive defusion skills" to aid schizophrenia clients in becoming more aware of their emotions and modifying their coping strategies for delusional beliefs. On August 3, 2023, the research was retrospectively registered under the reference number NCT05759091 as a randomized clinical trial. Clinical trial registration: https://classic.clinicaltrials.gov/ct2/show/NCT05759091, identifier NCT05759091.

Revisiting Cognitive Deficits in Outpatients with Psychotic Disorders: A Transdiagnostic Comparison of Cognitive Performance While Accounting for Putative Confounding Factors.

Recent research suggests that cognitive deficits in individuals with psychotic disorders could be overestimated because poor cognitive test performance is partly attributable to non-cognitive factors. To further test this, we included non-hospitalized individuals with psychotic disorders (PSY, n = 38), individuals with attenuated psychotic symptoms (n = 40), individuals with obsessive-compulsive disorders (n = 39), and healthy controls (n = 38). Relevant cognitive domains were assessed using the MATRICS Consensus Cognitive Battery. Putative confounding non-cognitive factors-heart rate, self-reported stress, negative affect, performance-related beliefs, and actigraphy-derived sleep-were assessed before cognitive testing. A multivariate analysis of covariance was calculated to examine group differences in cognitive performance while controlling for non-cognitive factors. PSY showed decreased test performance in graphomotor speed, attention, and verbal tasks compared to the other groups, whereas non-verbal/visual-spatial tasks were unimpaired. After accounting for non-cognitive factors, group differences diminished in verbal learning, whereas differences in the other domains remained significant. Against our hypotheses, the present findings indicate that some cognitive deficits in PSY cannot be attributed to momentary confounding factors.

Delusions and Delinquencies: A Comparison of Violent and Non-Violent Offenders With Schizophrenia Spectrum Disorders.

The relationship between schizophrenia spectrum disorders (SSD) and violent offending has long been the subject of research. The present study attempts to identify the content of delusions, an understudied factor in this regard, that differentiates between violent and non-violent offenses. Limitations, clinical relevance, and future directions are discussed. Employing a retrospective study design, machine learning algorithms and a comprehensive set of variables were applied to a sample of 366 offenders with a schizophrenia spectrum disorder in a Swiss forensic psychiatry department. Taking into account the different contents and affects associated with delusions, eight variables were identified as having an impact on discriminating between violent and non-violent offenses with an AUC of 0.68, a sensitivity of 30.8%, and a specificity of 91.9%, suggesting that the variables found are useful for discriminating between violent and non-violent offenses. Delusions of grandiosity, delusional police and/or army pursuit, delusional perceived physical and/or mental injury, and delusions of control or passivity were more predictive of non-violent offenses, while delusions with aggressive content or delusions associated with the emotions of anger, distress, or agitation were more frequently associated with violent offenses. Our findings extend and confirm current research on the content of delusions in patients with SSD. In particular, we found that the symptoms of threat/control override (TCO) do not directly lead to violent behavior but are mediated by other variables such as anger. Notably, delusions traditionally seen as symptoms of TCO, appear to have a protective value against violent behavior. These findings will hopefully help to reduce the stigma commonly and erroneously associated with mental illness, while supporting the development of effective therapeutic approaches.

Sociodemographic and clinical correlates of hallucinations in patients entering an early intervention program for first episode psychosis.

Hallucinations are a core feature of psychosis, and their severity during the acute phase of illness is associated with a range of poor outcomes. Various clinical and sociodemographic factors may predict hallucinations and other positive psychotic symptoms in first episode psychosis (FEP). Despite this, the precise factors associated with hallucinations at first presentation to an early intervention service have not been extensively researched. Through detailed interviews and chart reviews, we investigated sociodemographic and clinical predictors in 636 minimally-medicated patients who entered PEPP-Montréal, an early intervention service for FEP, between 2003 and 2018. Hallucinations were measured using the Scale for the Assessment of Positive Symptoms (SAPS), while negative symptoms were assessed using the Scale for the Assessment of Negative symptoms (SANS). Depressive symptoms were evaluated through the Calgary Depression Scale for Schizophrenia (CDSS), and anxiety symptoms via the Hamilton Rating Scale for Anxiety (HAS). A majority (n = 381, 59.9 %) of the sample presented with clinically significant hallucinations (SAPS global hallucinations score ≥ 3) at program entry. These patients had an earlier age at onset, fewer years of education, and a higher severity of delusions, depression and negative symptoms than those without clinical-level hallucinations. These results suggest that individuals with clinically significant hallucinations at admission tend to be younger and have a greater overall symptom burden. This makes it especially important to monitor hallucinations alongside delusions, depression and negative symptoms in order to identify who might benefit from targeted interventions. The implications of these findings for early intervention and person-centered care are discussed.

