There appears to be a significant genetic overlap between cannabis use and major depression among Mexican Americans, a pleiotropy that appears to be localized to a region on chromosome 11q23 that has been linked previously to these phenotypes, a recent study found. Researchers examined participants from the Genetics of Brain Structure and Function Study (GOBS), which consisted of 1,284 Mexican Americans from 75 large multi-generation families and an additional 57 genetically unrelated spouses. They found:

• Both cannabis use and major depression are heritable traits, and there is significant genetic correlation between the 2.
• Genome-wide linkage scans identify a significant univariate linkage peak for major depression on chromosome 22, with a suggestive peak for cannabis use on chromosome 21.
• A significant pleiotropic linkage peak influencing both cannabis use and major depression was identified on chromosome 11 using a bivariate model.