Psychotic-like experiences (PLEs) in the Hong Kong general population: pattern of change at two-year follow-up

Abstract

BACKGROUND: Psychotic-like experiences (PLEs) are poorly understood phenomenon referring to subclinical psychotic symptoms reported by healthy individuals. Most PLEs are transient, while persistent PLEs might increase the risk of developing psychosis. Examining the contents and persistent rates of PLE could provide insights on the significance of PLEs. METHODS: This on-going study is a 2-year follow-up on the participants who reported PLEs in the Hong Kong Mental Morbidity Survey 2010 (HKMMS), aiming to examine the persistence of self-reported PLEs. The HKMMS was an epidemiological study carried out in 2010 to 2013, targeted at general population aged 16 to 75 years. Psychotic-like experiences were assessed by Psychotic Screening Questionnaire (PSQ), where subjects endorsed ≥1 items in PSQ at baseline (HKMMS) and follow-up were regarded as having persistent PLEs. When a pair of identical or similar PLEs was reported by the same subject at both time points, it is regarded as persistent phenomenon. RESULTS: Data of 62 participants were analysed: 43 (69.4%) were female, aged from 19 to 72 (mean, 44.97; standard deviation [SD], 13.84) years. Overall, 31 (50%) participants reported persistent PLEs with 13 (21%) reported a change of types. At baseline, the total number of PLEs reported was 134 (mean, 2.16; SD, 1.47), where 46 (34.23%) was thought, 72 (53.73%) was perception, and 16 (11.94%) was unusual experience. At follow-up, the total number of PLEs reported was 66 (mean, 1.06; SD, 1.25), where 20 (33.30%) was thought, 36 (54.55%) was perception, and 10 (15.15%) was unusual experiences; in which, 5/20 “thoughts”, 2/36 “perception”, and 2/10 “unusual experiences” were persistent phenomenon. There was no significant difference in the number of baseline PLEs between participants with and without persistent PLEs (U = 462.0, p = 0.76). CONCLUSION: The current preliminary results suggested the highly unstable nature of PLEs in the general population. Further study is needed to examine in detail the nature of PLEs and its significance.