As part of Nechama Brodie’s research into our November issue’s Special Report – Legalise Weed? Are We High? – she asks, is marijuana medicine?

Medical marijuana isn’t exactly a “new” thing. Humans have been using cannabis and its derivatives for religious, recreational and therapeutic purposes for thousands of years. But, unlike aspirin and morphine – two other plant-based substances that have been used since at least the time of the Pharaohs – studies of cannabis’s palliative potential were almost completely side-lined, even suppressed, by anti-drug policies introduced in the early 20th century.

South Africa was one of several countries that actively lobbied for cannabis (or Indian hemp, as it was referred to) to be included on the list of controlled narcotic substances, under the 1925 International Opium Convention treaty. Although the measure was presented as one intended to prevent the harm of addiction, it had very clear racial undertones: in South Africa, the United States, and in India, cannabis had been blamed for causing madness, triggering violent – even homicidal – tendencies, and contributing to general “moral degeneration” among the [black, Mexican and African American, and Indian] working classes.

Hyped up fears around “dagga madness” or the “marijuana menace” were used restrict and then outlaw the use of cannabis altogether. These same laws didn’t just make it illegal to consume cannabis; they also made it near impossible for doctors and medical researchers to study the plant in any meaningful way.

At the same time as cannabis was being banned, new drug and medicine safety protocols were being established – what would evolve into controlled clinical trials, designed to establish both the safety and the effectiveness of any medicines used to treat humans.

Because cannabis was effectively excluded from such studies, there was to be little “science” that would prove – or disprove – several thousand years of anecdotal information (the cannabis activism lobby would argue otherwise; but that’s another debate).

It wasn’t until 1964 that the principal psychoactive ingredient in cannabis, Tetrahydrocannabinol or THC, was first isolated and identified by a team of Israeli scientists. At around the same time, a pair of Jamaican scientists – Professor Manley West, a pharmacologist, and Dr Albert Lockhart, an ophthalmologist – began investigating the potential use of cannabis to treat the eye disease glaucoma. Their study was prompted by the pair’s observations that their patients who smoked cannabis or drank “ganja” tea appeared to have lower incidence of glaucoma or reported better vision. West and Lockhart later developed and marketed a therapeutic eye drop derived from cannabis.

Lockhart and West were, of course, not the only doctors or researchers to take note of reported beneficial side effects of marijuana, or to observe the effects of cannabis on user populations, but formal medical studies with human patients were still inhibited by the drug’s contraband status – and, also, because the most common and effective way of consuming cannabis was through smoking, which raised its own health concerns.

In the 1990s interest in the potential medical applications of cannabis and cannabinoids was revived after the discovery of the endocannabinoid system –internal cannabinoids and receptors that are found throughout the body – in humans.

The human body naturally produces its own cannabinoids (endocannabinoids), and the same receptors also respond to phytocannabinoids, or cannabinoids of plant origin (like THC), as well as synthetic cannabinoids.

This, together with a gradual shift in public perception around cannabis (and around the so-called War on Drugs), resulted in the first wave of proposed legislative changes in several American states, allowing the prescription of marijuana for medical use. Nearly twenty years later, this was what the late MP Mario Oriani-Ambrosini campaigned for in South Africa, after he was diagnosed with lung cancer and began (illegally) using cannabis as a treatment.

In countries or states where medical marijuana has been legalised, doctors are able to prescribe marijuana for a wide range of ailments including chronic pain; muscle spasms associated with multiple sclerosis; nausea and vomiting (frequent side effects of chemotherapy); as an appetite stimulant for chronic wasting conditions (a common complication with HIV); to relieve eye pressure in patients with glaucoma; and to help patients with Crohn’s disease. Cannabis extracts are also being used to treat patients with epilepsy, asthma, anxiety, insomnia and even depression.

But even there, medical marijuana remains a grey area: the United States’ Food and Drug Administration (FDA), for example, has “not approved [botanical marijuana or its extracts] as a safe and effective drug for any indication” (it has approved one formulation with a synthetic cannabinoid) – and is unlikely to do so until the completion of formal drug trials.

While the FDA states that it supports “those in the medical research community who intend to study marijuana” the reality for researchers appears to be less straightforward, and there are allegations that the country’s Drug Enforcement Agency (DEA), in particular, makes it difficult to obtain the necessary approvals.

Despite all the legal, administrative and other obstacles, it’s unlikely that humans are going to press pause on millennia of self-medication while they wait for official approval. If anything, new research, changes in legislation, and the rapid dissemination of (expert and other) information through the internet seems to have spiked interest in therapeutic applications of cannabis – and, even where it’s not legally available, interested patients will almost certainly turn to extra-legal means, as many have done in the past.

Although early research is promising it’s maybe (definitely) too soon to hail cannabis as the ultimate panacea. As with any medicine – even the supposedly mild over-the-counter stuff, or ones with “all natural” ingredients (natural does not automatically equal safe, or less-harmful) – it’s still essential to get medical input before trying anything new, particularly when it’s something that comes without a package insert. We know you never read those things anyway. But you should.

Download the the entire Special Report – Nov 2014