It is difficult to assess the true harm caused by cannabis. There are limits to the scope for information on its effects because of its illegal nature1. However, it is widely acknowledged that there are links between cannabis use and mental and physical health problems2. It is also widely acknowledged that excessive cannabis use can harm relationships and prevent people from acting as functional members of society. Cannabis is generally smoked with tobacco and cannabis users are more likely to drink alcohol. Regardless of whether cannabis itself is worse for you than tobacco or alcohol, it is still bad for you and therefore it should remain illegal.  The reason alcohol and tobacco are legal is not related to their effect on our health. They (alcohol and tobacco) are legal as they have existed in this country since long before laws were passed in relation to health and were far more popular than cannabis so it would have been much harder to ban them. Cannabis is illegal not because it supposedley is worse but because it is was less commonly consumed. That said, alcohol and tobacco are irerelvent in this debate.  1 Wolff , J. (2009, December 1). The art and science of evidence about drugs. Retrieved July 20, 2011, from Guardian:  2 Frank. (n.d.). Cannabis. Retrieved July 20, 2011, from Talk to Frank: