How THC Went From Illegal Drug to Active Medical Research Subject in the United States | Research

The takeaway

A historical review traced how federal drug laws, anecdotal patient reports, lobbying efforts, and state-level research acts combined to move THC from prohibition into active medical investigation by 1981.

Read this if you want to understand the legal and political history behind medical cannabis research in the United States.

25 states passed therapeutic cannabis research acts by 1981

What the researchers found

The path from cannabis prohibition to medical research was shaped by three key pieces of federal legislation: the Marihuana Tax Stamp Act of 1937, the Controlled Substances Act of 1970, and the Federal Food, Drug and Cosmetic Act of 1962.

Starting in 1968, Congress directed initial studies toward understanding long-term cannabis use in humans. By the early 1970s, research expanded to include medical applications. This shift was driven by several converging forces: anecdotal reports from patients finding relief from chemotherapy nausea and glaucoma, lobbying from advocacy groups pushing for legalization, and the passage of Controlled Substances Therapeutic Research Acts by 25 states.

The review documented approved investigational new drug (IND) applications across four therapeutic categories and mapped the components of the research laws passed by all 25 states that enacted them.

Why it matters

This review documents a critical transition period in American cannabis policy. Understanding how therapeutic research authorization developed, through the interplay of federal law, state legislation, patient advocacy, and scientific interest, provides context for the much larger medical cannabis movement that followed.

The numbers in context

25 states passed Controlled Substances Therapeutic Research Acts. Four therapeutic categories had approved INDs. Key legislative dates: 1937, 1962, 1968, 1970.

How the study worked

Historical and legislative review covering U.S. cannabis policy from the 1937 Marihuana Tax Stamp Act through 1981. Included a listing of approved INDs, comparative chart of 25 state research laws, and bibliography.

What this study cannot tell us

As a historical review focused on the U.S. regulatory landscape, it does not evaluate clinical evidence directly. The 25-state comparison covers legal frameworks, not research outcomes.

How to read the evidence

A historical and legislative review providing policy context rather than clinical evidence.

When this study was published

Published in 1981. The medical cannabis landscape has changed dramatically, with most states now having some form of medical or adult-use cannabis law.

The bigger picture

The state-level research acts documented here were precursors to the medical marijuana laws that began passing in 1996 (California's Proposition 215). The tension between federal classification and state-level therapeutic access described in this 1981 review remains the central conflict in U.S. cannabis policy today.

Questions still open

Did the state research acts produce meaningful clinical data? How did the IND pathway shape the trajectory toward dronabinol approval? What role did patient anecdotes play versus controlled evidence in driving legislative change?

Common questions

What drove the shift toward medical cannabis research?

A combination of patient reports about nausea and glaucoma relief, advocacy group lobbying, passage of state research laws, and congressional directives to study long-term cannabis effects.

How many states had research programs?

By 1981, 25 states had passed Controlled Substances Therapeutic Research Acts allowing some form of medical cannabis investigation.

Read the original research

THC therapeutic research by independent and state-sponsored investigators: a historical review.

Journal of clinical pharmacology, 21(S1), 113S-121S

View on PubMed ↗

Citation

Scigliano, J A. (1981). THC therapeutic research by independent and state-sponsored investigators: a historical review.. Journal of clinical pharmacology, 21(S1), 113S-121S.