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Delusions are rigid beliefs held with high certainty despite contradictory evidence. Notwithstanding decades of research, we still have a limited understanding of the computational and neurobiological alterations giving rise to delusions. In this review, we highlight a selection of recent work in computational psychiatry aimed at developing quantitative models of inference and its alterations, with the goal of providing an explanatory account for the form of delusional beliefs in psychosis. First, we assess and evaluate the experimental paradigms most often used to study inferential alterations in delusions. Based on our review of the literature and theoretical considerations, we contend that classic draws-to-decision paradigms are not well-suited to isolate inferential processes, further arguing that the commonly cited ‘jumping-to-conclusion’ bias may reflect neither delusion-specific nor inferential alterations. Second, we discuss several enhancements to standard paradigms that show promise in more effectively isolating inferential processes and delusion-related alterations therein. We further draw on our recent work to build an argument for a specific failure mode for delusions consisting of prior overweighting in high-level causal inferences about partially observable hidden states. Finally, we assess plausible neurobiological implementations for this candidate failure mode of delusional beliefs and outline promising future directions in this area.

Background Study aims were to analyze psychopathological details of prodromes leading to first-lifetime psychotic episodes and apply them to improve prediction of final diagnoses. Methods Comprehensive records of subjects with final diagnoses of bipolar I (BD-I; n = 216), schizoaffective (SzAffD; n = 71), or psychotic major-depressive (MDD; n = 42) disorders in the Harvard-McLean First-Psychotic Episode Project were analyzed to identify psychopathological details of prodromes leading to first-lifetime episodes with psychotic features and their ability to predict final diagnoses tested with multivariable logistic regression modeling. Results While held blind to final diagnoses, we identified 84 distinct psychopathological characteristics of prodromes to first-psychotic episodes, including perceptual disturbances, affective symptoms, sleep disturbances, onset rate, and duration. Prevalence of 19 factors appeared to differ among final diagnoses, and were tested with multivariable regression modeling. Significantly and independently more associated with final diagnoses of MDD than BD-I were 7 features: suicidal ideation, somatic delusions, anorexia, lack of insomnia, older presenting age, depressive symptoms, and lack of impulsivity; 9 others were associated more with later SzAffD than MDD or BD-I: lack of insomnia, homicidal behavior, lack of excitement, visual hallucinations, command hallucinations, longer prodrome, male sex, responding to internal stimuli, and younger age at presentation. Limitations Historical-retrospective and prospective assessments may have misidentified some prodromal features, and subjects with final psychotic-MDD diagnosis were relatively few. Conclusions Psychopathological features identified during prodromes leading to first-episodes with psychotic features predicted and distinguished among final diagnoses of MDD, BD-I, and SzAffD. The findings add to growing impressions that early psychopathology has value in predicting final diagnoses of major affective and schizoaffective disorders.

Rates of antimicrobial resistance are increasing globally while the pipeline of new antibiotics is drying up, putting patients with disease caused by drug-resistant bacteria at increased risk of complications and death. The growing costs for diagnosis and management of drug resistance threaten tuberculosis control where the disease is endemic and resources limited. Bacteriophages are viruses that attack bacteria. Phage preparations served as anti-infective agents long before antibiotics were discovered. Though small in size, phages are the most abundant and diverse biological entity on earth. Phages have co-evolved with their hosts and possess all the tools needed to infect and kill bacteria, independent of drug resistance. Modern biotechnology has improved our understanding of the biology of phages and their possible uses. Phage preparations are available to treat meat, fruit, vegetables, and dairy products against parasites or to prevent contamination with human pathogens, such as Listeria monocytogenes, Escherichia coli, or Staphylococcus aureus. Such phage-treated products are considered fit for human consumption. A number of recent case reports describe in great detail the successful treatment of highly drug-resistant infections with individualized phage preparations. Formal clinical trials with standardized products are slowly emerging. With its highly conserved genome and relative paucity of natural phage defence mechanisms Mycobacterium tuberculosis appears to be a suitable target for phage treatment. A phage cocktail with diverse and strictly lytic phages that kill all lineages of M. tuberculosis, and can be propagated on Mycobacterium smegmatis, has been assembled and is available for the evaluation of optimal dosage and suitable routes of administration for tuberculosis in humans. Phage treatment can be expected to be safe and active on extracellular organisms, but phage penetration to intracellular and granulomatous environments as well as synergistic effects with antibiotics are important questions to address during further evaluation.

Aim This report aims to illustrate the possibility of an acute onset of psychosis after COVID‐19 infection in a patient without previous history of psychiatric disorders and to highlight the need for early screening and intervention in such cases. Methods Clinical presentation of a case, followed by clinical discussion and literature review of the effect of the new coronavirus SARS‐CoV‐2 and its impact on mental health in terms of neuropsychiatric conditions. Results We present a case of acute and transient psychotic disorder following complete recovery of COVID‐19 bilateral pneumonia. The patient has no prior psychiatric history and presents with acute onset, disorganized behaviour, Cotard's delusion and a potentially high risk of psychotic homicide and suicide. Conclusion Early intervention and treatment with antipsychotic medication are of crucial importance for the effective treatment and complete recovery of these patients.

