Editorial: Nonmedical (“recreational”) cannabis use and cannabis laws have changed over the past two decades in the United States (1) and the rest of the world (2). Increasing use, especially among the young, coupled with the increasing potency of cannabis (higher delta-9-tetrahydrocannabinol [THC] content) during this period (3), has raised concerns about the long-term health impact of cannabis exposure, especially among adolescents and young adults. There is recognition of an association between cannabis use and psychosis, but whether the relationship is causal continues to be debated. One rebuttal raised in this debate is that if cannabis caused psychosis, then the increases in the rates of cannabis use should be accompanied by a parallel increase in the rates of psychosis.