Genome-wide significance is generally considered any SNP with a p value less than 5 × 10 −8 ; however, SNPs reaching borderline significance, p < 10 −7 , will also be extracted as borderline significance has been found to be generally replicable [ 17 ].
Limitations at the study level may include a lack of reporting quality control steps, reporting of variants within linkage disequilibrium, small sample size, and a lack of reporting variants that failed to reach genome-wide significance ( p < 5 × 10 −8 ) but may have reached borderline significance levels ( p < 10 −7 ).
Additionally, the GWAS catalog will be manual searched for borderline significant variants associated with current cannabis use, lifetime cannabis use, or CUD to ensure all variants are captured within this review.