Image copyright Getty ImagesMost cannabis being sold illegally in the UK is super-strength skunk linked to a higher risk of psychotic mental health episodes, an analysis of 995 samples seized by the police suggests.
Types of cannabisThere are three main types of street cannabis – hash (hashish or resin), herbal cannabis (weed, grass or marijuana) and high-potency cannabis or skunk.
Hash is made from the resin of the plant, while herbal cannabis is made from the dried leaves and flowering parts of pollinated cannabis plants.
They analysed police seizures of cannabis from London, Kent, Derbyshire, Merseyside and Sussex in 2005, 2008 and again in 2016.
THC levels in skunk remained fairly constant over the decade.