Katrina Robertson and Jolene Crawford: Banning drugs is not the way to manage substance dangers

We know only too well the pain of losing someone in such a futile manner and the questions that come in the search for clues as to how or why this could happen to a bright, young person.

We understand the need to apportion blame and the desire to prevent any other family going through a similar nightmare. But however tempting it was to call for all drugs to be banned, we decided to educate ourselves about legal and illegal drugs and the real issues regarding these substances. What we discovered surprised us greatly and resulted in the founding of Transform Drug Policy Foundation Scotland (TDPF), a campaign for the control and regulation of illegal and legal drugs.

As busy mothers, taking on this challenge was not ideal and it's painful for the family each time we speak out, but we discovered that current drug policy has no factual basis. The individuals who create these policies acknowledge in private that drug prohibition is a disaster but none will put their heads above the parapet. Most importantly, we found that the government has the power to make changes to drug policy to transform the lives of individuals, families and society as a whole – regulation.

We have gathered supporters, including our patron Iain Banks, the former High Court judge Lord McCluskey, the former bishop of Edinburgh Richard Holloway, consultant addictions psychiatrist Fraser Shaw, retired Strathclyde Police inspector Jim Duffy, as well as former users, drugs workers and other bereaved families. In the past couple of weeks, since mephedrone has been in the news again, we have worked closely with a supporter whose son died as a result of using a legal high, continuing our campaign to raise awareness of the increased dangers of criminalising such substances.

All the evidence reveals that the prohibition of drugs is hugely expensive and actively counterproductive. The only beneficiaries are the suppliers who are gifted an enormous, unregulated market. In Britain for every 1 spent on the "war on drugs", 7 is spent on policing, prisons, courts and the social services resulting from the need to deal with the negative consequences of criminalisation and the illegal market. This costs Scotland about 3.5 billion a year – something that we can ill afford. Despite this, drugs today are cheaper, stronger and more available than ever .

When a legal high such as mephedrone is banned, another substance is quickly manufactured to replace it, which will then be sold openly, like its predecessor, without regard to age and without safe use instructions. The result is more tragic and pointless deaths. Moreover, banning mephedrone on the grounds that it can be fatal logically means alcohol and tobacco (which kill 100 and 300 a day in the UK respectively) should be dealt with similarly.

So rather than blindly falling in behind the common response to these isolated incidents which are sensationalised and misunderstood in the media, Transform Drug Policy Foundation is calling for the UK government to conduct an independent and comprehensive impact assessment which should review all the real evidence relating to how best to safely manage drugs.

After decades of counter- productive failure, we urgently need a meaningful debate on alternatives to prohibition – policies and laws based on evidence and public health principles, not failed punitive ideologies.

• Jolene Crawford and Katrina Robertson are co-founders of TDPF Scotland.