A recent study conducted by a researcher at Carnegie Mellon University examined cannabis use in the United States from 1979 to 2022. The study discovered that an increasing number of cannabis users are reporting daily or near-daily use, and their numbers now surpass those of daily and near-daily alcohol drinkers. The study also concludes that long-term trends in cannabis use align with corresponding changes in policy during the same period.
ily and near-daily drinkers of alcohol. The research suggests that the long-term patterns in cannabis use are in line with the changes in policy during the same period. The findings are published in Addiction.
“The data is based on self-reported surveys, but the significant changes in rates of self-reported cannabis use, especially daily or near-daily use, indicate that there have been considerable changes in actual use,” explained Jonathan P. Caulkins, a professor at Carnegie Mellon’s Heinz College who led the study. “It is noteworthy that frequent cannabis use is now more frequently reported.The study compared long-term trends for the entire United States, rather than specific states, and focused on the number of days cannabis was used rather than just the prevalence of use. The data was collected from the U.S. National Survey on Drug Use and Health, involving over 1.6 million participants across 27 surveys. The study did not attempt to determine causal effects, but did compare cannabis use to alcohol consumption.The study analyzed marijuana use from 1979 to 2022, focusing on significant policy changes in 1979, 1992, 2008, and 2022. The findings show a decrease in reported cannabis use in 1992, followed by partial increases until 2008 and substantial growth afterward. The data reflects the end of liberal policies in 1979, the conservative Reagan-Bush-era policies in 1992, the non-interference with state-level legalizations in 2008, and the most recent data available in 2022.Between 2008 and 2022, the rate of reporting past-year use per person increased by 120%, and the reported days of use per person increased by 218%. In absolute terms, there was a rise from 2.3 billion to 8.1 billion days per year.
From 1992 to 2022, the rate of reporting daily or near-daily use per person increased by 15-fold. In 1992, the survey recorded 10 times as many daily or near-daily alcohol users as cannabis users (8.9 million versus 0.9 million). However, in 2022, for the first time, the survey recorded more daily and near-daily users of cannabis than of alcohol (17.7 million versus 14.7 million).
- Although more people drink alcohol than use cannabis, frequent drinking is less common. In 2022, the average drinker reported drinking 4-5 days in the previous month, while cannabis users reported using it 15-16 days in the previous month. In 2022, those who used cannabis in the previous month were almost four times more likely to report daily or near-daily use (42% versus 11%) and 7.4 times more likely to report daily use (28% versus 3.8%).
“These trends reflect changes in policy, with declines during periods of stricter regulations and increases during periods of policy liberalization,” explains Caulkins. He notes that this does not imply that policy decisions are the sole cause of these trends.The use of cannabis has changed significantly, which may be a reflection of shifts in cultural and attitudes. Regardless of the causality, cannabis use has clearly increased since legalization. However, the study has limitations such as relying on self-reported data from general population surveys, lacking validation from biological samples, and excluding certain subpopulations with different usage rates.
