A recent UK Home Office report sounded the alarms about the identification of 17 previously 'unknown' drugs that had never before been seen in the UK - setting off a legislative rush to ban these so-called 'legal highs'.

The UK is far from alone. The European Monitoring Centre for Drugs and Drug Addiction has consistently identified new drugs throughout Europe, which only appear to rise exponentially each year.

While these substances can inspire fear in the public, perhaps even more alarming are the solutions proposed in a UK Home Office report, which may merely accelerate a downward spiral of unknown substances entering the global marketplace.

'Legal highs' - or what the UK government calls, 'new psychoactive substances' - generally refer to 'designer drugs' that 'mimic the effects of controlled drugs by slightly altering their chemical structure in order to circumvent existing controls.'

These drugs are untested, potentially dangerous and difficult for lawmakers to keep track of because as soon as they're banned, a chemist only has to develop a new chemical cocktail that produces highs similar to drugs banned by national or international law.

The chronic or acute effects of these new chemical structures are largely unknown and the so-called 'legal' drug is very often more dangerous than the original. For example, throughout Europe 'the list of newly notified substances was dominated by synthetic cannabinoids.' Thus people are ingesting potentially toxic combinations of chemicals to get a high similar to the effects of marijuana - in order to bypass problems of availability or legality (though the term 'legal high' is misleading as many of these substances are created with substances that are actually illicit).

Which is why the Home Office's rush to ban all these 'legal highs' may actually make things worse.

While the goal of protecting public health is laudable, lawmakers run the risk of spurring the creation of new untested, even more dangerous, drugs to circumvent the law. The numbers appear to bear this out - as soon as one 'designer drug' is identified, new substances soon follow.

The European Monitoring Centre for Drugs and Drug Addiction writes, 'In 2011, 49 new psychoactive substances were officially notified for the first time in the European Union through the information exchange mechanism ... This represents the largest number of substances ever reported in a single year, considerably up from 2010 (41 substances) and 2009 (24 substances).'

The governments in Europe can and should be expected to keep a watchful eye on new and potentially harmful substances and take legislative action if necessary. But they should also be careful to avoid inadvertently provoking the creation of an even more dangerous marketplace for 'designer drugs'.

Over a thousand legal highs' outlets were shut down in Poland in 2010 in a single October weekend. The government pronounced a victory in the war against new dangerous drugs. Almost two years later, the media have reported that 'legal highs' are back and the numbers of patients in toxicological wards are again high. The experience shows that in the era of internet stores, it is exceedingly difficult to control these kinds of products.

There are some that will propose regulation - with tighter controls over drugs that carry higher risks - or other 'alternative policy and legislative approaches to drug control'.

However, what ultimately matters is that governments are aware of the potential consequences of any policy, whether regulation or prohibition of these substances. That should involve an impact assessment of these policies, which would preferably include an analysis of drugs that have already been prohibited to help policymakers and the public understand potential outcomes.

Mainly, it should consider the possibility that these laws may result in the development of new, untested drugs. It should also consider whether existing prohibitions are leading to the desired outcomes and if new prohibitions are working or whether they are creating a host of unintended consequences.

Open Society Foundations Global Drug Policy Program has produced several recent reports on positive models in drug policy. The Czech Republic is one such example of a government that introduced high-quality research to study the impact of its laws.

Such research can inform policymakers on whether or not laws promote better health outcomes, decrease availability and use as well as reduce other costs associated with drugs. When the Czech Republic recognised that harsher criminal sanctions introduced in the late-1990s did none of these things, the government introduced much-needed reforms. This approach has resulted in low levels of HIV prevalence among people who inject drugs and more successful treatment services.

The point is only that any new policy should be guided by evidence. Because misguided policies can be as dangerous as the drugs they are trying to control.

Kasia Malinowska-Sempruch is the director of Open Society Foundations Global Drug Policy Program

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