Cannabis and mental health in the U.K.

Two million people in the UK smoke cannabis. Half of all 16 to 29 year olds have tried it at least once. In spite of government warnings about health risks, many people see it as a harmless substance that helps you to relax and ‘chill’ – a drug that, unlike alcohol and cigarettes, might even be good for your physical and mental health.  Physical health problems  The main risk to physical health from cannabis is probably from the tobacco that is is often smoked with. Is there such a thing as ‘cannabis psychosis’? Recent research in Denmark suggests that yes, there is. It is a short-lived psychotic disorder that seems to be brought on by cannabis use but which subsides fairly quickly once the individual has stopped using it. It's quite unusual though – in the whole of Denmark they found only around 100 new cases per year. What about skunk ?  The amount of the main psycho-active ingredient, THC, that you get in herbal cannabis varies hugely from as low as 1% up to 17%.  The newer strains, including skunk, can have up to 24%.  The newer varieties are, on the whole, two or three times stronger than the weed that was available 30 years ago, but still not as strong as the hash of the old days .