The government has said it will review all academic and clinical studies linking cannabis use to mental health problems.

Reports suggest it is now generally agreed among doctors that cannabis is an "important causal factor" in mental illness.

Stakeholder Response: SANE

Marjorie Wallace, Sane chief executive, said: "Sane has campaigned for 18 years about the destructive link between cannabis and schizophrenia and that professionals and governments had ignored years of mounting evidence.

"Far from it being a relatively harmless recreational drug - for vulnerable people, especially teenagers, the innocent spliff in the playground, or chilling out, could trigger a journey of lifelong disintegration."

Stakeholder Response: Hubbard Foundation

A spokesman for the Hubbard Foundation said: "Research has demonstrated that the single most destructive element present in our current culture is drugs. 

"The acceleration of widespread use of drugs, such as LSD, heroin, cocaine, 'angel dust', marijuana and a long list of others has contributed heavily to a debilitated society.  Reportedly, some of these can cause brain and nerve damage.

"Marijuana, for example, so favoured by college students who are supposed to be getting bright today so they can be the executives of tomorrow, has been reported capable of causing brain atrophy.  L. Ron Hubbard wrote the above back in the 60’s and it still holds true today."