No more Mr Nice guy: Howard Marks doubts safety of cannabis

Howard Marks, the one-time "King of Dope", is a living icon for campaigners for the legalisation of cannabis. But yesterday he admitted for the first time that he is concerned about links between cannabis use and schizophrenia. Marks, better known as Mr Nice – one of 43 aliases he used when running his worldwide drug empire and the title of his best-selling autobiography – said more medical research into the issue is vital. Marks admitted he was uneasy over growing evidence which suggested that being "stoned and being off your head" may be connected. By that, he meant the temporary high from the drug and long-term mental health illness.

Marks, speaking in a TV interview, said: "I think it is difficult to establish whether these two states are similar. If, as a result of smoking a lot of dope, one becomes schizophrenic, that's reason for concern. If being slightly schizophrenic makes you want to smoke some dope to ease you through the day, I don't think that's a cause for concern. "To find out which of these is true will require research. One has to look into the action [of cannabis] on the brain and what happens."



Marks, who was jailed for 25 years for masterminding a worldwide cannabis smuggling operation, has long been an advocate of drug legalisation. But he admitted that claims that smoking cannabis increases an individual's chance of developing a psychotic illness by 40 per cent gave him "genuine concern". The psychosis threat was especially acute in smokers under the age of 16.

Further research was also needed to discover whether the brain itself used chemicals similar to those found in cannabis in order to counter pain, he said.

You can see the interview here.