High-strength cannabis linked to addiction and mental health problems

Largest ever study into the health effects of different types of cannabis highlights concerns about stronger forms of the drug. As the strength or potency of cannabis products has increased internationally over the years, so have rates of people being treated for cannabis addiction, say the authors of a new study. Researchers from the Addiction and Mental Health Group at the University of Bath (UK) systematically analysed the relationship between the types of cannabis people use and their addiction and mental health problems. Their work draws on 20 studies involving almost 120,000 people. After alcohol and nicotine, cannabis is the most widely used drug globally. Latest estimates from the UK suggest that over the last year around one in five 16-24 year olds had used cannabis. Cannabis potency refers to the concentration of tetrahydrocannabinol (THC) in cannabis - the key psychoactive drug it contains.