The Link between ADHD and Childhood Aggression

Julie Girard-Lapointe

Impact

  • The findings reinforced the effectiveness of SNAP (Stop Now and Plan in reducing impulsivity and aggression in children with ADHD symptoms.

  • This project highlighted the need for psychosocial interventions as a powerful tool in improving impulsivity control for children with ADHD-like traits, particularly in at-risk girls who may be more vulnerable to behavioural challenges.

  • Ontario

  • Fellowship

  • University of Montreal

  • Child Development Institute

  • Mitacs, Knowledge Institute on Child and Youth Mental Health and Addictions (KI)

  • 2021-2022

  • Child and Youth Mental Health

  • ADHD and aggression in children

About the Project

This study, conducted in partnership with the Child Development Institute, assessed the effectiveness of the SNAP (Stop Now and Plan) program, a behavioral intervention designed for children aged 6-12 and their parents. The research specifically examined how SNAP impacted children with high ADHD symptoms compared to those with lower symptom levels. Given that girls with ADHD are at higher risk for additional behavioral challenges, the project also explored gender-based differences in intervention outcomes.

Methodology

The study analyzed secondary data from a larger SNAP research project. It focused on high-risk children (ages 6-12) with aggression problems. This research examined ADHD symptoms in attention and hyperactivity, aggression, and rule-breaking tendencies pre and post SNAP interventions.

Behavioral changes before and after SNAP were compared based on:

  •  Boys vs. girls

  • Children with high ADHD symptoms vs. lower symptoms

  • Boys with high ADHD symptoms vs. girls with high ADHD symptoms

  • Boys with lower ADHD symptoms vs. girls with lower ADHD symptoms

Findings

Key findings after SNAP intervention:  

  • Inattention/Hyperactivity: Children with high ADHD symptoms showed a greater reduction in hyperactivity and inattention (reported by parents) compared to those with lower symptoms.

  • Aggression: The greatest reduction in aggression, observed by parents, was in boys and girls with lower ADHD symptom levels. More girls than boys exhibited both severe ADHD symptoms and aggression problems, supporting the idea that girls with ADHD were at greater risk for co-occurring behavioral issues.

  • Rule Breaking Tendencies: Boys with high ADHD symptoms and girls with lower ADHD symptoms showed the most significant reductions in delinquent behavior.

These findings underscored the critical need to focus on at-risk girls, given the presence of multiple externalizing behaviors.  

The research demonstrated that psychosocial interventions from the SNAP program could significantly improve impulsivity control, aggression, and delinquency in children with ADHD-like traits.

Project Outreach

This project was part of a broader SNAP initiative, designed for implementation in 310 communities across Canada and sparked interest from local resources through presentations of findings. Future research could explore the role of parental engagement and the impact of change through the SNAP program on children’s outcomes. Future research projects will be conducted increasing the scaling and impact of these findings

Resources Created

  • Presentation at the Annual Conference of the Canadian ADHD Resource Alliance (CADDRA), in Montreal, QC (September 2023).

  • Trainee Research Award on behalf of this project.

  • Systematic reviews of the literature of studies on the SNAP program.

  • Dissemination of the findings currently under review for publication in a scientific journal.

  • Website and mobile application: https://childdevelop.ca/snap/

  • The researcher’s contribution helped the project to create numerous other resources (click HERE to read about Dr. Leena K. Augimeri and Ms. Margaret Walsh  project).