The thin white line of future drug control

The UK Government have announced they want to change the drugs law and ban “[any] substance which is capable of producing a psychoactive effect”. It’s a fairly clumsy attempt to tackle the wave of ‘legal highs’ but there’s a little psychopharmacological gem, hidden away, in the Home Secretary’s letter that accompanies the proposed changes.

There’s been plenty of news coverage of the proposed blanket ban, both for and against, and you can read the official documents on the Home Office Psychoactive Substances Bill webpage.

From the government’s point of view, it’s pretty much all they can do. The list of banned drugs has got so large that they’ve decided it is easier to say what isn’t prohibited. So apart from the specifically mentioned exceptions (the respectable dangerous drugs: booze, nicotine, meds) they’ve decided to ban

“[any] substance [that] produces a psychoactive effect in a person if, by stimulating or depressing the person’s central nervous system, it affects the person’s mental functioning or emotional state”

It’s a vague and unhelpful definition that could include half the products in your cleaning cupboard. But it leaves a more interesting question which the Home Secretary is clearly aware of. That is – how do you know a substance is psychoactive at all?

In other words, imagine the police find a suspicious looking white powder but the drug isn’t in their database. New drugs are appearing at about one a week, so it’s a very likely scenario. Working out whether it is psychoactive or not is key for legal purposes.

This issue has clearly already troubled the Home Secretary. In her letter to the Advisory Council on the Misuse of Drugs, the Home Secretary says “I would welcome the Council’s views on how best we can establish a comprehensive scientific approach for determining psychoactivity for evidential purposes.”

But what science tells us is that the only way of confidently working out whether something is psychoactive or not, is to take it.

This is because you can’t confidently predict what a drug will do to the mind from its chemical structure.

We can say some general structures are more likely to be psychoactive than others, but it’s never guaranteed. For example lots of tryptamines are psychoactive but even here structurally very similar drugs may have very different effects.

Some tryptamines – like DMT and psilocybin are powerfully hallucinogenic – other very similar tryptamines – like the drugs used to treat migraines, are not.

As drugs are essentially keys to the ‘locks’ of the brain’s synaptic receptors – even a tiny change might suddenly mean it won’t fit in the keyhole and has no psychoactive effect.

Interestingly, this means both the manufacturers of new psychoactive compounds and the UK government will have the same problem. Because you can’t do a chemical test on a new drug and say for sure it’s psychoactive, and animal tests won’t give you a definite answer, someone has to take it to find out.

Grey market labs in China and Eastern Europe solve this problem by, well, getting someone to take the drugs. Christ knows what the Government are going to do.

Cheeky line of as-yet-untested phenethylamine derivative Home Secretary?