WHILE cannabis’s potential for harm has been well-documented and numerous studies show some therapeutic benefits of medicines synthesised from the drug, the British government is reviewing the law on medicinal use of cannabis.

Man’s relationship with marijuana goes back millennia. Most ancient cultures were acquainted with the drug and hemp crops were first grown over 10,000 years ago. The Chinese used cannabis for medicinal purposes 5,000 years ago, followed by other ancient civilisations including the Egyptians, Greeks, Romans and medieval Arabs who also used the drug to treat a wide array of ailments.

Cannabis has been associated with both love and war — the legendary Arabian Nights folk tales note the narcotic’s aphrodisiac properties, while the Hashshashin (“hashish smoking”) warriors, a 11th-13th-century Shi’ite sect based in Persia, from which the English word assassin mistakenly derives, were given cannabis to induce a hypnotic state and eliminate the fear of death. More recently, during World War II US scientists found a potent extract of marijuana that could be used as a truth serum.

The recreational use of cannabis was prohibited across much of the world in the early 20th century (1928 in the UK and the early 1930s across the US), around the same time as a number of other stronger narcotics, such as opium, were being banned.

Regardless of the real adverse health effects of smoking cannabis, US print and film media campaigned to demonise the drug by playing on societal prejudices and associating its use with newly arrived Mexican immigrants. Other crass propaganda from the US’s newly created Federal Bureau of Narcotics’ first commissioner Harry Anslinger blamed the drug for causing “white women to seek sexual relations with Negroes [and] entertainers” and claimed it was “more dangerous than heroin or cocaine,” “leads to pacifism and communist brainwashing” and “makes darkies think they’re as good as white men.”

Since the 1930s, nine US states and two countries have legalised cannabis for adult recreational use — Uruguay in 2013 and Canada in June 2018. The latter nation approved the medicinal use of cannabis in 2001. A number of countries now allow the prescription of cannabis-based products for medicinal use. For example, 17 EU member states approve the prescription of one such medicine to treat muscle spasticity occurring in multiple sclerosis.

Medicines derived from cannabis have proven effective in treating a number of other ailments including chronic pain, glaucoma, and nausea and vomiting after chemotherapy. Early studies also suggest that some compounds found in cannabis may slow the progression of Alzheimer’s disease and certain types of cancer.

The British government decided to review the law on the medicinal use of cannabis following recent high profile and emotive cases involving children suffering from severe forms of epilepsy, who struggle to obtain cannabis oil as a treatment to reduce seizure frequency.

The government has actioned a review to investigate which cannabis-based medicines might have therapeutic potential with a view to sanctioning their use. Professor Dame Sally Davies, the government’s chief medical adviser, favours a change to British law allowing doctors to prescribe cannabis-based products for medicinal purposes, stating: “There is now … conclusive evidence of the therapeutic benefit of cannabis-based medicinal products for certain medical conditions and reasonable evidence of therapeutic benefit in several other medical conditions.”

There is a well-documented association between recreational cannabis use and mental illness, the correlation being stronger with respect to heavier or younger users of the drug.

The ingredient THC (tetrahydrocannabinol), responsible for causing the “high” effect is associated with an increased risk of developing psychosis or schizophrenia. A large-scale study carried out in Sweden involving 50,000 conscripts found that those who had tried cannabis before the age of 18 were almost 2.4 times more likely to develop schizophrenia later in life compared with those who had abstained. The study also found that the heaviest cannabis users had a sixfold increased risk of developing schizophrenia compared with non-users.

In addition to the harmful THC compound, cannabis also contains over 60 cannabinoid compounds (some of which act antagonistically to one another). Further research is needed to discover and exploit any therapeutic potential they may possess. One of these compounds, cannabidiol (CBD), appears to negate the psychosis-inducing effects of THC and is itself begin tested as a treatment for schizophrenia.

The “strength” of cannabis (the amount of THC) has been increasing across Europe and the US in recent years. 94 per cent of the cannabis seized by British police in 2016 was the strong (skunk) variety compared with 51 per cent in 2005. Research indicates that casual users of skunk, which contains a high percentage of THC and very little CBD, increase their risk of experiencing a psychotic episode threefold, whereas heavy users have a fivefold greater risk.

Allowing British doctors to prescribe medicines synthesised from cannabis would undoubtedly be a positive decision. Further research is also needed to explore the properties and deduce the benefits of the myriad compounds contained within cannabis. Cannabis itself is both a virtue and a vice.

The recreational use of cannabis, especially the ubiquitous THC-rich variety, is a public health concern and costs police millions of pounds and thousands of hours at a time when police numbers are at a record low and the NHS is under excessive strain.

In Uruguay, drug-associated crime reportedly fell by 20 per cent after cannabis was legalised. The British government could raise vital funds for the NHS and other public services if a low-THC/high-CBD version of the drug is sold from government-run pharmacies to adults only.

With the state controlling the production, supply and sale of cannabis, not only would British cannabis dealers and foreign criminals involved in trafficking the drug into the country be deprived of profit, but police and the courts could focus their resources cracking down on those who drive under the influence of cannabis, supply it on the black market, or provide the drug to children and pose a risk to society.

Tomasz Pierscionek is a doctor specialising in psychiatry. He was previously on the board of the charity Medact and is editor of the London Progressive Journal. This article originally appeared at on.rt.com/99zv