2.1     The earliest known reference to cannabis is in Assyrian tablets of the seventh century BC. It has thus been in use for at least 2600 years. Like very many other herbs, it has been used medically for a wide variety of ailments, especially throughout Asia and the Middle East. The mild euphoria that it induces led to its use as an intoxicant, perhaps most notably in countries where Islam prohibited the use of alcohol.

2.2     In Western medicine, it appeared in the Herbal (i.e. pharmacopoeia) of Dioscorides of about 60 AD, and in all subsequent herbals. The 16th century saw a detailed interest in cannabis, with reports of it and its usages being sent back by many travellers to the East, and the number of possible uses given in the herbals doubled. In England, the Herbal of John Gerard (1597) recommended it as it "consumeth wind and drieth up seed [i.e. semen]", and quoted Dioscorides as recommending it for easing the pain of earache and for the treatment of jaundice. Nicholas Culpeper, in his Herbal (1653), gave the same indications for the use of cannabis seeds, and also recommended the decoction of the roots, as this "allayeth inflammations, easeth the pain of gout, tumours or knots of joints, pain of hips...".

2.3     In these and other early Herbals, each medicine was said to have multiple uses, often without justification. More critical views ultimately prevailed, but only slowly. Thus by 1788 the New Edinburgh Dispensatory still included three quarters of the entries of Dioscorides, but excluded most animal products. Such exotic remedies as "scrapings of an elephant's tooth", "dust from the walls of a wrestling school" and, remarkably, as a cure for quartan malaria, "seven bed bugs in meat and beans", had been eliminated. The loss of the animal products and most of the minerals left the 1788 New Dispensatory consisting mainly of herbal remedies. There was little change for 150 years, and the British Pharmacopoeia of 1914 included most of the contents of the volume of 1788. But the situation was about to change radically, with the rise of synthetic pharmaceutical chemistry.

2.4     Meanwhile, in 1833 Samuel Carey in his Supplement to the Pharmacopoeia and Treatise on Pharmacology advised that cannabis could be used to make "an agreeable intoxicating drink". This is the only British reference to cannabis as an intoxicant known to us from this period.

2.5     Cannabis was reintroduced into British medicine in 1842 by Dr W O'Shaughnessy, an army surgeon who had served in India. In Victorian times it was widely used for a variety of ailments, including muscle spasms, menstrual cramps, rheumatism, and the convulsions of tetanus, rabies and epilepsy; it was also used to promote uterine contractions in childbirth, and as a sedative to induce sleep. It is said to have been used by Queen Victoria against period pains: there is no actual proof of this at all, but Sir Robert Russell, for many years her personal physician, wrote extensively on cannabis, recommending it for use in dysmenorrhoea. It was administered by mouth, not by smoking, but usually in the form of a tincture (an extract in alcohol). Cannabis extracts were also incorporated in many different proprietary medicines.

2.6     "People were well aware at that stage that [cannabis] was an unpredictable drug" (Edwards Q 26). The advent of a host of new and better synthetic drugs led to the abandonment of many ancient herbal remedies, including cannabis. Thus in the British Pharmacopoeia of 1932 no fewer than 400 herbal remedies were omitted, among them cannabis, extract of cannabis and tincture of cannabis—though all three remained in the British Pharmaceutical Codex of 1949[].

2.7     Until 1968, the only control of medicines in the United Kingdom (other than those regarded as dangerous) was provided by the pharmacopoeias, which set quality standards for the preparation of drugs. The Medicines Act 1968 was enacted following the thalidomide tragedy: it gave the Government power to license pharmaceutical companies, and individual products and clinical trials. It also established the Medicines Commission and the Committee on the Safety of Medicines, to advise the Government on the exercise of their new powers. Existing drugs received "licences of right". The licensing powers are now exercised through the Medicines Control Agency (MCA). Doctors may prescribe an unlicensed drug, or a licensed drug for an unlicensed indication ("off-label"); but they do so at their own risk, and without the benefit of the surveillance for adverse effects which is conducted in respect of licensed medicines through the "yellow card" system.

2.8     Drug abuse has been the subject of international conventions since 1912. In 1961 these were consolidated and brought up to date by the UN Single Convention on Narcotic Drugs. Cannabis and cannabis resin were listed in Schedule IV, which entitled (but did not oblige) parties to adopt "special measures of control", and to ban them altogether "except for amounts which may be necessary for medical and scientific research only, including clinical trials..." (Article 2.5). According to the Home Office (p 150), this reflected "WHO's view that the drug was widely abused, had no therapeutic value and was obsolete in medical practice". Under the Dangerous Drugs Act 1964 (shortly consolidated by the Dangerous Drugs Act 1965), which implemented the Convention in the United Kingdom, cannabis was still able to be prescribed, though subject to certain controls. The tincture received a "licence of right" under the Medicines Act 1968; doctors were therefore still able to prescribe it.

2.9     The scale of drug abuse increased dramatically during the 1960s. In 1971 the UN adopted a further Convention on Psychotropic Substances; and the United Kingdom enacted the Misuse of Drugs Act 1971, which repealed the Act of 1965 and other enactments, replacing them with a more comprehensive and flexible regime. Cannabinol and its derivatives including THC (the chemical which gives cannabis its psychoactive properties—see Chapter 3) appeared in Schedule I to the Convention, and parties were therefore obliged to ban them "except for scientific and very limited medical purposes by duly authorized persons" (Article 7(a)). In 1973 the licences of right granted in 1968 were reviewed, and the original Misuse of Drugs Regulations (SI 1973 No. 797) were made under the 1971 Act. Cannabis's licence of right was not renewed, and the Regulations listed cannabis, cannabis resin and cannabinol and its derivatives in Schedule 4—which is now Schedule 1 to the Misuse of Drugs Regulations 1985 (No. 2066)—thereby prohibiting medical use altogether.

2.10     According to the MCA, by 1973 there was "insufficient evidence" to support medical use of the tincture (Q 174), and it was rarely prescribed except to patients who were already drug misusers. The Parliamentary Under-Secretary of State for Health told the Commons on 14 January 1998 (col. 320), "It was rarely used and, when it was, it was used mainly for its sedative qualities. Advice at the time from the World Health Organization was that cannabis was no more effective than any other available drug in treating the conditions for which it was used, so its use was stopped." According to the Department of Health, there was also a problem of diversion to recreational use through bogus prescriptions (Q 174).

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