This thesis aimed to examine cannabis use patterns by quantity in the United States, identify key characteristics of the heaviest cannabis users, and conduct an initial assessment of whether the prevention paradox may hold for cannabis use in the United States. Using data from the National Epidemiologic Survey on Alcohol and Related Conditions – III, findings suggest that a small portion of the cannabis-using population consumes the majority of the yearly cannabis supply in the United States. Characteristics that affect the odds of being a heavy cannabis user include age, sex, personal income, education level, age of initiation, and the presence of a cannabis use or nicotine use disorder. A larger absolute number of cases experience cannabis-related harms in the low-to-moderate-using group compared to the heaviest-using group. However, a higher percentage of heavy cannabis users experience cannabis-related harms. Therefore, a dual-pronged approach of both targeted and population-based strategies may be appropriate.