Examining the Relationship between Amount of Cannabis Purchased and Cannabis Use Characteristics

Background and Purpose: The legal and illegal availability of cannabis has greatly increased due to various policy changes that have occurred in the past few decades in the United States. However, relatively little is known regarding the relationship between cannabis purchasing behaviors and outcomes of cannabis use. Therefore, the purpose of this study was to examine what relationship exists between the amount of cannabis last purchased and the likelihood of having met the criteria for a past-year cannabis use disorder.

Methods: Data came from the 2023 National Survey on Drug Use and Health (NSDUH), an annual nation-wide survey. The sample for this study was adults who had used cannabis in the past year (n=14,185). Respondents were asked to estimate the amount (in grams) of loose cannabis that they had last purchased. A categorical variable was created with three levels: less than 3 grams, 3 to 6.9 grams, and 7 or more grams. A binary variable representing past-year cannabis use disorder was created using criteria found in the fifth edition of The Diagnostic and Statistical Manual of Mental Disorders. Additionally, respondents were asked to estimate how many days in the past month they had used cannabis. A binary variable was created from this data to capture daily cannabis use. Two logistic regression models were estimated to examine the relationship between amount of cannabis purchased and past-year cannabis use disorder as well as the relationship between amount of cannabis purchased and daily cannabis use, while accounting for age, sex, race/ethnicity, past-month binge drinking, and income.

Results: Among past-year cannabis users, 35.6% met criteria for a cannabis use disorder and 20% had used cannabis every day. Additionally, 28% had purchased less than 3 grams of loose cannabis, 39% purchased 3 and 6.9 grams, and 33% purchased over 7 grams. The amount of cannabis last purchased was a significant predictor of having a past-year cannabis use disorder, with individuals purchasing 3 – 6.9 grams having around 64% greater likelihood of a past-year CUD than those who purchased less than 3 grams (AOR= 1.64, p < 0.01, CI= 1.31 – 2.04). Additionally, individuals who had purchased 7 or more grams were nearly 3 times as likely to have a CUD than those who purchased less than 3 grams (AOR= 2.86, p < 0.01, CI= 2.26 – 3.60). Similar effects were observed for daily cannabis use, with 3 – 6.9 grams having around 38% increased likelihood of daily use (AOR= 1.38, p < 0.01, CI= 1.06 – 1.80) and 7 or more grams having around 173% increased likelihood of daily cannabis use (AOR= 2.73, p < 0.01, CI= 2.10 – 3.56).

Conclusion and Implications: Results from this study suggest that significant relationships exist between the amount of cannabis purchased and cannabis use disorder. Findings from this study could be used to inform policies and educational interventions related to the amount of cannabis purchased and sold. Additionally, further research is needed in this area to better understand the purchasing behaviors and patterns of individuals who use cannabis.