We present associations between neuropsychiatric symptoms (NPS) and brain morphology in a large sample of patients with mild cognitive impairment (MCI) and Alzheimer's disease with dementia (AD dementia). Several studies assessed NPS factor structure in MCI and AD dementia, but we know of no study that tested for associations between NPS factors and brain morphology. The use of factor scores increases parsimony and power. For transparency, we performed an additional analysis with selected Neuropsychiatric Inventory - Questionnaire (NPI-Q) items. Including regional cortical thickness, cortical and subcortical volumes, we examined associations between NPS and brain morphology across the whole brain in an unbiased fashion. We reported both statistical significance and effect sizes, using linear models adjusted for multiple comparisons by false discovery rate (FDR). Moreover, we included an interaction term for diagnosis and could thereby compare associations of NPS and brain morphology between MCI and AD dementia. We found an association between the factor elation and thicker right anterior cingulate cortex across MCI and AD dementia. Associations between the factors depression to thickness of the banks of the left superior temporal sulcus and psychosis to the left post-central volume depended on diagnosis: in MCI these associations were positive, in AD dementia negative. Our findings indicate that NPS in MCI and AD dementia are not exclusively associated with atrophy and support previous findings of associations between NPS and mainly frontotemporal brain structures.Objectives: Neuropsychiatric symptoms (NPS) are common in mild cognitive impairment (MCI) and Alzheimer's disease with dementia (AD dementia), but their brain structural correlates are unknown. We tested for associations between NPS and MRI-based cortical and subcortical morphometry in patients with MCI and AD dementia. Design: Cross-sectional. Settings: Conducted in Norway. Participants: Patients with MCI (n = 102) and AD dementia (n = 133) from the Memory Clinic and the Geriatric Psychiatry Unit at Oslo University Hospital. Measurements: Neuropsychiatric Inventory - Questionnaire (NPI-Q) severity indices were reduced using principal component analysis (PCA) and tested for associations with 170 MRI features using linear models and false discovery rate (FDR) adjustment. We also tested for differences between groups. For transparency, we added analyses with selected NPI-Q items. Results: PCA revealed four factors: elation, psychosis, depression, and motor behavior. FDR adjustment revealed a significant positive association (B = 0.20, p(FDR) < 0.005) between elation and thickness of the right caudal anterior cingulate cortex (ACC) across groups, and significant interactions between diagnosis and psychosis (B = -0.48, p(FDR) < 0.0010) on the left post-central volume and between diagnosis and depression (B = -0.40, p(FDR) < 0.005) on the thickness of the banks of the left superior temporal sulcus. Associations of apathy, anxiety, and nighttime behavior to the left temporal lobe were replicated. Conclusions: The positive association between elation and ACC thickness suggests that mechanisms other than atrophy underly elation. Interactions between diagnosis and NPS on MRI features suggest different mechanisms of NPS in our MCI and AD dementia samples. The results contribute to a better understanding of NPS brain mechanisms in MCI and AD dementia.

BackgroundUnderstanding the interplay between trauma-related psychological mechanisms and psychotic symptoms may improve the effectiveness of interventions for post-traumatic stress reactions in psychosis. Network theory assumes that mental health problems persist not because of a common latent variable, but from dynamic feedback loops between symptoms, thereby addressing the heterogeneous and overlapping nature of traumagenic and psychotic diagnoses. This is a proof-of-concept study examining interactions between post-traumatic stress symptoms, which were hypothesized to reflect trauma-related psychological mechanisms, and auditory hallucinations and delusions.MethodBaseline data from two randomised controlled trials (N = 216) of trauma-focused therapy in people with post-traumatic stress symptoms (87.5% met diagnostic criteria for PTSD) and psychotic disorder were analysed. Reexperiencing, hyperarousal, avoidance, trauma-related beliefs, auditory hallucinations and delusional beliefs were used to estimate a Gaussian graphical model along with expected node influence and predictability (proportion of explained variance).ResultsTrauma-related beliefs had the largest direct influence on the network and, together with hypervigilance, were implicated in the shortest paths from flashbacks to delusions and auditory hallucinations.ConclusionsThese findings are in contrast to previous research suggesting a central role for re-experiencing, emotional numbing and interpersonal avoidance in psychosis. Trauma-related beliefs were the psychological mechanism most associated with psychotic symptoms, although not all relevant mechanisms were measured. This work demonstrates that investigating multiple putative mediators may clarify which processes are most relevant to trauma-related psychosis. Further research should use network modelling to investigate how the spectrum of traumatic stress reactions play a role in psychotic symptoms.

Corticobasal syndrome (CBS) is one of the Parkinson-plus disorders. While initially defined as a movement disorder rather than cognition, it is now known that CBS is related to various psychiatric symptoms. We describe a patient clinically diagnosed with CBS whose initial presentation was psychiatric and rather atypical. His clinical picture included psychotic depression and delusional jealousy. Misdiagnosing these syndromes may delay the initiation of the treatment and worsen the patients' condition, as well as increase the burden of the caretakers. Finally, COVID-19-related changes in the organization of health services complicated the diagnosis and follow-up processes of this patient.

This study describes the person-centered experience and impact of symptoms and the treatment needs of dementia-related psychosis (DRP) from a patient and care partner perspective.Qualitative interviews and a quantitative survey were used to collect patient experience data from persons with DRP or their care partners.Sixteen participants (1 person with DRP, 15 care partners) completed the qualitative interview; 212 participants (26 persons with DRP, 186 care partners) completed the quantitative survey. The most commonly reported symptoms were visual hallucinations, auditory hallucinations, persecutory delusions, and distortion of senses. The most common impacts were difficulty differentiating what is real from what is not real, increased anxiety, and effects on personal relationships. Current treatments were less than moderately helpful, and the ability to distinguish what is real from what is not real and overall symptom improvement were described as the most important benefits of an ideal treatment.Patient experience data provide insights into urgent therapeutic needs of patients by describing the nature, frequency, and severity of symptoms and the impacts they have on individuals' lives.Patient experience data demonstrate an unmet need for treatments to reduce the symptoms and impacts of DRP.

The EUGEI project was supported by the European Community's Seventh Framework Program under grant agreement No. HEALTH-F2-2009-241909 (Project EU-GEI). Dr O'Donovan is supported by MRC programme grant (G08005009) and an MRC Centre grant (MR/L010305/1), Henquet, C., Van Os, J., Pries, L.K., Rauschenberg, C., Delespaul, P., Kenis, G., Luykx, J.J., Lin, B.D., Richards, A.L., Akdede, B., Binbay, T., Altlnyazar, V., Yallnçetin, B., Gümüş-Akay, G., Cihan, B., Soygür, H., Ulaş, H., Cankurtaran, E.S., Kaymak, S.U., Mihaljevic, M.M., Petrovic, S.S., Mirjanic, T., Bernardo, M., Mezquida, G., Amoretti, S., Bobes, J., Saiz, P.A., Garciá-Portilla, M.P., Sanjuan, J., Aguilar, E.J., Santos, J.L., Jiménez-López, E., Arrojo, M., Carracedo, A., López, G., González-Penãs, J., Parellada, M., Maric, N.P., Atbaşoelu, C., Ucok, A., Alptekin, K., Saka, M.C., Arango, C., O'Donovan, M., Rutten, B.P.F., Gülöksüz, S.

