This study aims to evaluate a new driving simulator, called ADRIS 2.1, developed for adolescents aged 13-18 years with Attention Deficit Hyperactivity Disorder (ADHD). ADHD is a common neurodevelopmental disorder that can affect attention, self-control, and decision-making. These challenges may impact daily activities, including driving.

The ADRIS simulator allows participants to "drive" in a virtual environment while their performance is monitored. The system measures driving errors (such as not stopping at red lights), head and body movements, and heart rate, helping researchers understand how ADHD may affect driving-related behavior.

Participants in the study will include both adolescents with ADHD and typically developing adolescents. All participants will complete standardized cognitive and behavioral assessments and take part in at least one driving simulation session. Adolescents with ADHD will return for follow-up visits and a subgroup will participate in a 6-week training program using the simulator.

The main goal of the study is to measure differences in driving performance and attention between adolescents with and without ADHD. The study will also explore whether the simulator can detect improvements over time and in response to clinical treatment or simulator-based training.

The results may help inform future clinical evaluations and support tools for adolescents with ADHD, with the potential to improve safety and quality of life.

INTRODUCTION

Attention Deficit Hyperactivity Disorder (ADHD) is a common neurodevelopmental condition characterized by persistent symptoms of inattention, hyperactivity, and impulsivity. These impairments can significantly impact an adolescent's daily functioning, academic achievement, and social development. Among the various life skills affected by ADHD, driving represents a particularly complex and high-risk activity, requiring the integration of cognitive, attentional, and executive functions. Adolescents with ADHD are disproportionately involved in traffic violations and accidents compared to their neurotypical peers, largely due to reduced inhibitory control, poor hazard perception, and increased distractibility.

Traditional clinical assessments often fail to capture how cognitive and behavioral deficits associated with ADHD manifest in ecologically valid tasks such as driving. Existing tools are limited in their ability to provide objective, task-based evaluations of attention and self-regulation under realistic conditions. Moreover, there is a scarcity of tailored assessment instruments for the adolescent ADHD population, especially those that can be integrated into clinical pathways for diagnosis, monitoring, and intervention.

RATIONALE OF THE STUDY

This study addresses the need for innovative tools to assess and monitor cognitive-behavioral functioning in adolescents with ADHD. We introduce ADRIS 2.1, a customizable driving simulation platform specifically designed for this population. ADRIS integrates real-time measurement of driving behavior, physiological response (heart rate), and body movements, offering a safe and standardized environment for testing attention, impulse control, and decision-making in dynamic scenarios.

Unlike conventional evaluations, ADRIS allows for adaptive testing: the simulation parameters (e.g., scenario duration, obstacle type, voice prompts) can be modified to match the cognitive load and attentional profile of the user. This flexibility enables clinicians to replicate real-world challenges while collecting objective, quantifiable data related to attentional lapses, impulsive actions, and physiological stress responses.

The study aims to validate ADRIS as a clinical support tool by comparing the driving performance of adolescents with and without ADHD, assessing the correlation between simulator outcomes and standardized neuropsychological tests, and analyzing changes in driving behavior following usual clinical interventions (pharmacological and non-pharmacological). In addition, the study explores whether repeated training with ADRIS may contribute to improvements in attention regulation and driving strategies.

DEVICE DESCRIPTION

ADRIS 2.1 is a driving simulator composed of the following components:

• Steering wheel and pedals connected to a PlayStation console
• 32" monitor displaying high-resolution driving environments
• Integrated camera system for tracking head and torso movements
• Heart rate monitor positioned on the left pectoral area

The system is supported by software developed on the Unreal Engine platform, designed to:

• Generate realistic urban and suburban driving scenarios
• Provide interactive navigation with auditory guidance
• Present neutral, congruent, and incongruent visual stimuli to test attentional control
• Acquire and analyze metrics such as lane crossing, reaction time, speed variability, and physiological responses

STUDY OBJECTIVES

Primary Objective:

Compare the number of traffic violations (e.g., ignored stop signs, red lights, speed limits, collisions) between adolescents with ADHD and neurotypical controls as an index of impulsivity and attentional regulation.

