Campaigners are calling for the government to investigate the links between cannabis and mental health problems, writes Maria Ahmed. 

Mental health charity Rethink this week asked the health select committee to launch a public inquiry, one year after the Home Office reclassified the drug from a class B to a class C drug.

Rethink chief executive Cliff Prior said there was a “clear need” for more research.

He added: "Reclassification has sent out a mixed and confusing message. There is a strongly-held view that cannabis is risk-free, reflected in the rates of its use among young people.”