Despite the ubiquity of delusional information processing in psychopathology and everyday life, formal characterizations of such inferences are lacking. In this article, we propose a generative framework that entails a computational mechanism which, when implemented in a virtual agent and given new information, generates belief updates (i.e., inferences about the hidden causes of the information) that resemble those seen in individuals with delusions. We introduce a particular form of Dirichlet process mixture model with a sampling-based Bayesian inference algorithm. This procedure, depending on the setting of a single parameter, preferentially generates highly precise (i.e. over-fitting) explanations, which are compartmentalized and thus can co-exist despite being inconsistent with each other. Especially in ambiguous situations, this can provide the seed for delusional ideation. Further, we show by simulation how the excessive generation of such over-precise explanations leads to new information being integrated in a way that does not lead to a revision of established beliefs. In all configurations, whether delusional or not, the inference generated by our algorithm corresponds to Bayesian inference. Furthermore, the algorithm is fully compatible with hierarchical predictive coding. By virtue of these properties, the proposed model provides a basis for the empirical study and a step toward the characterization of the aberrant inferential processes underlying delusions., Schizophrenia Research, 245, ISSN:0920-9964, ISSN:1573-2509

Background: Obsessive-compulsive disorder (OCD) is associated with heterogeneous and diverse symptoms. A diagnosis is challenging when patients experience psychotic symptoms. This study aimed to evaluate the pattern of psychotic symptoms in patients with OCD. Methods: Using semi-structured clinical interviews, 185 patients meeting the DSM-IV diagnostic criteria for OCD were selected. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Scale for the Assessment of Positive/Negative Symptoms (SAPS/SANS) were used to measure the OCD severity and insight levels and the pattern of psychotic symptoms, respectively. Characteristics of patients with and without psychotic experiences were compared. Results: A total of 38 patients (20.5%) displayed psychotic symptoms. Delusions were observed in 63.2% of these patients, while in 13.2% of them, delusions were accompanied with negative symptoms. Men, those aged between 18 and 34 years, less educated, and singles displayed significantly higher rates of psychotic symptoms. The mean Y-BOCS score (26.42±5.07) was significantly higher in patients with psychotic symptoms than in those without (24.97±6.38). Conclusion: The results showed that in OCD patients, psychotic symptoms are more common in young (

Background: Behavioral variant frontotemporal dementia (bvFTD) is generally considered a young-onset dementia, although age at onset is highly variable. While several studies indicate clinical differences regarding age at onset, no biomarker validated cohort studies with updated clinical criteria have been performed. Objective: We aimed to examine behavior, cognition, and mortality over the full age spectrum in a cohort of bvFTD patients with neuroimaging, genetic, or histopathological confirmation and exclusion of positive Alzheimer’s disease biomarkers or severe cerebrovascular damage. Methods: In total, 315 patients with a clinical diagnosis of probable or definite bvFTD were included from the Amsterdam Dementia Cohort and grouped into quartiles by age-at-diagnosis. Neuropsychiatric symptoms and cognitive functioning were assessed with the neuropsychiatric inventory, the geriatric depression scale and a neuropsychological test battery. Data on mortality was obtained from the Dutch municipal register. Associations between age-at-diagnosis and clinical features and mortality risk were examined. Results: Age-at-diagnosis ranged from 26 to 85 years and established quartiles with mean ages of 52±6, 61±2, 66±2, and 74±3 years. In the total sample, 44.4%exceeded an age of 65 years at time of diagnosis. Earlier age-at-diagnosis was associated with more severe behavioral symptoms, while later age-at-diagnosis was associated with more severe memory impairment. Unexpectedly, mortality risk was not associated with age-at-diagnosis. Conclusion: In bvFTD, symptom profile is associated with age-at-diagnosis. This should be taken into account with regard to diagnostics, patient management, and trial design. Additionally, based on our sample, the prevalence of late-onset bvFTD is higher than generally thought.

Othello syndrome (OS) is a type of delusional jealousy, characterized by the false absolute certainty of the infidelity of a partner. This syndrome is not uncommon in Parkinson's Disease (PD), appearing as side effect of Dopaminergic Agonists (DA) therapy. We analyze the observations of five patients with OS, diagnosed in a series of 250 consecutive PD patients during two years. All patients are men, with a particularly young age at onset of PD. The mean duration of DA therapy at OS onset was 3 years. One patient had hypersexuality and another had punding. Significant cognitive impairment was present in two patients. All patients were treated with DA: two with Pramipexol and three with Piribedil. At the time of the management of the OS, three patients had already divorced their spouse. It is imperative for clinicians to know this underestimated syndrome in order to identify it early and approach it adequately to avoid irreversible negative prejudice.

Metabolic, toxic or structural brain changes may present as psychotic symptoms. Organic delusional disorders are characterized by the presence of delusional ideas with evidence of brain dysfunction. Iatrogenesis may be a cause of this dysfunction. We present a case of neuropsychiatric symptoms, including delusional disorder, secondary to the use of herbal products. The patient's perception regarding the safety of natural products might result in an omission to report their use during clinical history taking, and thus its use should be actively questioned.Sintomas psicóticos podem constituir a forma de apresentação de alterações estruturais, metabólicas ou tóxicas. As perturbações delirantes orgânicas são caraterizadas pela presença de ideias delirantes com evidência de disfunção cerebral. A iatrogenia pode ser uma causa desta disfunção. Apresentamos um caso de sintomas neuropsiquiátricos, incluindo perturbação delirante, secundária ao uso de produtos de ervanária. A noção de inocuidade associada a estes produtos origina que o consumo dos mesmos não seja referido espontaneamente pelo doente na recolha da história clínica, pelo que a sua utilização deve ser ativamente questionada.

This case report describes a unique presentation of Cotard syndrome in an 18-year-old female patient experiencing first-episode psychosis. Cotard syndrome was first described in 1880 by Jules Cotard as a novel subtype of anxious depression and is presently understood as a rare cluster of mood and psychotic symptoms centered on nihilistic delusions including the absence of organs and a perception of being dead. Although rare, Cotard syndrome has been described in a variety of neurological and psychiatric illnesses, but it is most commonly seen in middle-aged adults with a history of chronic mood disorders. It is rarely reported in childhood or adolescence, and it has not previously been described in first-episode psychosis. This report describes a unique presentation of full Cotard syndrome in an adolescent patient experiencing first-episode psychosis without reported mood symptoms. The patient displayed limited improvement over the first week of treatment with quetiapine but improved rapidly during the second week of hospitalization after a medication change to risperidone. The patient's rapid response to risperidone is unique, as most existing evidence suggests that electroconvulsive therapy is the most effective treatment for Cotard syndrome. This response indicates an opportunity for the implementation of a second-generation antipsychotic medication in patients with Cotard syndrome in areas where electroconvulsive therapy is not available.

