Lester Grinspoon

Lester Grinspoon (June 24, 1928 – June 25, 2020) was an American psychiatrist and associate professor of psychiatry at Harvard Medical School, renowned for his empirical research on cannabis that demonstrated its lower toxicity and addictiveness relative to alcohol and tobacco, challenging the scientific basis for its prohibition.

Grinspoon's investigations began in the 1960s amid rising concerns over marijuana use, culminating in a 1969 Scientific American article that exposed the lack of evidence for claims of its severe physical or psychological harms, such as psychosis or gateway effects. This work informed his influential 1971 book Marihuana Reconsidered, which systematically reviewed available studies and argued that criminalization rested on anecdotal fears rather than data, advocating instead for regulation akin to other substances. Later, in Marihuana: The Forbidden Medicine (1993, co-authored with James B. Bakalar), he documented cannabis's therapeutic applications for conditions including chemotherapy-induced nausea—partly inspired by his son's leukemia treatment—and pain management, drawing on historical medical uses and patient reports where empirical trials were restricted by law.

Lester Grinspoon was born on June 24, 1928, in Newton, Massachusetts, to Simon and Sally Grinspoon. His father, Simon, born in 1898 in Russia, immigrated to the United States around 1900 and pursued varied occupations including real estate, law (after passing the bar exam without a full degree), manufacturing at Raytheon, and small boat building. Sally, previously divorced, married Simon in the early 1920s. The family was of Russian-Jewish descent and resided in Auburndale and later Newton Center, facing economic hardship and prevalent antisemitism during Grinspoon's upbringing.