Do subthreshold psychotic experiences predict clinical outcomes in unselected non-help-seeking population-based samples? A systematic review and meta-analysis, enriched with new results

• Main Authors: Kaymaz, N., Drukker, M., Lieb, Roselind, Wittchen, Hans-Ulrich, Werbeloff, N., Weiser, M., Lataster, T., van Os, J.
• Other Authors: Technische Universität Dresden, Fakultät Mathematik und Naturwissenschaften
• Format: Article
• Language: English
• Published: Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden 2013
• Subjects: Wahnvorstellungen; Halluzinationen; Meta-Analyse; Prävention; psychotische Störungen; Risiko; Delusions; hallucinations; meta-analysis; prevention; psychotic disorders; risk; ddc:150; rvk:CU 3000
• Online Access: http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-117329; http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-117329; http://www.qucosa.de/fileadmin/data/qucosa/documents/11732/1415.pdf

Background The base rate of transition from subthreshold psychotic experiences (the exposure) to clinical psychotic disorder (the outcome) in unselected, representative and non-help-seeking population-based samples is unknown. Method A systematic review and meta-analysis was conducted of representative, longitudinal population-based cohorts with baseline assessment of subthreshold psychotic experiences and follow-up assessment of psychotic and non-psychotic clinical outcomes. Results Six cohorts were identified with a 3–24-year follow-up of baseline subthreshold self-reported psychotic experiences. The yearly risk of conversion to a clinical psychotic outcome in exposed individuals (0.56%) was 3.5 times higher than for individuals without psychotic experiences (0.16%) and there was meta-analytic evidence of dose–response with severity/persistence of psychotic experiences. Individual studies also suggest a role for motivational impairment and social dysfunction. The evidence for conversion to non-psychotic outcome was weaker, although findings were similar in direction. Conclusions Subthreshold self-reported psychotic experiences in epidemiological non-help-seeking samples index psychometric risk for psychotic disorder, with strong modifier effects of severity/persistence. These data can serve as the population reference for selected and variable samples of help-seeking individuals at ultra-high risk, for whom much higher transition rates have been indicated.