Background Emerging data suggest cannabis use is a component cause of psychotic disorders; however, the sequence of processes accounting for this association is poorly understood. Some clues have come from studies in laboratory settings showing that acute cannabis intoxication is associated with subclinical hallucinations and delusional thinking, i.e., “psychotic experiences”. Although psychotic experiences are relatively common, those that are severe and distressing are linked to an increased risk of developing a psychotic disorder. This study aimed to investigate the association between the frequency of cannabis use and psychotic experiences in young adults. Methods 1034 U.S. college students completed questionnaires to assess: cannabis use in the past week, delusional ideation (Peters Delusions Inventory), hallucinations (Launay-Slade Hallucinations Scale-Extended), and depression (Beck Depression Inventory). Results Participants reporting higher rates of weekly cannabis use were more likely to report hallucinatory experiences and delusional ideation. The relationship between cannabis use and hallucinatory experiences, but not the relationship between cannabis use and delusional ideation, remained significant after controlling for levels of depression. Moreover, those who reported greater amounts of cannabis use had more distressing delusional ideas, that were held with more conviction. Conclusions Cannabis use is linked to the presence of subclinical hallucinations and delusional ideation in U.S. college students.

Cannabis is known to produce acute, transient psychotic-like experiences. However, it is unclear whether cannabis disproportionately increases the risk of specific types of psychotic experiences and whether genetic predisposition influences the relationship between cannabis use and psychotic experiences. In this cross-sectional study of 109,308 UK Biobank participants, we examined how schizophrenia polygenic risk modulates the association between self-reported cannabis use and four types of self-reported psychotic experiences (auditory hallucinations, visual hallucinations, persecutory delusions, and delusions of reference). Cohort-wide, we found a strong, dose-dependent relationship between cannabis use and all four types of psychotic experiences, especially persecutory delusions. Cannabis users’ psychotic experiences tended to be earlier-onset and cause greater distress than non-users’, but were not more likely to lead to help-seeking. Participants with high schizophrenia polygenic risk scores showed stronger associations between cannabis use and auditory hallucinations, visual hallucinations, and delusions of reference, as well as psychotic experiences overall. For instance, cannabis ever-use was associated with 67% greater adjusted odds of delusions of reference among individuals in the top fifth of polygenic risk, but only 7% greater adjusted odds among the bottom fifth. Our results suggest that cannabis use is a predictive risk factor for psychotic experiences, including early-onset and distressing experiences. Individuals genetically predisposed to schizophrenia may be especially vulnerable to psychotic experiences as a result of using cannabis, supporting a long-postulated hypothesis. This study exemplifies the utility of population-scale biobanks for elucidating gene-by-environment interactions relating substance use to neuropsychiatric outcomes and points to the translational potential of using polygenic risk scores to inform personalized harm reduction interventions.

This article introduces to the dermatology provider two medications for the treatment of tardive dyskinesia (TD), which were the first medications approved by the US FDA specifically for the treatment of TD. In addition to describing these two new medications, this article will also provide a focused review of the pathogenesis of TD, as well as non-FDA-approved treatments, which have been tried prior to the advent of these medications.A PubMed search was conducted and articles were reviewed by the senior authors and included if they were relevant for dermatologists regarding etiology, symptoms, risk, and treatment of TD.One of the most widely accepted explanations of TD involves the concept of 'dopamine receptor hypersensitivity state.' There are several other less well substantiated proposed pathogenic pathways of TD. The clinical manifestation is characterized by involuntary movements. Prevention includes switching to a 2nd generation agent or using the lowest dose possible for the shortest amount of time. Two new FDA-approved medications for TD are also discussed and reviewed.TD now has FDA-approved medications for treatment. Now, there is even more reason for the dermatologist to have increased confidence when treating delusions of parasitosis (DOP) with antipsychotic agents.

Ideas of reference (IOR) are often implicated in predicting psychosis onset. They have been conceptualized to present on a continuum, from oversensitive psychological reactions to delusional thoughts. It is however unknown to what extent IOR may be triggered by collective environmental stress. We obtained timely data from 9873 individuals to assess IOR in relation to trauma exposure in the 2019–2020 social unrest in Hong Kong. Two levels of IOR are distinguished: attenuated IOR (IOR-A), being the experience of feeling particularly referred to within a group; and exclusive IOR (IOR-E), the experience of feeling exclusively referred to while others are not. Logistic regressions showed that event-based rumination was a shared predictor for IOR-A (OR = 1.07, CI = 1.03–1.10) and IOR-E (OR = 1.09, CI = 1.02–1.17). For IOR-A, three categories of social unrest-related traumatic events (TEs) were significant predictors, including being attacked or having experienced sexual violence (OR = 4.14, CI = 1.93–8.85), being arrested (OR = 4.48, CI = 1.99–10.10), and being verbally abused (OR = 2.66, CI = 1.28–5.53). Being arrested was significant for IOR-E (OR = 3.87, CI = 1.03–14.52), though not when rumination was included. Education level also significantly predicted IOR-E (OR = 0.72, CI = 0.52–0.99). Further analysis revealed that rumination significantly mediated between TEs and IOR severity (β = 0.26, SE = 0.01, CI = 0.24–0.28). The findings are consistent with the hypothesis that IOR-A and IOR-E occur as levels on a continuum, but each has some distinctive correlates. Extrinsic events may play a more prominent role in IOR-A, while intrinsic factors, such as cognitive capacity, may play a more prominent role in IOR-E. The involvement of rumination across the IOR spectrum suggests an opportunity for intervention.

This study was funded by the Medical Research Council, the European Community’s Seventh Framework Program grant [agreement HEALTH-F2-2009-241909 (Project EU-GEI)], São Paulo Research Foundation (grant 2012/0417-0), the National Institute for Health Research (NIHR) Biomedical Research Centre (BRC) at South London and Maudsley NHS Foundation Trust and King’s College London, the NIHR BRC at University College London and the Wellcome Trust (grant 101272/Z/12/Z)., Tripoli, G., Quattrone, D., Ferraro, L., Gayer-Anderson, C., Rodriguez, V., La Cascia, C., La Barbera, D., Sartorio, C., Seminerio, F., Tarricone, I., Berardi, D., Szöke, A., Arango, C., Tortelli, A., Llorca, P.-M., De Haan, L., Velthorst, E., Bobes, J., Bernardo, M., Sanjuán, J., Santos, J.L., Arrojo, M., Del-Ben, C.M., Menezes, P.R., Selten, J.-P., Jones, P.B., Jongsma, H.E., Kirkbride, J.B., Lasalvia, A., Tosato, S., Richards, A., O'donovan, M., Rutten, B.P.F., Os, J.V., Morgan, C., Sham, P.C., Murray, R.M., Murray, G.K., Di Forti, M.

