Association between participation to the Northern Finland Birth Cohort 1986 and mental disorders and suicidal behaviour

Kerkelä, Martta; Gissler, Mika; Veijola, Juha

doi:2022.0.0.e2022005

Original article

Epidemiology and Health 2022;e2022005.
DOI: https://doi.org/10.4178/epih.e2022005 [Accepted] Published online Jan 3, 2022.

Association between participation to the Northern Finland Birth Cohort 1986 and mental disorders and suicidal behaviour

Martta Kerkelä¹

, Mika Gissler^2,3,4,5

, Juha Veijola^1,6,7

¹Research Unit of Clinical Neuroscience, University of Oulu, Oulu, Finland
²Finnish Institute for Health and Welfare, Helsinki , Finland
³University of Turku, Research Centre for Child Psychiatry, Turku, Finland
⁴Academic Primary Health Care Centre, Region Stockholm, Sweden
⁵Karolinska Institute, Department of Molecular Medicine and Surgery, Stockholm, Sweden
⁶Department of Psychiatry University Hospital of Oulu, Oulu, Finland
⁷Medical Research Center, University Hospital and University of Oulu, Oulu, Finland

Correspondence Martta Kerkelä ,Email: martta.kerkela@oulu.fi

Received: Jun 15, 2021 Accepted after revision: Dec 11, 2021

Abstract

Objectives:
In the prospective follow-up studies participants are normally contacted during the follow-up. Even though the idea is not to intervene, the studies conducted during follow-up may affect the target population. Our hypotheses were that the participation to prospective Northern Finland Birth Cohort 1986 study (NFBC 1986) increases the use of mental health services and reduces the suicidal behaviour due to participation in follow-up study.
Method:
The study cohort NFBC 1986 covers the people born with expected date of birth between July 1985 and June 1986 in northern Finland (N=9,396). The participants of the NFBC 1986 have been followed since antenatal time with follow-ups including clinical examinations. The comparison cohort comprises of people born in the same area in 1987 (N=8,959), who have not been contacted. Register data of psychiatric treatment, suicide attempts and suicides were available. Crude risk ratios (RR) and adjusted (with marital status and education) Mantel-Haenszel Risk Ratios (RR^MH) were reported.
Results:
No significant differences between NFBC 1986 and comparison cohorts in any mental disorders were detected. In crude risk ratio analysis of female, the decreased risk for the suicide attempts was found (RR: 0.67 (95% CI: 0.49-0.92), p=0.011).
Conclusions:
Results did not support our first hypothesis of increased use of mental health services in the NFBC 1986. On the other hand, our second hypothesis gained some support as female participants of the NFBC 1986 had decreased risk for suicide attempts, although it was not due to higher number of participants receiving psychiatric treatment.

Keywords: Psychiatry; Suicide; Follow-up study