Are ADHD GWAS results consistent across populations? 

Yes, there is growing evidence that ADHD GWAS populations show both shared and population‑specific genetic signals. While many genetic associations identified in ADHD GWAS are strong in people of European ancestry, their replication across other ethnic groups has been less consistent. These matters for both scientific understanding and clinical applications; if findings do not generalise, polygenic scores or risk estimates might be less predictive in underrepresented groups. 

What we know from cross‑ethnic studies 

Here are some of the findings and challenges when comparing ADHD GWAS across different populations: 

Shared loci and risk alleles  

Some of the significant loci discovered in European‑based GWAS are also present in non‑European groups. For example, trans‑ethnic meta‑analyses have combined data from European and non‑European cohorts to identify additional ADHD‑associated loci.This suggests there are genetic associations that are broadly relevant across populations. 

Differences in linkage disequilibrium (LD) and allele frequencies  

Even when the same SNPs or regions are implicated, their effect sizes or detectability can vary because of differences in LD structure (how neighbouring SNPs are correlated) and how common alleles are in different ancestral groups. This can lead to weaker replication or missed associations in some populations.  

Underrepresentation of non‑European populations 

 A central problem is that most large ADHD GWAS studies thus far have heavily sampled European ancestry populations. That means statistical power to detect associations in other populations is often lower. It also means that polygenic risk scores built from European data may perform less accurately in people of non‑European ancestry.  

Genetic correlation and replication  

Studies comparing ADHD diagnosis vs symptom measures find high genetic correlations among European cohorts. But cross‑ethnic replication (i.e., finding the same SNPs or effect directions in different ancestry groups) is still limited. More work is needed.  

What this means and what is next 

• Researchers are pushing for more diverse GWAS, including participants from African, Asian, Latin American, and Indigenous backgrounds, to improve generalisability. 

• Tools that adjust for LD differences and population structure are essential. 

• Eventually, better cross‑ethnic consistency will help make genetic risk prediction fairer and more useful globally. 

Visit providers like ADHD Certify for personal consultations informed by diverse genetic research.

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