Psychotic-like experiences and problem drinking among adults in Japan.

BACKGROUND: Psychotic-like experiences (PLEs) are common in the general population and have been linked to alcohol misuse and abuse. However, much of this research has been undertaken in Western countries. To address this deficit, the current study examined the association between PLEs and problem drinking in the Japanese general population. METHODS: Data were used from 3717 adults (age 18-89) collected in an online survey in 2023. Information was obtained on PLEs with the PRIME Screen-Revised (PS-R), while problem drinking was assessed with the CAGE questionnaire (where a score of ≥ 2 was used to categorize cases). Logistic regression was used to examine the associations. RESULTS: Problem drinking was prevalent in the study sample (12.5%). In an analysis that was adjusted for sociodemographic factors, self-rated health, smoking status and depressive symptoms, PLEs were associated with significantly higher odds for problem drinking in the total sample (OR: 1.70, 95%CI: 1.13-2.55). In a sex-stratified analysis PLEs were not linked to problem drinking in men (OR: 1.16, 95%CI 0.68-2.00), whereas women with PLEs had over 2.8 times higher odds for problem drinking (OR: 2.83, 95%CI: 1.54-5.21). CONCLUSION: PLEs are associated with problem drinking in the Japanese general population and this association is especially pronounced in women. As problem drinking has been linked to a number of detrimental outcomes, future research should examine the potential effects of problem drinking in individuals with PLEs.

Pseudociesis. Reporte de caso / Psedocyesis. Case report

Introducción: Según el DSM-V, la pseudociesis se incluye en la categoría "otros síntomas somáticos específicos y trastornos relacionados" y se define como la falsa creencia de estar embarazada que se asocia con signos objetivos y síntomas de embarazo. La confirmación de la pseudociesis se consigue con un resultado negativo de la gonadotropina coriónica humana beta en la sangre y/o la orina asociado a un hallazgo ecográfico negativo. Materiales y métodos: se presenta el caso de mujer con síntomas y signos de embarazo que corresponden a pseudociesis, la paciente siguió creyendo que estaba embarazada debido a sus síntomas, a pesar de que las pruebas de embarazo dieron negativo. Conclusión: La pseudociesis es una enfermedad poco frecuente que a menudo se asocia a otras comorbilidades psiquiátricas y diagnósticos diferenciales poco claros. Es necesario la realización de más estudios, incluyendo series de casos y revisiones sistemáticas para comprender mejor esta infrecuente condición y sus otras variantes.

Introduction: According to the DSM-V, pseudocyesis is included in the category "other specific somatic symptoms and related disorders" and is defined as a false belief of being pregnant that is associated with objective signs and symptoms of pregnancy. Confirmation of pseudocyesis is achieved with a negative blood and/or urine beta-human chorionic gonadotropin result and a negative ultrasound finding. Materials and methods: We present a case of a woman with symptoms and signs of pregnancy corresponding to pseudocyesis, the patient continued to believe she was pregnant because of her symptoms, despite negative pregnancy tests. Conclusion: Pseudocyesis is a rare condition that is often associated with other psychiatric comorbidities and unclear differential diagnoses. Further studies, including case series and systematic reviews, are needed to better understand this rare condition and its other variants.

Psychiatric manifestations in moyamoya disease: more than a puff of smoke? a systematic review and a case-reports meta-analysis.

