Cannabis has been used for thousands of years for industrial, recreational, religious, and medicinal purposes. Once valued as a versatile herbal medicine, cannabis has held a volatile place in the medical field since the beginning of the twentieth century. Its decline was deeply influenced by economic, social, and ethical factors. Until recently, it seemed the flowering plant was destined to fall by the wayside: it was classified as a substance of abuse, condemned by governments, and contributed to the problems of drug trafficking. However, in recent years, a growing body of research has begun to demonstrate the medicinal potential of cannabis in the treatment of numerous pathologies. Cannabis’ path from praised healing agent to dismissed substance of abuse has now come full circle.
In the second installment of our exploration of the history of cannabis, we look at the early use of cannabis in western medicine.
The Rise of Modern Western Medicinal Interest
The Western world was first introduced to the medicinal uses of cannabis in 1839 by Irish physician William Brooke O’Shaughnessy. Dr. O’Shaughnessy had spent time in Calcutta, where he observed people using cannabis for a number of purposes including digestive system support, improvement of their over-all sense of well-being, and as a narcotic. Impressed, he began to test the plant’s effects in animals, becoming the first person to apply the experimental methods to the study of cannabis. Based on his experiments, he ascertained that the plant was safe for use and made extracts of cannabis resin which he placed in pills or dissolved in alcohol. He administered these preparations to select patients who suffered from epilepsy, rheumatisms, cholera, or tetanus. He deduced the plant had analgesic and myorelaxant properties. His work was of critical importance in introducing Indian hemp to British and North American physicians (O’Shaughnessey, Prov Med J Retrosp Med Sci, 1843 ; Pisanti, Trends Pharmacol Sci, 2017; Pain, Nature, 2015).
Following O’Shaughnessy’s work, systematic research on marijuana began to proliferate in the Western World. During the second half of the nineteenth century and the first decades of the twentieth, over a hundred studies were published in Europe and the United States. Researchers explored the impact of cannabis on pathologies ranging from migraine, neuropathic pain, insomnia, hysteria, and stroke to asthma, emphysema, tetanus, and uterine hemorrhage. Pharmaceutical companies such as Merck and Eli Lily developed analgesic, anti-inflammatory, and anti-spastic drugs using cannabis extracts (Pisanti, Trends Pharmacol Sci, 2017; Russo, Cannabis sativa L. – Botany and Biotechnology, Chap 2, 2017). The presumed impact of cannabis on migraine relief was so promising that in 1915 Dr. William Osler, considered the “Father of Modern Medicine”, stated that when treating migraine, “Cannabis indica is probably the most satisfactory remedy” (Baron, Headache, 2015). It was an exciting time in marijuana research. Unfortunately, just as the research was starting to show promising results, it was about to suffer major legal and social setbacks.
William Brooke O’Shaughnessy (circa 1836).