The Arabic Questionnaire for Psychotic Experiences in patients with psychotic disorders: a clinical validation.

BACKGROUND: Psychotic experiences are reported in the general population. The Questionnaire for Psychotic Experiences (QPE) was created to test the phenomenological features of these experiences and compare them with those reported in patients with psychiatric and other medical conditions. The aim of this study was to test the psychometric properties of the Arabic version of the QPE. METHODS: We recruited 50 patients with psychotic disorders from the Hamad Medical Hospital in Doha, Qatar. Patients underwent assessment over three sessions with trained interviewees using the Arabic versions of QPE, Positive and Negative Syndrome Scale (PANSS), Beck Depression Inventory (BDI), and the Global Assessment of Functioning Scale (GAF). Patients were also reassessed using the QPE and GAF after 14-days from the initial assessment in order to test for the stability of the scale. In this respect, this is the first study that assesses the test-retest reliability of the QPE. The psychometric properties including convergent validity, stability, and internal consistency met the benchmarked criteria. RESULTS: Results confirmed that the Arabic version of QPE accurately measured the experiences of patients that were also reported using the PANSS, an internationally accepted, well-established scale for measuring psychotic symptom severity. CONCLUSION: We propose the use of the QPE to describe the phenomenology of PEs across modalities in Arabic speaking communities.

Mapping psychotic-like experiences: Results from an online survey.

Suggestions have been made that psychotic-like experiences (PLEs), such as hallucinatory and delusional experiences, exist on a continuum from healthy individuals to patients with a diagnosis of schizophrenia. We used the screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an online survey in a sample of more than 1,400 participants, we demonstrated that the QPE screening questions show satisfactory psychometric properties. Participants with mental disorders reported more frequent lifetime and current hallucinatory experiences than participants without mental disorders. Childhood experiences were rather low and ranged from 0.7% to 5.2%. We further replicated findings that young age, illegal drug use, lower level of education, and having parents with a mental disorder are associated with higher endorsement rates of PLEs. Finally, a binomial regression revealed that the mere presence of PLEs does not discriminate between individuals with and without a mental disorder. Taken together, the findings of the present study support existing models that both hallucinations and delusions exist on a structural and phenomenological continuum. Moreover, we demonstrated that the QPE screening questions can be used by themselves as a complementary tool to the full QPE interview.

Hallucinations and other psychotic experiences across diagnoses: A comparison of phenomenological features.

Although psychotic experiences are prevalent across many psychiatric, neurological, and medical disorders, investigation of these symptoms has largely been restricted to diagnostic categories. This study aims to examine phenomenological similarities and differences across a range of diagnoses. We assessed frequency, severity and phenomenology of psychotic experiences in 350 outpatients including; participants with schizophrenia spectrum disorders, hearing impairment, Parkinson's disease, Lewy Body Dementia, Alzheimer's disease, visual impairment, posttraumatic stress disorder, borderline personality disorder, and participants with recent major surgery. Psychotic phenomena were explored between these groups using the Questionnaire for Psychotic Experiences (QPE). Participants with major psychiatric disorders reported a combination of several psychotic experiences, and more severe experiences compared to all other disorders. Participants with recent major surgery or visual impairment experienced isolated visual hallucinations. Participants with hearing impairment reported isolated auditory hallucinations, whereas the neurodegenerative disorders reported visual hallucinations, occasionally in combination with hallucinations in another modality or delusions. The phenomenology between neurodegenerative disorders, and within major psychiatric disorders showed many similarities. Our findings indicate that the phenomenology of psychotic experiences is not diagnosis specific, but may rather point to the existence of various subtypes across diagnoses. These subtypes could have a different underlying etiology requiring specific treatment.