Measuring Psychotic-Like Experiences in the General Population.

Introduction: The notion of a full psychosis continuum in which psychosis is seen on a continuum with normal experience rests heavily on studies showing that psychotic symptoms are common in the general population. However, the methods of assessment in the studies have been criticized.

Objectives: (1) to investigate how many from the general population who answered positively on a psychotic-like symptoms questionnaire and (2) to clinically assess a subset of those with psychotic-like experiences (PLE).

Methods: A self-rating questionnaire concerning PLEs was given to individuals from the general population. A subsample of those, who scored positively for PLEs, was clinically assessed for psychosis.

Results: Totally, 5.7% of the participants rated positive for PLEs according to the self-rating questionnaire. Forty of these were clinically assessed and 7 (17.5%) of them were found to have had a psychotic experience, 4 of them were already in psychiatric treatment.

Conclusion: The self-reported psychotic-like phenomena were more common in the general population than psychotic disorders. However, when assessed clinically, the experienced phenomena did correspond to psychotic phenomena except in a few patients, who were found to suffer from a psychotic disorder. Overall, we did not find support for the full psychosis continuum model.