The overlap in common genetic risk factors for cannabis use disorder with depressive symptoms is in line with recent observations47 and the association of CUD with increased load of ADHD risk variants suggests that the epidemiological observations of high comorbidity of ADHD with CUD48 are influenced by shared genetic risk components. Likewise, the overlap in common genetic risk variants between CUD and schizophrenia (in line with epidemiological observations22,49 and PRS studies50). However we cannot rule out whether the overlap involves variants with pleiotropic effects, or if the overlap in general is caused by heterogeneity among schizophrenia cases due to a subgroup comorbid with CUD, in line with the CUD risk locus identified here.
