Development and Validation of the MAPE: A Self-Report Questionnaire Measuring In-the-Moment Psychotic Symptoms Across the Continuum

Psychotic symptoms are dynamic, yet traditional assessments often measure them retrospectively and at single timepoints, potentially missing clinically meaningful symptom variability. Further, many measures are population-specific, limiting their use across the psychosis continuum. To address these gaps, we developed the Momentary Assessment of Psychotic Experiences(MAPE), a brief self-report questionnaire measuring in-the-moment psychosis across the continuum. Validation was conducted across four community samples recruited via Prolific (N = 3,552) and one clinical sample with psychotic disorders (N = 73). The initial 56-item pool was reduced to 30 items through exploratory and confirmatory factor analyses in community samples. Internal consistency was examined across samples. Convergent validity was tested against the Paranoia Scale, Magical Ideation Scale, Revised Hallucinations Scale, and Revised Social Anhedonia Scale. Concurrent validity in the clinical sample was evaluated using the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms. Analyses identified five factors: unusual thoughts/sensory experiences, paranoia, amotivation/anhedonia, social anhedonia, and negative affect. This structure showed excellent fit and internal consistency in community samples, with comparable reliability in the clinical sample. MAPE subscales demonstrated moderate correlations with subclinical psychosis measures in community samples and interviewer-rated symptoms in the clinical sample. Findings support the MAPE as a valid and standardized measure of momentary psychotic experiences. By focusing on current state, the MAPE reduces retrospective bias and improves ecological validity. Designed for use across both subclinical and clinical populations, the MAPE also offers a unique tool for studying psychotic symptoms along the continuum.