The experience of felt presence in a general population sample.

Felt presence is a widely occurring experience, but remains under-recognised in clinical and research practice. To contribute to a wider recognition of the phenomenon, we aimed to assess the presentation of felt presence in a large population sample (n = 10 447) and explore its relation to key risk factors for psychosis. In our sample 1.6% reported experiencing felt presence in the past month. Felt presence was associated with visual and tactile hallucinations and delusion-like thinking; it was also associated with past occurrence of adverse events, loneliness and poor sleep. The occurrence of felt presence may function as a marker for general hallucination proneness.

Impacts of risk thresholds and age on clinical high risk for psychosis: a comparative network analysis.

One of the main goals for supporting people with a psychotic disorder is early detection and intervention, and the detection of Clinical High Risk (CHR) is a major challenge in this respect. This study sought to compare core symptoms of CHR for psychosis networks based on two CHR self-assessment tools, across different risk thresholds and age groups. This cross-sectional online investigation analyzed 936 individuals for CHR, in France and the UK, with the Prodromal Questionnaire-16 (PQ-16) and the Perceptual and Cognitive Aberrations (PCA). Twelve different symptom networks were constructed, assessing relationships, compactness, centrality, predictability, and comparisons between them, based on different thresholds and age groups. In the above-threshold PQ-16 network, the most central symptom was "Voices or whispers"; in the PCA network, the most central symptom was "Non-relevant thoughts distract or bother". They presented low overall predictability. No significant difference was found between them. This study makes three key contributions. First, this cross-network analyses highlight the relative importance of some central symptoms. Secondly, comparisons between networks demonstrate the unity of the CHR construct across scales, thresholds, and ages, affirming its phenotypic homogeneity, an essential issue for patient care pathways. Thirdly, the low average network predictability suggests the existence of unconsidered symptoms within these CHR networks. These results shed light on the organization of CHR symptoms using routine clinical questionnaires, offering insights for preventive targets in a logic of precision semiology.

Addressing the elephant in the screening room: an item response theory analysis of the Prodromal Questionnaire (PQ-16) for at-risk symptoms of psychosis.

OBJECTIVE: Within the context of patients at-risk of psychosis, where a variety of symptoms are present, identifying the most discriminative symptoms is essential for efficient detection and management. METHODS: This cross-sectional online study analyzed individuals from the general population in order to better assess their risk of presenting symptoms belonging to the clinical high risk (CHR) for psychosis, called "CHR-related symptoms". The Prodromal Questionnaire-16 (PQ-16) served as a self-report screening tool. Item response theory (IRT) with a graded response model was used to assess the discrimination and difficulty of its criteria. RESULTS: The analysis included 936 participants (mean age: 21.5 years; 28.1% male, 71.9% female). "Déjà vu" stood out for its high discriminative power, while "Voices or whispers" and "Seen things" demonstrated strong precision relatively to the other CHR-related symptoms. Conversely, "Smell or taste" and "Changing face" were associated with the most severe cases relatively to the other CHR-related symptoms. CONCLUSION: This study identified the most indicative CHR-related symptoms to emphasize their significance in accurately assessing severity and guiding targeted preventative interventions.

Effects of a novel, brief psychological therapy (Managing Unusual Sensory Experiences) for hallucinations in first episode psychosis (MUSE FEP): Findings from an exploratory randomised controlled trial.

Hallucinations are a common feature of psychosis, yet access to effective psychological treatment is limited. The Managing Unusual Sensory Experiences for First-Episode-Psychosis (MUSE-FEP) trial aimed to establish the feasibility and acceptability of a brief, hallucination-specific, digitally provided treatment, delivered by a non-specialist workforce for people with psychosis. MUSE uses psychoeducation about the causal mechanisms of hallucinations and tailored interventions to help a person understand and manage their experiences. We undertook a two-site, single-blind (rater) Randomised Controlled Trial and recruited 82 participants who were allocated 1:1 to MUSE and treatment as usual (TAU) (n = 40) or TAU alone (n = 42). Participants completed assessments before and after treatment (2 months), and at follow up (3-4 months). Information on recruitment rates, adherence, and completion of outcome assessments was collected. Analyses focussed on feasibility outcomes and initial estimates of intervention effects to inform a future trial. The trial is registered with the ISRCTN registry 16793301. Criteria for the feasibility of trial methodology and intervention delivery were met. The trial exceeded the recruitment target, had high retention rates (87.8%) at end of treatment, and at follow up (86.6%), with good acceptability of treatment. There were 3 serious adverse events in the therapy group, and 5 in the TAU group. Improvements were evident in both groups at the end of treatment and follow up, with a particular benefit in perceived recovery in the MUSE group. We showed it was feasible to increase access to psychological intervention but a definitive trial requires further changes to the trial design or treatment.