| Epidemiological studies have demonstrated that the prevalence of psychotic disorders is exceeded by that of sub-threshold psychotic experiences, which are phenomenologically similar to threshold psychosis but of less intensity or associated impairment. Recent research has highlighted the potential clinical significance of psychotic experiences with regards to psychological distress, service utilization, psychiatric comorbidities, and suicide risk. The aims of this three paper dissertation are to: 1) determine risk for suicidal behavior among respondents with psychotic experiences; 2) examine the prevalence of psychotic experiences among respondents with common mental disorders, and describe the clinical significance of these symptoms when occurring in the context of common mental disorders; and 3) evaluate factors associated with the persistence or remission of psychotic experiences in the general population. For all three papers, data were drawn from the Collaborative Psychiatric Epidemiology Surveys (n=20,013), composed of the National Comorbidity Survey-Replication, National Latino and Asian American Study, and National Survey of American Life. Psychotic experiences and other clinical variables were assessed using the World Health Organization Composite International Diagnostic Interview, version 3.0. Analyses consisted primarily of logistic regression models, with effect sizes calculated as adjusted odds ratios. Psychotic experiences were found to be associated with elevated risk for suicidal ideation and suicide attempts, and with multiple co-morbidities with common mental health conditions. The persistence of psychotic experiences over time was primarily associated with the type of symptom experienced (i.e. hearing voices) and with marital status. Co-morbid mental health conditions, although extensive, did not predict the persistence of psychotic experiences, although persistent psychotic experiences were associated with ongoing suicide risk. Together, these data support the clinical significance of sub-threshold psychotic experiences among a large general population sample of adults in the United States. The most clinically notable features of psychotic experiences are that they indicate drastically elevated risk for suicide attempts (particularly severe attempts with intent to die) and the presence of multiple co-morbid mental health conditions. These findings will have clinical utility in highlighting unique needs of individuals with sub-threshold psychotic symptoms, and will have public health value in identifying a significant risk factor for severe suicidal behavior that may be easily screened in the general population as well as in clinical settings. |
