Investigation of the occurrence of psychotic symptoms in non-psychiatric population may help to identify population at risk of psychosis. The aim of our study was to find out lifetime and current prevalence of psychotic symptoms in the general population of the Czech Republic. Study sample consisted of a stratified population. All participants were administered the Psychosis Screening Questionnaire and the data on psychiatric treatment and diagnosis according to the M.I.N.I. were recorded. In total, 3244 subjects responded (48.1% males and 51.9% females). The most frequently reported symptom was paranoia (7.7%), followed by hypomania (6.2%), strange experiences (5.2%), thought insertion (3.8%), and hallucinations (1.7%). Lifetime prevalence of minimum 1 psychotic symptom was 17.9%. The highest proportion of responders reported only one symptom (13.5%). Significantly more males than females experienced paranoia (p=0.002). In the subset of individuals with a history of at least one psychotic symptom, 70.6% never visited a psychiatrist, 78.9% did not meet diagnostic criteria of psychotic disorder according to the M.I.N.I., and 67.0% failed to have any psychiatric diagnosis at all. The results suggest a high frequency of psychotic experience among the ethnically homogeneous Czech population. Only the longitudinal follow-up could confirm whether the symptomatic subjects are at risk of development of psychotic disorder. More likely, our findings support a hypothesis of the presence of psychiatric symptoms in the general population as a continuum of psychotic spectrum, from normality and sanity through unique psychotic experiences to fully expressed illness.

Supported by the research project CNS 1M0517.