Nearly all cannabis on Britain’s streets is now super-strength skunk that could be fueling the rise in mental health problems, scientists have warned. Researchers at King’s College London tested almost 1,000 police seizures from Kent, Derbyshire, Merseyside, Sussex and the capital in 2016, and found 94 percent were of a dangerously high potency. In 2005, just 51 percent of cannabis sold on the street was sinsemilla, also known as skunk. Dr. Marta Di Forti, Medical Research Council Clinician Scientist at King’s College warned that the powerful drug placed Britain’s 2.1 million cannabis users at risk of schizophrenia, bipolar disorder, depression,...