Objectives: When presenting with a first episode of psychosis (FEP), migrants can have different demographic and clinical characteristics to the native-born population and this was examined in an Irish Early Intervention for Psychosis service. Methods: All cases of treated FEP from three local mental health services within a defined catchment area were included. Psychotic disorder diagnoses were determined using the SCID and symptom and functioning domains were measured using validated and reliable measures. Results: From a cohort of 612 people, 21.1% were first-generation migrants and there was no difference in the demographic characteristics, diagnoses, symptoms or functioning between migrants and those born in the Republic of Ireland, except that migrants from Africa presented with less insight. Of those admitted, 48.6% of admissions for migrants were involuntary compared to 37.7% for the native-born population (p = 0.09). Conclusions: First-generation migrants now make up a significant proportion of people presenting with a FEP to an Irish EI for psychosis service. Broadly the demographic and clinical characteristics of migrants and those born in the Republic of Ireland are similar, except for less insight in migrants from Africa and a trend for a higher proportion of involuntary admissions in the total migrant group.

Among neurocognitive accounts of delusions, there is a growing consensus that it is the certainty with which delusions are held, rather than their content that defines some beliefs as delusional. On a continuum model of psychosis, this inappropriate certainty ought to be present (albeit in an attenuated form) in healthy adults who score highly in schizotypy. It was hypothesised that this might be most evident in circumstances where the environment provides incomplete or probabilistic information, which thereby forces the participant to hold two imperfectly supported, concurrent hypotheses in mind. A cued visual search task was used to measure people’s capacity to use partially predictive information (i.e., a cue that predicted the target may occur in one of the two locations) to facilitate speeded responding. As hypothesised, people’s performance on the trials that required holding two hypotheses in mind concurrently was significantly and specifically associated with the positive components of schizotypy. This finding is consistent with a hyperfocusing of attention in schizophrenia, and may help explain why delusion-prone individuals have a tendency to “jump to conclusions” or be resistant to disconfirming information when faced with multiple, partially supported hypotheses.

Cotard syndrome is a clinical condition defined by the presence of nihilistic delusions. We report two patients with Cotard syndrome in whom anti-NMDAR encephalitis (ANMDARE) was confirmed. Both cases showed features of affective psychosis, developed catatonic syndrome, and worsened after the use of antipsychotics. 18F-FDG PET brain studies showed a bilateral hemispheric pattern of hypometabolism in posterior regions, mainly in the cingulate cortex and in the medial aspects of parietal and occipital lobes. A more severe hypometabolism was observed in the right hemisphere of both patients. Both cases remitted with the use of specific immunotherapy for ANMDARE.

Sleep-related problems are prevalent in patients with psychotic disorders, yet their contribution to fluctuations in delusional experiences is less clear. This study combined actigraphy and experience-sampling methodology (ESM) to capture the relation between sleep and next-day persecutory symptoms in patients with psychosis and prevailing delusions. Individuals with current persecutory delusions (PD; n = 67) and healthy controls (HC; n = 39) were assessed over 6 consecutive days. Objective sleep and circadian rhythm measures were assessed using actigraphy. Every morning upon awakening, subjective sleep quality was measured using ESM. Momentary assessments of affect and persecutory symptoms were gathered at 10 random time points each day using ESM. Robust linear mixed modeling was performed to assess the predictive value of sleep measures on affect and daytime persecutory symptoms. PD showed significantly lower scores for subjective quality of sleep but significantly higher actigraphic-measured sleep duration and efficiency compared with HC. Circadian rhythm disruption was associated with more pronounced severity of persecutory symptoms in HC. Low actigraphy-derived sleep efficiency was predictive of next-day persecutory symptoms in the combined sample. Negative affect was partly associated with sleep measures and persecutory symptoms. Our results imply an immediate relationship between disrupted sleep and persecutory symptoms in day-to-day life. They also emphasize the relevance of circadian rhythm disruption for persecutory symptoms. Therapeutic interventions that aim to reduce persecutory symptoms could benefit from including modules aimed at improving sleep efficacy, stabilizing sleep-wake patterns, and reducing negative affect. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The existential crisis of nihilism in schizophrenia has been reported since the early days of psychiatry. Taking first-person accounts concerning nihilistic experiences of both the self and the world as vantage point, we aim to develop a dynamic existential model of the pathological development of existential nihilism. Since the phenomenology of such a crisis is intrinsically subjective, we especially take the immediate and pre-reflective first-person perspective’s (FPP) experience (instead of objectified symptoms and diagnoses) of schizophrenia into consideration. The hereby developed existential model consists of 3 conceptualized stages that are nested into each other, which defines what we mean by existential. At the same time, the model intrinsically converges with the phenomenological concept of the self-world structure notable inside our existential framework. Regarding the 3 individual stages, we suggest that the onset or first stage of nihilistic pathogenesis is reflected by phenomenological solipsism, that is, a general disruption of the FPP experience. Paradigmatically, this initial disruption contains the well-known crisis of common sense in schizophrenia. The following second stage of epistemological solipsism negatively affects all possible perspectives of experience, that is, the first-, second-, and third-person perspectives of subjectivity. Therefore, within the second stage, solipsism expands from a disruption of immediate and pre-reflective experience (first stage) to a disruption of reflective experience and principal knowledge (second stage), as mirrored in abnormal epistemological limitations of principal knowledge. Finally, the experience of the annihilation of healthy self-consciousness into the ultimate collapse of the individual’s existence defines the third stage. The schizophrenic individual consequently loses her/his vital experience since the intentional structure of consciousness including any sense of reality breaks down. Such a descriptive-interpretative existential model of nihilism in schizophrenia may ultimately serve as input for future psychopathological investigations of nihilism in general, including, for instance, its manifestation in depression.

