In summary, our GWAS of lifetime cannabis use, which is the largest to date, revealed significant SNP and gene associations in 16 regions, 14 of which have not been previously implicated in cannabis use. The most promising candidates for future functional studies are CADM2, NCAM1, and multiple genes located at 16p11.2. Our findings further indicated a causal influence of schizophrenia on cannabis use and substantial genetic overlap between cannabis use and use of other substances, mental health traits, and personality traits, including smoking and alcohol use, schizophrenia, ADHD, and risk-taking.
