In the United Kingdom medicinal drugs and treatments are regulated through the 1968 Medicines Act and illegal drugs through the 1971 Misuse of Drugs Act. The Misuse of Drugs Act defines controlled substances on the basis of their potential harm, taking no account of benefits that users might claim. The distinction between medicines and illicit drugs is, of course, not sharp, and many valuable medicines (including Ritalin, GBH (γ hydroxybutyrate), tranquillisers, and analgesics) turn into dangerous killers when they escape on to the streets.

The Misuse of Drugs Act established the Advisory Council on the Misuse of Drugs (ACMD) “to keep under review the situation in the United Kingdom with respect to drugs which are being or appear to them likely to be misused and of which the misuse is having or appears to them capable of having harmful effects sufficient to constitute a social problem.” The council currently has 33 appointed and co-opted members, with expertise in pharmacology, psychiatry, public health, drug charities, schools, mental health, and forensics. On the basis of extensive reviews and consultations, these experts advise the government on which drugs should be controlled and on their classification as A, B, or C, according to the burden of harm.

Several drugs have …