disorder has not been determined. Although GWASs of cannabis use have been studied in the context of a variety of psychiatric and psychosocial correlates, it is expected that some divergent associations will be seen when looking at cannabis use disorder. Previous studies have drawn causal links between cannabis exposure and brain volume, but the relationship between genetic liability to cannabis use disorder and brain volume in individuals naive to cannabis has not yet been studied.Added value of this studyOur study is the current largest GWAS of cannabis use disorder and the first to include a transancestral component. We found a novel risk locus on chromosome 7. The lead risk variant at this locus is an eQTL for FOXP2—a gene previously implicated in risk-taking behaviours. Contrasting cannabis use and cannabis use disorder, we found that increased liability for cannabis use disorder is genetically correlated with low educational attainment, early age at first birth, and high body-mass index, traits that show opposite directions of association with lifetime cannabis ever-use. We also found that genetic liability for cannabis use disorder is associated with increased risk of mental health problems, infectious diseases, and respiratory illnesses in a large independent sample. Finally, we found a
