ADHD affects around 5% of children and manifests itself as hyperactivity, attention difficulties and motor control and balance problems. The prevalence of ADHD is particularly high in certain populations, affecting up to 25-30% of children born prematurely and around 20% of children with neurological conditions such as epilepsy. This disorder is officially diagnosed from the age of 6, according to current criteria. However, its clinical manifestations appear much earlier, having a significant impact on all aspects of the child's life, particularly in the most severe forms, which are often unrecognised due to a lack of clinical resources, and therefore without appropriate treatment.

The creation of a platform dedicated to children at risk of ADHD will enable specific clinical expertise to be developed, with the aim of proposing early targeted interventions and positively influencing the development of their trajectory. This platform will also aim to develop new diagnostic methods, based on indirect measures of attentional and executive processes, balance and the development of a risk measurement scale. This development is essential, as the assessment tools currently available lack specificity.

In order to demonstrate the reliability of the innovative diagnostic methods proposed, a comparative pilot study between children from the first clinical cohort (N=30) and a group of healthy children of the same age (N=30) will be carried out. This will enable us to study the discrimination of our tools and make any necessary adjustments. This pilot study also includes a longitudinal re-evaluation, at 12 months, of the children in the ADHD cohort, in order to study changes in these biomarkers over time.

ADHD and control patients will be informed of the study at least 1 week before the inclusion visit.

During the inclusion visit, after consent has been obtained from those with parental authority, patients in both groups will be :

• Review of inclusion and non-inclusion criteria
• Neuropsychological assessment: WPPSI-IV; K-CPT
• Self-questionnaires: ADHD-RS preschool version, temperament scale (CBQ)
• Experimental evaluation: Eye movement recording, vestibular examination, postural recording, VVS test Patients in the ADHD group will be reassessed at 12 months using the same procedure as the inclusion visit.

Inclusion Criteria:

• For ADHD subjects:
• Children aged between 3.0 and 5 years and 11 months, with clinical criteria for ADHD, according to DSM 5.
• Children followed in the Child and Adolescent Psychiatry Department of Robert Debré Hospital.
• Children naïve to pharmacological treatment for ADHD

For control subjects:

• Children between 3.0 - 5 years and 11 months
• No known condition or disease affecting development and behavior

Exclusion Criteria:

• For both groups
• Intellectual disability according to DSM 5 +- WPPSI IV < 70
• Refusal of the child or one of his parents or representatives of parental authority.
• Patient under AME or not affiliated to a social security scheme

30 children aged between 3 and 5 years and 11 months, with clinical criteria for ADHD, will be compared with 30 healthy children of the same age.