Introduction: Moyamoya disease (MMD) is a life-threatening condition characterized by stenosis of intracranial arteries. Despite the frequency and the impact of psychiatric symptoms on the long-term prognosis and quality of life of MMD patients, no systematic review on this topic exists. Methods: This systematic review and meta-analysis included 41 studies (29 being case reports), from PubMed, Scopus, Embase until 27/3/2023, on MMD patients exhibiting psychiatric symptoms. Results: Despite a fair average quality of the articles, quantitative synthesis through logistic regression was possible only for case reports, due to heterogeneity between the other studies. Psychosis, the most frequent psychiatric symptom reported in case reports, was more frequent in MMD patients with left hemisphere involvement. Neurological symptoms occurrence increased the odds of MMD diagnosis preceding psychiatric symptoms. Psychiatric symptoms are highly prevalent in MMD patients and are relatively often the only presenting symptoms. Discussion: We discuss the diagnostic, therapeutic, and prognostic implications of recognizing and characterizing specific psychiatric symptoms in MMD, outlining preliminary guidelines for targeted pharmacological and psychotherapeutic interventions. Lastly, we outline future research and clinical perspectives, striving to enhance the oft-overlooked psychiatric care for MMD patients and to ameliorate their long-term outcome. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023406303.

Exploring Psychosis in Neurodegenerative Dementia: Connecting Symptoms to Neurobiology.

The following commentary discusses a review by Cressot et al. entitled: 'Psychosis in Neurodegenerative Dementias: A Systematic Comparative Review'. The authors describe the epidemiology and phenomenology of psychosis across neurodegenerative dementias. Dementia with Lewy bodies had the highest reported prevalence of psychosis at 74% followed by Alzheimer's disease, 54% and frontotemporal degeneration, 42%. Detailed characterization of psychosis shows differences in the types of hallucinations and delusions by dementia type. These findings suggest that different types of dementia related pathology are associated with high rates of psychosis with more specific symptom profiles than previously appreciated. Understanding the differences and variety of psychotic experiences across dementia types may have diagnostic and therapeutic implications for treating hallucinations and delusions in populations suffering from neurodegenerative diseases.

From hallucinations to delusions: A narrative review of psychotic-like experiences and their implications.

Psychotic-like experiences (PLEs) refer to sub-threshold hallucinations and delusions observed in both clinical samples and the general population. Psychotic-like experiences have far-reaching implications for an individual's coping strategies and daily functioning. They are associated with both psychotic and non-psychotic disorders. This article presents a comprehensive review of the current literature on PLEs, incorporating a detailed exploration of the definition, prevalence, risk factors, functional impairments, and comorbid psychiatric disorders. Medline/PubMed and Embase were searched to establish and identify the literature. A total of 108 studies met our inclusion criteria. The genetic and biochemical backgrounds of PLEs are discussed, focusing on gene polymorphisms, changes in brain gyrification and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Psychological factors, such as trauma exposure, emotion regulation difficulties, cognitive biases, and attachment issues, were thoroughly examined, especially in terms of their impact on the emergence of PLEs. Here, we show how important the clinical aspects of developmental PLEs are, underlining the significance of an increased risk of self-harm and suicidal behaviors in those individuals and the comorbidity of psychiatric disorders in enabling clinicians to discern specific areas to observe. Although there is limited evidence on effective protocols for PLE management, various treatment approaches are explained. Despite increased research on PLEs in recent years, further investigation is needed to fully understand the nature of PLEs and to optimize therapeutic strategies. This article consolidates the current knowledge by synthesizing information on PLEs, including risk factors, comorbidities, treatments, and their impact on individual's lives.

A Unique Delusion with Depression in Early Stage of Neurocognitive Disorder Due to Vascular Disease: Considerations for Clinicians.

