The La Guardia Committee Report, published in 1944 as “The Marihuana Problem in the City of New York,” was a study by the New York Academy of Medicine for a committee appointed in 1939 by New York Mayor Fiorello La Guardia, and it found that marijuana did not cause addiction, violent crime or a move to harder drugs. It was the most thorough American study of cannabis in its era and directly contradicted the claims federal narcotics chief Harry Anslinger had used to win the 1937 Marihuana Tax Act. Anslinger attacked it, and federal policy ignored it for decades.
The Weed Street Journal summarized the report’s clinical tests in an earlier post. This rewrite covers who ran the study, how they did it, what they concluded, how Washington reacted, and why the report is still cited more than 80 years later. For the law it challenged, see our article on the Marihuana Tax Act of 1937.
What Happened
La Guardia, a critic of the 1937 federal law, asked the New York Academy of Medicine to examine the “marihuana problem” in the city. The committee he appointed in 1939 spent more than five years on the work, according to the history of the committee, and published its findings in 1944. The report had two halves: a sociological study of how marijuana was bought and used on the city’s streets, and a clinical study of its effects on people.
For the sociological study, six members of the New York Police Department worked as investigators, visiting the places where marijuana was sold and smoked. They estimated that as many as 500 peddlers and 500 “tea pads,” rooms or apartments where people gathered to smoke, operated in the city, mostly in Harlem and around Broadway between 42nd and 59th Streets. The authors stressed the figure was an estimate from observation and conversation, not a census, as the historian writing for Points, the drug history blog, has described.
The clinical study tested 77 people: 72 subjects (65 men and 7 women) held under the supervision of the city’s Department of Correction, plus a control group of five. All 72 volunteered, and 48 had used marijuana before. Researchers gave them measured doses and recorded physical, mental and behavioral effects. Subjects reported relaxation, lowered inhibition and self-confidence, and some reported anxiety. None became violent, and none showed lasting personality change.
What the Report Concluded
The report ended with 13 conclusions. Among them:
- Marijuana use was widespread in parts of Manhattan, but the problem was not as acute as reported elsewhere.
- Smoking marijuana did not lead to addiction in the medical sense.
- It did not lead to morphine, heroin or cocaine addiction.
- It was not the determining factor in major crimes.
- It was not widespread among schoolchildren and was not linked to juvenile delinquency.
- Publicity about catastrophic effects in New York City was unfounded.
Together, the findings on addiction and harder drugs rejected what would later be called the gateway theory. The report also found that most users were not the people federal propaganda described; the Points analysis notes that it undercut claims that users were mainly migrant workers or jazz musicians.
Why It Mattered
The report landed seven years after Congress passed the Marihuana Tax Act on the strength of Anslinger’s testimony that marijuana drove users to madness and crime. Here was a medical academy, working for the mayor of the country’s largest city, saying the evidence did not support that. Anslinger, head of the Federal Bureau of Narcotics, called the report “unscientific,” denounced La Guardia and the doctors involved, and said no one should conduct further cannabis research without his permission, according to the committee’s history and Scientific American.
What Happened Next
Federal policy moved in the opposite direction. Congress raised drug penalties with the Boggs Act of 1951 and the Narcotic Control Act of 1956, and the Controlled Substances Act of 1970 placed marijuana in Schedule I. When President Nixon’s National Commission on Marihuana and Drug Abuse, the Shafer Commission, reported in 1972, it reached conclusions close to La Guardia’s: it called earlier claims about marijuana’s dangers largely false and found no confirmed causal link between marijuana and heroin use. Nixon did not adopt its recommendation to decriminalize personal possession. Our history of marijuana in America follows the full timeline.
Where It Stands in 2026
The report’s home city now has legal cannabis. New York legalized adult use in 2021 with the Marihuana Regulation and Taxation Act, and its first licensed store opened at the end of 2022; see our New York marijuana laws guide. Federally, an April 2026 order moved state-licensed medical marijuana and FDA-approved products to Schedule III, while adult-use cannabis remains in Schedule I. Our federal law guide covers the details.
La Guardia Committee Report FAQ
What was the La Guardia Committee Report?
A 1944 study, “The Marihuana Problem in the City of New York,” prepared by the New York Academy of Medicine for a committee Mayor Fiorello La Guardia appointed in 1939. It examined marijuana use in the city and its effects on users.
What did the La Guardia Report find?
It found that marijuana did not cause addiction in the medical sense, did not lead to heroin, morphine or cocaine use, was not a major cause of crime, and was not widespread among schoolchildren.
How did the federal government respond?
Harry Anslinger of the Federal Bureau of Narcotics called the report unscientific and attacked its authors. Federal penalties grew harsher in the 1950s.
How many people were in the clinical study?
77: 72 volunteer subjects under the city Department of Correction’s supervision and five controls.
Originally reported by The Weed Street Journal; rewritten and updated in October 2026 with what happened next.
