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What GWAS findings are most significant in ADHD? 

Genome‑wide association studies (GWAS) have shed fresh light on the genetic underpinnings of ADHD. Recent large GWAS meta‑analyses have uncovered many significant loci and single-nucleotide polymorphisms (SNPs) linked to ADHD, helping clarify how common genetic variants contribute to risk. Below are some of the most impactful findings to date, plus what they mean for understanding ADHD’s genetics and future research. 

Key Genetic Associations from ADHD GWAS 

Here are a few of the major discoveries: 

  • A meta‑analysis including around 38,691 ADHD cases and 186,843 controls identified 27 genome‑wide significant risk loci. These loci are enriched in genes expressed in the brain, especially during development, pointing to neurodevelopmental processes in ADHD.  
  • Earlier, GWAS by Demontis et al. (2019) reported 12 independent genome‑wide significant loci associated with ADHD using ~55,000 individuals. 
  • Newer studies combining ADHD symptom measures (quantitative data) with diagnosis (categorical data) increased power and revealed 39 independent loci, including 17 novel ones, plus thousands of significant variants.  
  • SNP‑based heritability (the proportion of ADHD risk explained by common SNPs) is estimated at around 20‑25% in some of these large studies.  

What Makes These Findings Important 

  • Many of the implicated loci are in non‑coding regions, meaning they likely affect gene regulation (e.g. how much, when, and where certain genes are expressed), rather than changing protein structure directly.  
  • Some risk genes emerging include LSM6 and RPS26 (from analyses integrating fetal brain and induced neuronal data) which suggest that early developmental expression is relevant.  
  • There is also evidence that ADHD GWAS variants overlap significantly with those for other psychiatric disorders (high pleiotropy) and with traits related to cognition and educational attainment. This suggests that ADHD shares some genetic architecture with broader neurodevelopmental and psychiatric traits.   

Visit providers like ADHD Certify for personal consultations informed by the latest genetic findings.

For a deeper dive into the science, diagnosis, and full treatment landscape, read our complete guide to Genetic studies and biomarkers.

Victoria Rowe, MSc, author for my patient advice - mypatientadvice.co.uk

Victoria Rowe, MSc

Author

Victoria Rowe is a health psychologist with a Master’s in Health Psychology and a BS in Applied Psychology. She has experience as a school psychologist, conducting behavioural assessments, developing individualized education plans (IEPs), and supporting children’s mental health. Dr. Rowe has contributed to peer-reviewed research on mental health, including studies on anxiety disorders and the impact of COVID-19 on healthcare systems. Skilled in SPSS, Minitab, and academic writing, she is committed to advancing psychological knowledge and promoting well-being through evidence-based practice.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the author's privacy. 

Dr. Rebecca Fernandez, MBBS, author and a reviewer for my patient advice - mypatientadvice.co.uk

Dr. Rebecca Fernandez, MBBS

Reviewer

Dr. Rebecca Fernandez is a UK-trained physician with an MBBS and experience in general surgery, cardiology, internal medicine, gynecology, intensive care, and emergency medicine. She has managed critically ill patients, stabilised acute trauma cases, and provided comprehensive inpatient and outpatient care. In psychiatry, Dr. Fernandez has worked with psychotic, mood, anxiety, and substance use disorders, applying evidence-based approaches such as CBT, ACT, and mindfulness-based therapies. Her skills span patient assessment, treatment planning, and the integration of digital health solutions to support mental well-being.

All qualifications and professional experience stated above are authentic and verified by our editorial team. However, pseudonym and image likeness are used to protect the reviewer's privacy.