CDH13 has been implicated in drug-abuse related phenotypes by multiple studies from the same group that aggregate evidence at the gene level; specifically, methamphetamine dependence [52], alcohol dependence [53], [54], nicotine dependence [55], [56], successful smoking cessation [57], polysubstance dependence [58], addiction vulnerability [59], and comorbid depression and alcohol dependence [60]. This evidence concerns the gene CDH13 and nicotine dependence.