DPH Releases Mandated State Study of Marijuana Use

BOSTON — A new, statewide study of marijuana use among Massachusetts residents found that about 21% of adults had used marijuana in the past 30 days, and the proportion of marijuana use was highest among 18- to 25-year-olds.

The study, conducted by the Massachusetts Department of Public Health (DPH), was mandated by the Legislature as part of its revisions to the 2016 adult-use marijuana law. The purpose of the study was to investigate the patterns of use, methods of consumption, and general perceptions of marijuana; incidents of impaired driving and hospitalization related to marijuana use; and the economic and fiscal impacts for state and local governments.

“The study establishes a baseline measurement of how marijuana is used and how that affects public health, public safety, and potential revenue in the state before adult-use marijuana becomes widely available,’’ said Marc Nascarella, the study’s principal investigator.

Among the study’s other highlights, smoking is the most common method of marijuana consumption, although more than 40% of marijuana users report using multiple methods of use. More than half of adults perceive marijuana to have slight or no risks and use marijuana for non-medical purposes.

A survey of patients who use marijuana products for medical use suggests that the average person uses marijuana 24 days a month, with the majority using marijuana products for at least 21 out of the past 30 days.

Among respondents that use marijuana, 34.3% reported driving under the influence. Overall, 7.2% of the adult population drove under the influence of marijuana in the past 30 days, and 11.3% of adults rode with a marijuana-using driver in the past 30 days. This is similar to estimates from a survey of medical marijuana patients that found approximately 10% of respondents drove under the influence in the past 30 days.

The number of marijuana-related calls to the Regional Poison Control Center in Massachusetts has been increasing over time. The calls include incidents of unintentional exposures among children, with the majority of calls related to 10- to 19-year-old individuals, and/or exposure to dried marijuana flower. The proportion of calls increased after medical marijuana was available in the Commonwealth. 

Economic projections suggest that marijuana will increase Massachusetts state revenue by about $215.8 million in the first two years of retail sales. The increase will largely come from sales and excise taxes collected on retail purchases. Based on experiences from states with existing legalized adult use, sales-tax revenue is expected to be higher in the second year ($154.2 million), as compared to the first year ($61.6 million). 

The study began in early 2017 and was conducted by DPH, in consultation with the Executive Office of Health and Human Services, the Executive Office for Administration and Finance, and the Executive Office of Public Safety and Security. In addition to state-agency expertise, DPH partnered with the UMass Donahue Institute/UMass Amherst School of Public Health and Health Sciences, Mathematica Policy Research Inc., and JSI Research and Training Inc. to assist with the execution of the study.