Background: Depressive disorders, despite being classified as mood or affective disorders, are known to include disturbances in the experience of body, space, time, and intersubjectivity. However, current diagnostic manuals largely ignore these aspects of depressive experience. In this article, we use phenomenological accounts of embodiment as a theoretical foundation for a qualitative study of abnormal body phenomena (ABP) in depressive disorders. Methods: 550 patients affected by schizophrenic and affective disorders were interviewed in a clinical setting. Interviews sought to uncover the qualitative features of experiences through self-descriptions. Clinical files were subsequently digitized and re-examined using consensual qualitative research. Results: Ninety-nine out of 100 patients with MDD reported at least one ABP. From cross-analysis of the MDD sample, we obtained 4 general categories of ABP, 3 of which had additional subcategories. The 4 categories include slowed embodied temporality (N = 90), anomalous vital rhythms (N = 82), worries about one’s body (N = 22), and body deformation (N = 47). Conclusions: The results provide empirical evidence in support of theoretical discussions of embodiment in MDD found in the work of classical and contemporary phenomenologists. The findings also provide nuanced insight into the experience of persons living with MDD. Some categories of ABP, like slowed embodied temporality, can help to finely characterize psychomotor retardation or the so-called “medically unexplained symptoms” (MUS). This fine-tuned characterization can help to connect MUS to neuropsychological and neurobiological (e.g., alterations of interoceptive processes linked to anomalies of the brain resting-state hypothesis) and inflammatory (e.g., studies linking environmental stressors, inflammation mediators, and neurovegetative and affective symptoms) models of MDD. Our results can also support a pathogenic model of MDD, which posits, on the phenomenal level, ABP as the point of departure for the development of secondary symptoms including cognitive elaborations of these, namely, delusions about the body. Moreover, some of the categories, when contrasted with phenomenological qualitative studies of other disorders, provide conceptual resources of differential diagnosis and of identifying a “depressive core syndrome.” For example, findings within category 4, deformation of the body, provide resources for using ABP to distinguish between MDD and schizophrenia.

Prevailing models of psychosis risk incorporate positive subthreshold symptoms as defining features of risk or transition to psychotic disorders. Despite this, relatively few studies have focused on characterizing longitudinal symptom features, such as prevalence, concordance and structure, which may aid in refining methods and enhancing classification and prediction efforts. The present study aimed to fill these gaps using longitudinal 24-month follow-up data from the well-characterized NAPLS-2 multi-site investigation of youth at clinical high risk (CHR) who had (n = 86) and had not (n = 268) transitioned to a threshold psychotic disorder since baseline. At baseline, among sub-delusional ideas, unusual thought content and suspicious/persecutory thinking were very common in CHR youth, and were highly concordant. Perceptual abnormalities (P4) were also common across youth regardless of symptom course and eventual transition to psychosis. Grandiose ideas were rare. Exploratory factor analysis extracted two constituent factors at multiple follow-up intervals, but there was marked instability in the structure over 24 months, and clear indicators for a single positive symptom factor. Together these findings support suggestions to combine sub-delusional symptoms into a single symptom category for classification purposes, in efforts to reduce clinical heterogeneity and ease measurement burden.

Background: Comprehensive clinicopathological studies of neuropsychiatric symptoms (NPS) in dementia are lacking. Objective: To describe the pathological correlations of NPS in a sample of institutionalized people with dementia. Methods: We studied 59 people who were consecutively admitted to a nursing home and donated their brain. Correlations between pathological variables and NPS upon admission (n = 59) and at one-year follow-up assessment (n = 46) were explored and confirmed using bivariate and multivariate statistical methods. Results: Mean (SD) age at admission was 83.2 (6.4) years and mean (SD) age at demise was 85.4 (6.6); 73% of the subjects were female and 98% presented advanced dementia. The most frequent etiological diagnosis was Alzheimer’s disease (AD; 74.6% clinical diagnosis, 67.8% pathological diagnosis). The pathological diagnosis of AD was associated with aggression (β est 0.31), depression (β est 0.31), anxiety (β est 0.38), and irritability (β est 0.28). Tau stage correlated with aggressive symptoms (β est 0.32) and anxiety (βest 0.33). Coexistence of AD and Lewy body pathology was associated with depression (β est 0.32), while argyrophilic grains were associated with eating symptoms (β est 0.29). Predictive models were achieved for apathy, including cognitive performance, basal ganglia ischemic lesions, and sex as predictors (R2 0.38) and for sleep disorders, including pathological diagnosis of AD and age at demise (R2 0.18) (all p-values

Auditory-verbal hallucinations (AVH) are a key symptom of schizophrenia. Recent neuroimaging studies examining dynamic functional connectivity suggest that disrupted dynamic interactions between brain networks characterize complex symptoms in mental illness including schizophrenia. Studying dynamic connectivity may be especially relevant for hallucinations, given their fluctuating phenomenology. Indeed, it remains unknown whether AVH in schizophrenia are directly related to altered dynamic connectivity within and between key brain networks involved in auditory perception and language, emotion processing, and top-down control. In this study, we used dynamic connectivity approaches including sliding window and k-means to examine dynamic interactions among brain networks in schizophrenia patients with and without a recent history of AVH. Dynamic brain network analysis revealed that patients with AVH spent less time in a ‘network-antagonistic’ brain state where the default mode network (DMN) and the language network were anti-correlated, and had lower probability to switch into this brain state. Moreover, patients with AVH showed a lower connectivity within the language network and the auditory network, and lower connectivity was observed between the executive control and the language networks in certain dynamic states. Our study provides the first neuroimaging evidence of altered dynamic brain networks for understanding neural mechanisms of AVH in schizophrenia. The findings may inform and further strengthen cognitive models of AVH that aid the development of new coping strategies for patients. Electronic supplementary material The online version of this article (10.1007/s00429-020-02119-1) contains supplementary material, which is available to authorized users.

BackgroundThere is evidence that environmental and genetic risk factors for schizophrenia spectrum disorders are transdiagnostic and mediated in part through a generic pathway of affective dysregulation.MethodsWe analysed to what degree the impact of schizophrenia polygenic risk (PRS-SZ) and childhood adversity (CA) on psychosis outcomes was contingent on co-presence of affective dysregulation, defined as significant depressive symptoms, in (i) NEMESIS-2 (n = 6646), a representative general population sample, interviewed four times over nine years and (ii) EUGEI (n = 4068) a sample of patients with schizophrenia spectrum disorder, the siblings of these patients and controls.ResultsThe impact of PRS-SZ on psychosis showed significant dependence on co-presence of affective dysregulation in NEMESIS-2 [relative excess risk due to interaction (RERI): 1.01, p = 0.037] and in EUGEI (RERI = 3.39, p = 0.048). This was particularly evident for delusional ideation (NEMESIS-2: RERI = 1.74, p = 0.003; EUGEI: RERI = 4.16, p = 0.019) and not for hallucinatory experiences (NEMESIS-2: RERI = 0.65, p = 0.284; EUGEI: −0.37, p = 0.547). A similar and stronger pattern of results was evident for CA (RERI delusions and hallucinations: NEMESIS-2: 3.02, p < 0.001; EUGEI: 6.44, p < 0.001; RERI delusional ideation: NEMESIS-2: 3.79, p < 0.001; EUGEI: 5.43, p = 0.001; RERI hallucinatory experiences: NEMESIS-2: 2.46, p < 0.001; EUGEI: 0.54, p = 0.465).ConclusionsThe results, and internal replication, suggest that the effects of known genetic and non-genetic risk factors for psychosis are mediated in part through an affective pathway, from which early states of delusional meaning may arise.

