Abstract: Over the past 50 years, anecdotal reports linking cannabis sativa (marijuana) and psychosis have been steadily accumulating, giving rise to the notion of “cannabis psychosis.” Despite this historic connection, marijuana often is regarded as a “soft drug” with few harmful effects. However, this benign view is now being revised, along with mounting research demonstrating a clear association between cannabis and psychosis. In this article, I review evidence on marijuana’s impact on the risk of developing psychotic disorders, as well as the potential contributions of “medical” marijuana and other legally available products containing synthetic cannabinoids to psychosis risk.