We have demonstrated genetic heterogeneity among individuals with ADHD depending on age at first diagnosis. The genetic architecture of ADHD diagnosed in adults overlaps to a greater extent with the genetics of depression than ADHD diagnosed in children whereas the genetic architecture of childhood ADHD overlaps with the genetics of autism to a greater extent than ADHD diagnosed as adult (Rajagopal et al. Nature Genetics 2022).
We identified the first genome-wide significant loci for DBDs in the context of ADHD ADHD is highly comorbid with disruptive behaviour disorders (DBDs) and we identified the first genome-wide significant loci for DBDs in the context of ADHD and a found a high genetic correlation of ADHD comorbid with DBDs with aggression compared to having ADHD without DBDs (Demontis et al. Nature Communications 2021).
We were the first to report increased burden in ADHD cases of rare deleterious variants in evolutionary constrained genes Based on the to-date largest exome-sequencing data of ADHD, we were the first to report increased burden in ADHD cases of rare deleterious variants in evolutionary constrained genes (Satterstrom et al. 2019).
We have previously identified and replicated the first genome-wide significant risk locus for cannabis use disorder. The risk variants affect CHRNA2 expression, a gene encoding the alpha-2 subunit of the nicotine receptor (Demontis et al. Nature Neuroscience ).
We followed up with a large GWAS meta-analysis of cannabis use disorder In collaboration with the Psychiatric Genomics Consortium and deCODE genetics we followed up with a large GWAS meta-analysis of cannabis use disorder, which revealed an additional risk locus implicating FOXP2 in cannabis use disorder (Johnson, Demontis, Thorgeirsson et al. 2020, Lancet Psychiatry).