Individuals with neurocognitive disorders (NCD) frequently experience psychotic symptoms, such as delusions. Delusions can contribute to other behavior problems, create dangers for patients and caregivers, and contribute to inpatient hospitalization of individuals with NCD. The current study aimed to identify cognitive symptoms associated with the presence of delusions and to differentiate delusion types based on cognitive profiles among hospitalized older adults with NCD. A review of electronic medical records of hospitalized older adults from an inpatient geriatric psychiatry setting yielded 185 patients with a diagnosis of mild or major NCD who had a neuropsychological evaluation during their admission and whose documentation described a clear delusion. We identified a comparison group of 185 patients without delusions well matched for age, education, and sex, and similar in global cognitive status. Exclusion criteria included delirium and history of a psychotic disorder. We first compared the groups' performances on a dementia battery. Then, cognitive performances of subgroups with specific delusion types (harm, theft, jealousy, and misidentification) were each compared to the remainder of the delusion-positive group. Exploratory analyses revealed that the delusion-positive group had a greater rate of discontinuation on Trails B and performed worse than the delusion-negative group on Trails A, Behavioral Dyscontrol Scale, Semantic Fluency, and Hopkins Verbal Learning Test-Revised (HVLT-R) initial registration. Theft delusions were associated with worse performance on HVLT-R recognition, misidentification delusions were associated with worse performance on Trails B, and harm delusions were associated with worse performance on a verbal generativity test. The presence of delusions in hospitalized older adults with NCD was associated with worse performance on several cognitive tasks with many being suggestive of associated with frontal-subcortical network integrity. Delusions of theft may be a consequence of reduced integrity of medial temporal lobe memory system.

Cotard's syndrome usually presents as combined symptoms occurring in a broad series of neurological, psychiatric, and medical disorders, being severe depression the most frequent. The syndrome is not classified as a distinct clinical entity in the nosological systems but appears solely as a clinical condition in case reports. Thus, the diagnosis of Cotard's syndrome mainly centres on the psychiatric interview and the ability of the clinician to recognise specific symptoms due to the absence of both clinical instruments and diagnostic criteria. Cotard's syndrome has never been described to date in patients with a history of obsessive-compulsive disorder (OCD). We report a case of a 49-year-old woman presenting obsessive symptoms and related compulsions for more than 30 years. Cotard's syndrome appeared after 3 years from a tragic event that had caused a psychological trauma. Such an occurrence may have contributed to worsening OCD and leading to a second major depressive episode followed by a suicidal attempt. Since then, the subject of our patient's obsessive thoughts changed, and the belief of being dead appeared. The repetitive and stereotyped thoughts caused severe distress, and accompanied the compulsive nature of reassurance seeking, temporarily beneficial to the anxiety arousing. The transition from obsession to delusion occurred when resistance was abandoned, and insight was lost. Once Cotard's syndrome had stabilised, OCD was no longer present. Additional distinctive features were the absence of psychiatric family history and the persistent nature of the affective psychosis. We concluded that Cotard's syndrome represented the evolution of the initial obsessive-compulsive disorder. Furthermore, we differentiated the clinical condition of our patient from other psychiatric diseases with similar clinical features. Larger-scale research is needed to consider topics other than comorbidity and also to explore significant elements of the patient's clinical history to discover what may influence the evolution and/or the persistence of the diseases.

Here we describe a rare case of Capgras delusion - a misidentification syndrome characterized by the belief that a person has been replaced by an imposter - in a patient without evident neurological or psychiatric symptoms. Intriguingly, delusional belief was selective for both person and modality, as the patient believed that his son - not his daughter or other relatives - was substituted with an imposter only while being in presence of him and looking at his face, but not when merely listening to his voice. A neuroanatomical reconstruction obtained integrating morphological and functional patient's neuroimaging data highlighted two main peculiarities: a compression of the rostral portion of right temporal lobe due to a large arachnoid cyst, and a bilaterally reduced metabolism of frontal areas. Autonomic data obtained from thermal infra-red camera and skin conductance recordings showed that a higher sympathetic activation was evoked by the observation of daughter's face, relative to the observation of the son's face as well as of not-familiar faces; conversely, daughter and son voices elicited a similar sympathetic activation, higher relative to not-familiar voices, indicating a modality-dependent dissociation consistent with the delusional behavior. Our case supports the "two-hit hypothesis" about Capgras delusion etiopathogenesis: here, the first hit is represented by the right-temporal lesion impairing the association between familiar faces and emotional values, the second one is the frontal bilateral hypometabolism favoring delusional behavior. The selective occurrence of "imposter" delusion for a particular subject and for a specific perceptual modality suggests the involvement of modality-specific interactions in the retrieval of affective properties during familiar people recognition.

Schizophrenia is correlated with religious delusions but, heretofore, the relationship between schizophrenia prevalence and religiosity has not been explored at the national level. Examining this relationship, we find that national level schizophrenia prevalence is correlated with national level religiosity and strongly negatively correlated with national level atheism across 125 countries. When controlling for cognitive performance and economic development in multiple regression analyses, the proportion of the variance explained was 2.9% (p p

Despite being an infrequent crime, parental homicide has been associated with schizophrenia spectrum disorders in adult perpetrators and a history of child abuse and family violence in adolescent perpetrators. Among severe psychiatric disorders there is initial evidence that delusional misidentification might also play a role in parricide. Parricides are often committed with undue violence and may result in overkill. The authors present the case of an adult male affected by schizoaffective disorder and Capgras syndrome who committed patricide. Forensic pathologists classify such cases as overkill by multiple fatal means comprising stabbing, blunt trauma and choking. Accurate crime scene investigations coupled with psychiatric examinations of perpetrator allow reconstruction of the murder stages. This overkill case is discussed in the context of a broad review of the literature.