Secondary Objectives:

• Analyze body movement and heart rate data to assess physiological and behavioral differences during driving tasks
• Correlate simulator performance with standardized neuropsychological test results
• Monitor intra-individual changes over time (baseline vs. follow-up) to assess the impact of clinical treatments
• Evaluate the effect of repeated ADRIS-based training on driving behavior and attentional control in a randomized subgroup

PARTICIPANTS

A total of 120 participants (60 ADHD, 60 controls) aged 13 to 18 years will be enrolled across two centers: IRCCS Istituto Giannina Gaslini (Genoa) and IRCCS Fondazione Stella Maris (Pisa). Recruitment will include both clinic-referred individuals and participants engaged via ADHD family associations and educational institutions.

STUDY PROCEDURES

T0 (All participants):

ADHD group: full neuropsychological battery, standardized questionnaires (e.g., WISC/WAIS, NEPSY-II, CBCL, CONNERS 3), first ADRIS session (6 driving scenarios)

Control group: short screening questionnaire, ADRIS simulator session (same protocol)

T1 (ADHD only):

At 3 months: repeat ADRIS session and neuropsychological assessments (excluding cognitive battery)

T2 Sub-study (ADHD only):

30 ADHD participants will be randomized into two age- and sex-matched groups:

Training group: 12 simulator training sessions over 6 weeks

Control group: no training

Both subgroups will undergo pre- and post-training ADRIS testing and neuropsychological evaluation (excluding cognitive battery)

STIMULI AND TASK DESIGN

During simulator sessions, participants will encounter:

• Neutral stimuli: non-threatening static obstacles (e.g., trash bins)
• Congruent stimuli: dynamic, context-appropriate obstacles (e.g., pedestrian crossing)
• Incongruent stimuli: misleading cues followed by sudden hazards (e.g., decoy pedestrian followed by car)

These scenarios test attentional capture, inhibition, and adaptive decision-making. Each session lasts ~30 minutes.

Statistical Analysis

Sample size was calculated using G*Power for independent-sample t-tests, assuming a medium effect size (d = 0.5), a power of 95%, and an alpha level of 0.05. This yielded a requirement of 54 participants per group. To account for an estimated 10% dropout rate, the total sample size was increased to 120 participants (60 per group).

The primary outcome (number of traffic violations) will be analyzed using parametric or non-parametric tests, depending on the distribution and homogeneity of variance of the data.

Secondary outcomes will be analyzed as follows:

• Correlation analyses (Pearson or Spearman) to assess relationships between clinical and instrumental measures.
• Repeated measures ANOVA or Friedman tests for within-subject comparisons over time.
• Mixed-model ANOVA for analyzing training effects, with group as a between-subject factor and time as a within-subject factor.

Both statistical significance (p-values) and clinical relevance will be evaluated to interpret the results meaningfully.

ETHICAL CONSIDERATIONS

The study will follow the Declaration of Helsinki and GCP standards. Ethics approval has been obtained from the National Pediatric Ethics Committee. Participants will provide informed consent/assent. Risks are minimal and limited to possible simulator-related discomfort (e.g., motion sickness). Mitigation protocols and trained staff will ensure participants' safety.

POTENTIAL BENEFITS

While no direct clinical benefits are guaranteed, participants may gain greater awareness of their attentional functioning. The study will contribute to developing novel clinical tools for ADHD assessment and training, potentially improving treatment personalization and long-term outcomes in adolescents.

Inclusion Criteria for ADHD subjects:

• Age range 13-18 years (up to the age of nineteen)
• Diagnosis of ADHD (hyperactive, inattentive and combined subtype)
• Consent to participate in the study by the participant or, in the case of a minor, by their parent(s)/guardian(s).

Inclusion Criteria for Control Group subjects:

• Age- and sex-matched neurotypical adolescents
• No diagnosis of ADHD or other neurodevelopmental disorders
• Informed consent obtained from the participant if of legal age or from the legal guardian and assent from the minor

Exclusion Criteria:

• Visual deficits not corrected/correctable with the normal use of lenses.
• Motor deficits clinically detected and/or previously diagnosed and that could compromise the use of the simulator (e.g. neurological diseases, psychiatric diseases, etc.).
• Categorical diagnoses according to DSM-5 criteria such as Psychosis, Mood Disorders, Autism Spectrum Disorders, Intellectual Disabilities, Borderline Intellectual Functioning, Anxiety Disorders.
• Patients with other conditions that could affect driving ability.
• Denial / withddrawal of consent to the protocol