The Telegraph 15 February 2015
One in four new cases of psychotic conditions such as schizophrenia could be the direct result of smoking extra-strong varieties of cannabis, a major new study concludes.
The finding suggests that about 60,000 people in Britain are currently living with conditions involving hallucinations and paranoid episodes brought on by abuse of high-potency cannabis, known as skunk, and more than 300,000 people who have smoked skunk will experience such problems in their lifetime.
The six-year study, the first of its kind in Britain, calculates that daily users of skunk are five times more likely to suffer psychosis than those who never touch it.
Psychiatrists said there is now an “urgent need” for a drive to educate the public about the risks involved with the substance. It is believed that even newer varieties, some of them more than twice as potent as those currently available on British streets, have already been developed in the Netherlands.
The findings reopen the debate about the classification of cannabis as an illegal drug, with some supporters of liberalisation now considering tougher restrictions on some varieties.