NCT04574414

Brief Summary

  • Background: Recent studies have linked exposure to airborne particulate matter (PM) to neurodevelopmental outcomes but the findings are mixed and mechanisms are unclear. We aim to determine the impact of PM on the developing brain of schoolchildren in Poland, a European country characterized by very high levels of air pollution. The investigators aim to determine the impact of PM on the developing brain of schoolchildren in Poland, a European country characterized by very high levels of air pollution.
  • Study area: 19 towns in three voivodeships (Lesser Poland, Silesian, Opole) in the southern Poland. To reduce confounding by urbanicity and at the same time, to achieve sufficient contrasts in PM levels without too high logistic costs, towns were selected by size (big and small) and by PM levels (high, medium and low).
  • Design: Case-control study with 800 children recruited over two school years, with two population controls per one ADHD case. Suspected cases will be recruited in specialized facilities and presumably ADHD-free children will be recruited in primary schools.
  • Exposure assessment: Poland-wide PM and other air pollutants' grids will be created for the years 2006 to 2021 using statistical models to incorporate land use data, estimates from transport models, satellite observations and air pollution measurements from Polish monitoring network. Prenatal, early-life, lifelong and concurrent exposures will be calculated.
  • Psychological testing: Every child and their parents will complete a series of psychological tests and interviews that will be conducted during their three visits to the recruitment facility.
  • Neuroimaging: Each participant will undergo a Magnetic Resonance Imaging (MRI) scanning session that will be performed accordingly to the Human Connectome Adolescent Brain Cognitive Development project recommendations. Scanning will be performed on a single scanner in Krakow.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
800

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Oct 2020

Typical duration for all trials

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

September 22, 2020

Completed
9 days until next milestone

Study Start

First participant enrolled

October 1, 2020

Completed
4 days until next milestone

First Posted

Study publicly available on registry

October 5, 2020

Completed
2.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2022

Completed
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2023

Completed
Last Updated

October 5, 2020

Status Verified

September 1, 2020

Enrollment Period

2.2 years

First QC Date

September 22, 2020

Last Update Submit

September 28, 2020

Conditions

Outcome Measures

Primary Outcomes (6)

  • Attention Deficit Hyperactivity Disorder (ADHD)

    ADHD and comorbidities will be assessed by Conners 3 questionnaire

    October 1, 2020 until December 31, 2022

  • Cognitive functioning

    Memory, attention, and executive functions measurement will be assessed by Diagnostic battery for cognitive functions evaluation (PU1)

    October 1, 2020 until December 31, 2022

  • Attention control

    Attention Network Test (ANT) will be used.

    October 1, 2020 until December 31, 2022

  • Sustained and selective attention

    Computer Conners Continuous Performance Task (CPT) will be used.

    October 1, 2020 until December 31, 2022

  • Inhibition control

    Conditioned Approach Response Inhibition Task (CARIT) will be used as part of MRI measurements.

    October 1, 2020 until December 31, 2022

  • Inhibition control

    Go/No Go task will be used as part of MRI measurements.

    October 1, 2020 until December 31, 2022

Secondary Outcomes (5)

  • Full-Scale Intelligence Quotient (IQ)

    October 1, 2020 until December 31, 2022

  • Family functioning

    October 1, 2020 until December 31, 2022

  • Relationships with siblings

    October 1, 2020 until December 31, 2022

  • Behavioural, emotional, and social problems

    October 1, 2020 until December 31, 2022

  • Behavioural problems

    October 1, 2020 until December 31, 2022

Study Arms (2)

Children with Attention Deficit Hyperactivity Disorder

Cases

Diagnostic Test: Psychological testing and MRI imaging

Children without Attention Deficit Hyperactivity Disorder

Population controls

Diagnostic Test: Psychological testing and MRI imaging

Interventions

Every child will have three sessions with psychologists and be diagnosed as having or not having ADHD. Every child will be invited to Krakow to undergo MRI measurements, including resting-state and event-related functional MRI, Diffusion Tensor Imaging (DTI), and T1/T2 structural MRI.

Children with Attention Deficit Hyperactivity DisorderChildren without Attention Deficit Hyperactivity Disorder

Eligibility Criteria

Age10 Years - 13 Years
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17)
Sampling MethodProbability Sample
Study Population

800 children aged 10-13 will be sampled to the NeuroSmog study. Both ADHD cases and population controls will be enrolled, two control per case. Cases will be recruited in specialized facilities and controls will be randomly sampled in randomly selected 30 primary schools across 19 big and small towns in Lesser Poland, Silesian and Opole voivodeships in the southern Poland.

You may qualify if:

  • Attending school in one of the specified towns
  • Age 10-13 years (4th-6th grade)
  • Native Polish speaker
  • Normal or above intelligence
  • Standard educational opportunities
  • Normal or corrected to normal visual and auditory acuity
  • No gross sensory deficit, no gross behavioural problems
  • No history of neurological disease

You may not qualify if:

  • Autism spectrum disorder (ASD)
  • FAS
  • FAE
  • Intellectual disability
  • Metabolic disorders
  • Genetic disorders
  • Epilepsy
  • Cerebral palsy
  • Mood disorders
  • Tourette Syndrome
  • Other illnesses including pharmacotherapy
  • Apgar score \< 8
  • Low birth weight (below 2500 g)
  • Preterm birth (below 35th weeks of gestation)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Institute of Psychology

Krakow, 30-060, Poland

Location

Related Publications (2)

  • Sitnik-Warchulska K, Izydorczyk B, Sawicki A, Markevych I, Szwed M, Lipowska M. A Dyadic Perspective on ADHD: Adolescent-Parent Reports of Behavioural Problems and Family Functioning. Clin Psychol Psychother. 2026 Jan-Feb;33(1):e70230. doi: 10.1002/cpp.70230.

  • Compa M, Walczak B, Baumbach C, Kolodziejczyk J, Mysak Y, Lipowska M, Izydorczyk B, Sitnik-Warchulska K, Markevych I, Szwed M. Association of Socioeconomic Status With IQ and Attention in School Children in Poland, a Country With Relatively Low Socioeconomic Differences. Dev Psychobiol. 2025 Jul;67(4):e70058. doi: 10.1002/dev.70058.

MeSH Terms

Conditions

Attention Deficit Disorder with HyperactivitySocial Adjustment

Condition Hierarchy (Ancestors)

Attention Deficit and Disruptive Behavior DisordersNeurodevelopmental DisordersMental DisordersSocial BehaviorBehavior

Central Study Contacts

Marcin Szwed, Dr. hab.

CONTACT

Iana Markevych, PhD

CONTACT

Study Design

Study Type
observational
Observational Model
CASE CONTROL
Time Perspective
RETROSPECTIVE
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Leader of the NeuroSmog consortium

Study Record Dates

First Submitted

September 22, 2020

First Posted

October 5, 2020

Study Start

October 1, 2020

Primary Completion

December 31, 2022

Study Completion

December 31, 2023

Last Updated

October 5, 2020

Record last verified: 2020-09

Locations