Charlie Lloyd suggests more research is needed regarding the relation of cannabis use to unemployment, educational under achievement, homelessness and motivation (More study needed into cannabis impact, Readers' Letters, October 27).

There has been 30 years of research in an attempt to link cannabis use with "amotivational syndrome". No such link has been established.

It is very easy to blame cannabis for many of society's ills, particularly as it is the most commonly used illegal substance. Links with mental illness dominate the cannabis panic in the media, but the research is being misrepresented to suit a political agenda.

What is presented to the public is far from accurate and factual.

It is clearly unsuitable for very young people to use any drug, legal or illegal, on a regular basis. But heavy cannabis use - as with alcohol abuse - is more likely to be a symptom of a problematic life, rather than the cause of the problems.

Years of grossly exaggerated claims about the harms of cannabis leave the government with little credibility to give advice. Whatever the harms may be to a tiny minority of users, these are clearly health issues and not issues of criminality.

Prosecution and potential imprisonment of non-violent cannabis users who do no harm to others is a moral dogma which has been failing for decades.

Unfortunately, our gutless politicians are incapable of dealing with the issue properly, preferring instead to play party politics with a totally discredited classification system.

Steve Clements, The Legalise Cannabis Alliance, York.