University of Oulu

Palomäki, J., Therman, S., Kerkelä, M., Järvelin, M.-R., Jones, P., Murray, G. K., Nordström, T., Heinimaa, M., Miettunen, J., Veijola, J., & Riekki, T. (2023). Specific adolescent prodromal symptoms associated with onset of psychosis in the Northern Finland Birth Cohort 1986. Early Intervention in Psychiatry, 17( 7), 692– 701.

Specific adolescent prodromal symptoms associated with onset of psychosis in the Northern Finland Birth Cohort 1986

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Author: Palomäki, Johanna1; Therman, Sebastian2; Kerkelä, Martta1;
Organizations: 1Department of Psychiatry, Research Unit of Clinical Neuroscience, University of Oulu, Oulu, Finland
2Mental Health Unit, Finnish Institute for Health and Welfare, Helsinki, Finland
3Imperial College London, London, UK
4Department of Psychiatry, University of Cambridge, Cambridge, UK
5Northern Finland Birth Cohorts, Arctic Biobank, Infrastructure for Population Studies, Faculty of Medicine, University of Oulu, Oulu, Finland
6Medical Research Center Oulu, Oulu University Hospital and University of Oulu, Oulu, Finland
7Center for Life Course Health Research, University of Oulu, Oulu, Finland
8Department of Psychiatry, University of Turku, Turku, Finland
9Department of Psychiatry, Oulu University Hospital, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.9 MB)
Persistent link:
Language: English
Published: John Wiley & Sons, 2023
Publish Date: 2023-01-24


Background: Several psychological symptoms in adolescence associate with later development of psychosis. However, it is unclear which symptoms specifically predict psychotic disorders rather than psychiatric disorders in general. We conducted a prospective study comparing how specific adolescent psychotic-like symptoms, predicted psychotic and non-psychotic hospital-treated psychiatric disorders in the population-based Northern Finland Birth Cohort 1986 (NFBC1986).

Methods: At age 15–16 years, 6632 members of the NFBC1986 completed the PROD-screen questionnaire. New hospital-treated mental disorders of the NFBC1986 participants were detected between age 17 and 30 years from the Finnish Care Register for Health Care. Multiple covariates were used in the analysis.

Results: During the follow-up, 1.1% of the participants developed a psychotic and 3.2% a non-psychotic psychiatric disorder. Three symptoms were specifically associated with onset of psychosis compared to non-psychotic psychiatric disorders: ‘Difficulty in controlling one’s speech, behaviour or facial expression while communicating’ (adjusted OR 4.00; 95% CI 1.66–9.92), ‘Difficulties in understanding written text or heard speech’ (OR 2.25; 1.12–4.51), and ‘Difficulty or uncertainty in making contact with other people’ (OR 2.20; 1.03–4.67). Of these, the first one remained statistically significant after Bonferroni correction for multiple comparisons.

Conclusions: To our knowledge, this is the first general-population-based prospective study exploring psychiatric symptoms predicting the onset of hospital-treated first-episode psychosis in comparison to non-psychotic disorders. We found three symptoms related with difficulties in social interaction which predicted onset of psychosis. This is a novel finding and should be replicated.

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Series: Early intervention in psychiatry
ISSN: 1751-7885
ISSN-E: 1751-7893
ISSN-L: 1751-7885
Volume: 17
Issue: 7
Pages: 692 - 701
DOI: 10.1111/eip.13363
Type of Publication: A1 Journal article – refereed
Field of Science: 3112 Neurosciences
3124 Neurology and psychiatry
Dataset Reference: NFBC data is available from the University of Oulu, Infrastructure for Population Studies. Permission to use the data can be applied for research purposes via electronic material request portal. In the use of data, we follow the EU general data protection regulation (679/2016) and Finnish Data Protection Act. The use of personal data is based on cohort participant's written informed consent at his/her latest follow-up study, which may cause limitations to its use. Please, contact NFBC project center (NFBCprojectcenter(at) and visit the cohort website for more information.
Copyright information: © 2022 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.