individual possesses at that SNP. PRS approaches are widely used in psychiatric genetics, including substance use and dependence, and can be used to assess whether genetic risk for one disorder or trait is associated with aspects of the same trait, or with a correlated disorder/trait21,22. For instance, one study found that PRS for schizophrenia risk predicted cannabis use in individuals with bipolar disorder23. However, few studies have explored how genetic propensity to cannabis initiation (i.e., cannabis PRS) influences patterns of cannabis use across development.
