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.