As global aging becomes more prominent, neurocognitive disorders (NCD) incidence has increased. Patients with NCD usually have an impairment in one or more cognitive domains, such as attention, planning, inhibition, learning, memory, language, visual perception, and spatial or social skills. Studies indicate that 50-80% of these adults will develop neuropsychiatric symptoms (NPS), such as apathy, depression, anxiety, disinhibition, delusions, hallucinations, and aberrant motor behavior. The progression of NCD and subsequent NPS requires tremendous care from trained medical professionals and family members. The behavioral symptoms are often more distressing than cognitive changes, causing caregiver distress/depression, more emergency room visits and hospitalizations, and even earlier institutionalization. This signifies the need for early identification of individuals at higher risk of NPS, understanding the trajectory of their NCD, and exploring treatment modalities. In this case report and review, we present an 82-year-old male admitted to our facility for new-onset symptoms of depression, anxiety, and persecutory delusions. He has no significant past psychiatric history, and his medical history is significant for extensive ischemic vascular disease requiring multiple surgeries and two episodes of cerebrovascular accident (CVA). On further evaluation, the patient was diagnosed with major NCD, vascular subtype. We discuss differential diagnoses and development of NPS from NCD in order to explain the significance of more thorough evaluation by clinicians for early detection and understanding of NCD prognosis.

Different learning aberrations relate to delusion-like beliefs with different contents.

The prediction error account of delusions has had success. However, its explanation of delusions with different contents has been lacking. Persecutory delusions and paranoia are the common unfounded beliefs that others have harmful intentions towards us. Other delusions include believing that one's thoughts or actions are under external control, or that events in the world have specific personal meaning. We compare learning on two different cognitive tasks, probabilistic reversal learning (PRL) and Kamin blocking, that have relationships to paranoid and non-paranoid delusion-like beliefs, respectively. We find that Clinical High-Risk status alone does not result in different behavioral results on the PRL task but that an individual's level of paranoia is associated with excessive switching behavior. During the Kamin blocking task, paranoid individuals learned inappropriately about the blocked cue. However, they also had decreased learning about the control cue, suggesting more general learning impairments. Non-paranoid delusion-like belief conviction (but not paranoia) was associated with aberrant learning about the blocked cue but intact learning about the control cue, suggesting specific impairments in learning related to cue combination. We fit task-specific computational models separately to behavioral data to explore how latent parameters vary within individuals between tasks, and how they can explain symptom-specific effects. We find that paranoia is associated with low learning rates on the PRL task as well as the blocking task. Non-paranoid delusion-like belief conviction was instead related to parameters controlling the degree and direction of similarity between cue updating during simultaneous cue presentation. These results suggest that paranoia and other delusion-like beliefs involve dissociable deficits in learning and belief updating, which - given the transdiagnostic status of paranoia - may have differential utility in predicting psychosis.

Corrigendum: Thinking preferences and conspiracy belief: intuitive thinking and the jumping to conclusions-bias as a basis for the belief in conspiracy theories.

[This corrects the article DOI: 10.3389/fpsyt.2020.568942.].

Impact of Delusions and Hallucinations on Clinical Insight Dimensions in Schizophrenia Spectrum Disorders.

INTRODUCTION: Insight in psychosis has been conceptualized as a continuous, dynamic, and multidimensional phenomenon. This study aims to determine the impact of delusions and hallucinations in different dimensions of clinical insight in schizophrenia spectrum disorders. METHODS: Cross-sectional multicenter study including 516 patients (336 men) diagnosed with schizophrenia spectrum disorders. Based on dichotomized scores of Positive and Negative Syndrome Scale (PANSS) items P1 (delusions) and P3 (hallucinations), patients were assigned to four groups according to current clear presence of delusions (scores 4 or above 4 in PANSS item P1) and/or hallucinations (scores 4 or above 4 in PANNS item P3). Insight was assessed using the three main dimensions of the Scale of Unawareness of Mental Disorder (SUMD). RESULTS: Around 40% of patients showed unawareness of illness; 30% unawareness of the need for treatment; and 45% unawareness of the social consequences of the disorder. Patients with current clear presence of delusions had higher overall lack of awareness, regardless of current clear presence of hallucinations. Similarly, the clear presence of delusions showed a greater predictive value on insight than the presence of hallucinations, although the implication of both in the prediction was modest. CONCLUSIONS: Our results confirm that lack of insight is highly prevalent in schizophrenia spectrum disorders, particularly when patients experience delusions. This study adds insight-related data to the growing symptom-based research, where specific types of psychotic experiences such as hallucinations and delusions could form different psychopathological patterns, linking the phenomenology of delusions to a lack of clinical insight.