Skip to content

A population-based cohort study examining the incidence and impact of psychotic experiences from childhood to adulthood, and prediction of psychotic disorder.

Research output: Contribution to journalArticle

Original languageEnglish
Number of pages10
JournalAmerican Journal of Psychiatry
Early online date7 Jan 2020
DateAccepted/In press - 11 Oct 2019
DateE-pub ahead of print (current) - 7 Jan 2020


Objective: To investigate the incidence, course and outcome of psychotic experiences from childhood through early adulthood in the general population, and prediction of psychotic disorder.

Methods: A population-based cohort study using the semi-structured Psychosis-like Symptoms interview of psychotic experiences at ages 12, 18, and 24 (N=7900 with any data). Incidence rates were estimated using flexible parametric modelling, and positive predictive values (PPV), sensitivity, specificity, and area under the curve estimated for prediction.

Results: The incidence rate of psychotic experiences increased between ages 13-24 years, peaking during late adolescence. Of 3866 interviewed at age 24, 313 (8.1%, 95%CI 7.2%, 9.0%) had a definite psychotic experience since age 12. 109 individuals (2.8%) met criteria for a psychotic disorder up to age 24, of whom 70% had sought professional help. Prediction of current psychotic disorder at age 24 (N=47, 1.2%) by both self-report and interviewer-rated measures of psychotic experiences at age 18 (PPVs 2.9% and 10.0% respectively) was improved by incorporating information on frequency and distress (PPVs 13.3% and 20.0% respectively), although sensitivities were low. The PPV of an at-risk mental state at age 18 predicting incident disorder ages 18-24 was 21.1% (95%CI 6.1%-45.6%; sensitivity 14.3%, 95%CI 4.0%-32.7%).

Conclusions: Our study shows a peak in incidence of psychotic experience during late adolescence, and an unmet need for care in young people with psychotic disorders. Because of the low sensitivity, targeting individuals in non-help-seeking samples based only on more severe symptom cut-off thresholds will likely have little impact on population-levels of first-episode psychosis.



  • Full-text PDF (accepted author manuscript)

    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via American Psychiatric Publishing at Please refer to any applicable terms of use of the publisher.

    Accepted author manuscript, 271 KB, PDF document

    Embargo ends: 7/01/21

    Request copy


View research connections

Related faculties, schools or groups