The NHS advises that regular cannabis use increases the risk of developing a psychotic illness and the risk is higher when use begins at a young age

Cannabis is more likely to be taken by schizophrenics trying to self-medicate than to cause the disorder, according to research.

The largest study yet of genes and predisposition to schizophrenia and cannabis use looked at anonymised data from 180,000 people. The researchers identified 35 genes linked to cannabis use, with the strongest associations in CADM2. “CADM2 has already been associated with risky behaviour, personality and alcohol use,” said Jacqueline Vink, of Radboud University in the Netherlands, the study’s lead author.

In the paper, published in Nature Neuroscience, the researchers wrote: “We found weak evidence for a causal link from cannabis use to schizophrenia and much stronger evidence for a causal link from schizophrenia to cannabis use. This suggests that individuals with schizophrenia have a higher