Pubdate: Mon, 16 Nov 1998 Date: 11/16/1998 Source: Independent, The (UK) Author: David Ryan Sir: It is morally wrong to withold proven medical treatment from patients. The great debate is whether cannabis is proven to be medically useful. Further clinical trials, which the Government requires, are unnecessary because if there was a debilitating side-effect then 2000 years of medical usage would have made it apparent ("Cannabis is 'safer than drinking' ", 13 November). Anecdotal and historic evidence proves the superiority of herbal cannabis in the treatment of MS, epilepsy and many other diseases. Cannabis treatment is witheld because the pharmaceutical companies will not make money from a common plant. If cannabis is God's gift to the sick then it is our duty to make sure they can legally obtain it. In the past cannabis has been targeted as a menace and a threat to society; now the media should champion the cause of those who undergo persecution because of a quirk in the law. David Ryan, Keble College, Oxford