Evidence map›Paper›PMID 41997704›Full record

ArticleBMJ open2026

Preschool care early in life and mental health in adolescence in Sweden: a cohort study.

Krisztina D László, Hua Chen, Filip Andersson, Maria Rosaria Galanti

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Article in BMJ open, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors.

Krisztina D LászlóDepartment of Global Public Health, Karolinska Institutet, Stockholm, Sweden krisztina.laszlo@ki.se.ORCID http://orcid.org/0000-0002-4695-477X
Hua ChenDepartment of Global Public Health, Karolinska Institutet, Stockholm, Sweden.ORCID http://orcid.org/0000-0002-4884-3360
Filip AnderssonDepartment of Global Public Health, Karolinska Institutet, Stockholm, Sweden.
Maria Rosaria GalantiDepartment of Global Public Health, Karolinska Institutet, Stockholm, Sweden.ORCID http://orcid.org/0000-0002-7805-280X

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectiveDespite the high rates of early enrolment in preschool and of poor mental health in adolescence in Sweden, knowledge regarding their association in Sweden is lacking. We investigated whether age at starting preschool and weekly hours spent at preschool in different ages are associated with mental ill-health in Swedish adolescents.

designA cohort study based on data from KUPOL (Swedish acronym for 'Knowledge about Adolescents Mental Health and Learning'). SETTING AND

participantsWe used data from KUPOL, a longitudinal study conducted during 2013-2018, involving Swedish adolescents born 2000-2001. We included in the current analyses adolescents with available information on the exposures and the outcomes of interest (n=2261). OUTCOME MEASURES: Study participants and their parents completed questionnaires concerning the child's age (in months) at start of preschool, the average weekly hours in preschool in different ages, the adolescent's mental health, lifestyle, school-related, psychosocial and parental sociodemographic factors. We analysed the association between preschool-related factors and mental health using logistic regression.

resultsChildren enrolled in preschool at the age of 12-15 months had increased odds of high overall and externalising problems score on the Strengths and Difficulties Questionnaire relative to those enrolled at 20 months or later. The corresponding ORs (95% CIs) were 1.39 (95% CI 1.02 to 1.90) and 1.52 (95% CI 1.08 to 2.16), while the corresponding population attributable fractions were 8% and 9%, respectively. There were no associations between age at start of preschool and internalising problems, nor between the average weekly hours at preschool and mental health.

conclusionWe found weak and inconsistent evidence for a link between early preschool attendance and mental health in adolescence; population attributable fractions suggest limited public health implications for the studied associations. The results should be interpreted in light of the methodological constraints of observational studies, the multitude of our comparisons and the sample selection.

Indexed as

Child CareMental DisordersMental HealthAdolescentAge FactorsChild, PreschoolFemaleHumansInfantLongitudinal StudiesMaleSurveys and QuestionnairesSwedenAdolescentChildMENTAL HEALTHSchools

Identifiers

PMID41997704
PMCPMC13110637

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.