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Psychotic experiences are prevalent across a wide variety of psychiatric, neurological, and medical conditions. Yet current assessments are often designed for one disorder, or are limited in their examination of phenomenological features; this has hindered transdiagnostic research. This article describes an examination of the validity and reliability of the English version of a new assessment, the Questionnaire for Psychotic Experiences (QPE). This study aimed to use the QPE to examine hallucinations and delusions across a number of different conditions, and to ensure that the QPE had acceptable psychometric properties. An International Consortium on Hallucination Research working group, along with consumer groups, developed the 50-item QPE to assess the presence, severity, and phenomenology of hallucinations and delusions. Participants in the study who reported psychotic experiences included those with schizophrenia, schizoaffective disorder, bipolar affective disorder, and major depressive disorder, and those without a need for care (ie, nonclinical participants). There were 173 participants in total. Convergent and discriminant validity were assessed. Reliability was examined in terms of stability, equivalence, and internal consistency. The data confirmed that the QPE had good psychometric properties and could be put forward as an accepted measure of the transdiagnostic evaluation of psychotic experiences. Further validation is recommended with neurological and medical populations. Given its validity and reliability, comprehensive evaluation of psychotic phenomena, and relatively quick administration time, we propose that the QPE is a valuable instrument for both clinical and research settings.

Hallucinations in patients with borderline personality disorder: characteristics, severity, and relationship with schizotypy and loneliness Slotema CW, Bayrak H, Linszen MMJ, Deen M, Sommer IEC. Hallucinations in patients with borderline personality disorder: characteristics, severity, and relationship with schizotypy and loneliness.Objective: In patients with borderline personality disorder (BPD), data are lacking on characteristics and severity of hallucinations in modalities other than the auditory (verbal) type. The same applies to relationships between hallucinations and the severity of depression, anxiety, schizotypy, and loneliness. Methods: In 60 female patients with BPD (37 also with hallucinations), this cross-sectional study explored characteristics and severity of (i) hallucinations and (ii) schizotypal features, (iii) severity of depression and anxiety, and (iv) loneliness, and the relationships between hallucinations and the other characteristics. Results: In patients with hallucinations, 80% experienced hallucinations in more than one modality; in the different modalities, the characteristics of the hallucinations were similar. The criteria for loneliness were fulfilled in 81% and 48% of patients with and without hallucinations. Compared to patients with BPD without hallucinations, the presence of hallucinations was associated with higher scores for depression, anxiety, loneliness, and schizotypy. Furthermore, the severity of hallucinations showed a positive correlation with the severity of loneliness and schizotypy. Conclusion: Patients with BPD experienced hallucinations with characteristics similar to the more frequently studied auditory (verbal) hallucinations. Higher scores for schizotypy and loneliness indicate that patients with hallucinations had more characteristics of cluster A personality disorders. Significant outcomes• In patients with hallucinations, 80% experienced hallucinations in more than one modality and the characteristics of these hallucinations were similar across the different modalities.• The criteria for loneliness were fulfilled in 81% of patients with hallucinations and in 48% of patients without hallucinations.• Compared to patients without hallucinations, the presence of hallucinations was associated with higher scores for the three clusters of schizotypy. Limitations• Since this study has a cross-sectional design, no assumptions can be made regarding causality.• Also, the study population was of only moderate size.• In most patients, the presence of a schizotypal personality disorder was explored by means of the DSM-5 criteria, without the use of a structured clinical interview.