Potent cannabis strongly linked to psychosis
Powerful forms of the drug widely available in London may increase the risk of schizophrenia-like mental illness five-fold, say scientists.
Smoking potent forms of cannabis greatly increases the risk of serious mental illness, a major study has found.
Taking any version of the drug daily was found to triple the chances of developing psychosis.
But using high-potency cannabis containing high levels of the active ingredient THC raised the risk five-fold.
Scientists carried out the study at 11 sites in five countries across Europe, as well as one in Brazil.
They found that the link with psychosis was strongest in London and Amsterdam, where high-potency cannabis is commonly available.
Psychotic conditions such as schizophrenia can have devastating effects, including paranoid delusions and hallucinations.