While psychotic experiences are core symptoms of mental health disorders like schizophrenia, they are also reported by 5–10% of the population. Both smoking behaviour and genetic risk for psychiatric disorders have been associated with psychotic experiences, but the interplay between these factors remains poorly understood. We tested whether smoking status, maternal smoking around birth, and number of packs smoked/year were associated with lifetime occurrence of three psychotic experiences phenotypes: delusions (n = 2067), hallucinations (n = 6689), and any psychotic experience (delusions or hallucinations; n = 7803) in 157,366 UK Biobank participants. We next calculated polygenic risk scores for schizophrenia (PRSSCZ), bipolar disorder (PRSBP), major depression (PRSDEP) and attention deficit hyperactivity disorder (PRSADHD) in 144,818 UK Biobank participants of European ancestry to assess whether association between smoking and psychotic experiences was attenuated after adjustment of diagnosis of psychiatric disorders and the PRSs. Finally, we investigated whether smoking exacerbates the effects of genetic predisposition on the psychotic phenotypes in gene-environment interaction models. Smoking status, maternal smoking, and number of packs smoked/year were associated with psychotic experiences (p −5). Except for packs smoked/year, effects were attenuated but remained significant after adjustment for diagnosis of psychiatric disorders and PRSs (p −3). Gene-environment interaction models showed the effects of PRSDEP and PRSADHD (but not PRSSCZ or PRSBP) on delusions (but not hallucinations) were significantly greater in current smokers compared to never smokers (p

The impact of the COVID-19 pandemic on psychosis remains to be established. Here we report 6 cases (3 male and 3 female) of first-episode psychosis (FEP) admitted to our hospital in the second month of national lockdown. All patients underwent routine laboratory tests and a standardized assessment of psychopathology. Hospitalization was required due to the severity of behavioral abnormalities in the context of a full-blown psychosis (the Brief Psychiatric Rating Scale [BPRS] = 75.8 ± 14.6). Blood tests, toxicological urine screening, and brain imaging were unremarkable, with the exception of a mild cortical atrophy in the eldest patient (male, 73 years). All patients were negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) throughout their stay, but 3 presented the somatic delusion of being infected. Of note, all 6 cases had religious/spiritual delusions and hallucinatory contents. Despite a generally advanced age (53.3 ± 15.6), all patients had a negative psychiatric history. Rapid discharge (length of stay = 13.8 ± 6.9) with remission of symptoms (BPRS = 27.5 ± 3.1) and satisfactory insight were possible after relatively low-dose antipsychotic treatment (Olanzapine-equivalents = 10.1 ± 5.1 mg). Brief psychotic disorder/acute and transient psychotic disorder diagnoses were confirmed during follow-up visits in all 6 cases. The youngest patient (female, 23 years) also satisfied the available criteria for brief limited intermittent psychotic symptoms. Although research on larger populations is necessary, our preliminary observation suggests that intense psychosocial stress associated with a novel, potentially fatal disease and national lockdown restrictions might be a trigger for FEP.

Various studies have demonstrated associations between personality disorders and relationship satisfaction. The authors examine the associations between attention seeking and grandiosity, both features of narcissistic personality disorder, and relationship satisfaction before and after the transition to parenthood. The authors then expand their analysis to parental satisfaction and postpartum depression (PPD). Nonclinical couples (N = 103 couples) expecting their first child completed measures of grandiosity, attention seeking, and relationship satisfaction before birth, and of relationship satisfaction, parental satisfaction, and PPD symptoms 3 months afterward. Attention seeking was associated with less parental satisfaction and more PPD symptoms, and with less prepartum relationship satisfaction for participants' partners. For men, attention seeking was also associated with prepartum relationship satisfaction. Grandiosity was associated with a decrease in relationship satisfaction after birth, although, surprisingly with fewer PPD symptoms for participants’ partners. The authors discuss how these findings might be related to changes in social support and work–life balance during the transition to parenthood.

Repetitive transcranial magnetic stimulation (rTMS), when applied to left dorsolateral prefrontal cortex (LDLPFC), reduces negative symptoms of schizophrenia, but has no effect on positive symptoms. In a small number of cases, it appears to worsen the severity of positive symptoms. It has been hypothesized that high-frequency rTMS of the LDLPFC might increase the dopaminergic neurotransmission by driving the activity of the left striatum in the basal ganglia (LSTR)—increasing striatal dopaminergic activity. This hypothesis relies on the assumption that either the frontal–striatal connection or the intrinsic frontal and/or striatal connections covary with the severity of positive symptoms. The current work aimed to evaluate this assumption by studying the association between positive and negative symptoms severity and the effective connectivity within the frontal and striatal network using dynamic causal modeling of resting state fMRI in a sample of 19 first episode psychosis subjects. We found that the total score of positive symptoms of schizophrenia is strongly associated with the frontostriatal circuitry. Stronger intrinsic inhibitory tone of LDLPFC and LSTR, as well as decreased bidirectional excitatory influence between the LDLPFC and the LSTR is related to the severity of positive symptoms, especially delusions. We interpret that an increase in striatal dopaminergic tone that underlies positive symptoms is likely associated with increased prefrontal inhibitory tone, strengthening the frontostriatal ‘brake’. Furthermore, based on our model, we propose that lessening of positive symptoms could be achieved by means of continuous theta-burst or low-frequency (1 Hz) rTMS of the prefrontal area.

Experimental research has shown that poor sleep triggers psychotic experiences, even in healthy participants. This warrants an in-depth investigation of this mechanism in a naturalistic environment, an exploration of which particular aspects of poor sleep trigger psychotic symptoms, and a test for reverse effects of symptoms on sleep. For this purpose, we conducted a 14-day ambulatory assessment study with 82 young adults (age: M = 21.24 years, SD = 1.54; 64.6% female), half of which were characterized by elevated psychosis proneness. Objective sleep parameters (actigraphically-measured sleep time, wake after sleep onset, sleep efficiency), self-reported sleep parameters (feeling rested, dream recall, dream valence), and psychotic symptoms (paranoid symptoms, hallucinatory experiences) were assessed once per day. Using multilevel regressions (928 data points), we found that shorter sleep time and negative dream valence predicted paranoid symptoms, whereas feeling less rested and dream recall predicted hallucinatory experiences. In participants with elevated psychosis proneness, associations with the aforementioned sleep parameters were increased for hallucinatory experiences but not for paranoid symptoms. Finally, we found bidirectional associations between poor sleep and paranoid symptoms but only unidirectional associations between poor sleep and hallucinatory experiences. The findings corroborate the relevance of sleep disturbance as a predictor of psychotic experiences. Future studies should further investigate the potential of sleep interventions to prevent psychotic symptoms and disorders.