Thank you all for your contributions so far
I have also never taken illicit drugs. During my working lifetime, of the many fatal cases I concluded were due to such drug use, none were due to cannabis.
For members of this non-medical forum, I prefer to explain what original articles have said wherever possible. Far from " dumbing down ", it's to save their time. The one from JAMA ( Journal of American Medical Association ) quoted by Tawi2 is, like many others, only obtained by payment / subscription in any case.
JAMA commented as follows:-
" Marijuana smoke contains many of the same constituents as tobacco smoke, but whether smoking marijuana causes pulmonary damage similar to that caused by tobacco is unclear. In an analysis of data from 5115 participants in the Coronary Artery Risk Development in Young Adults study, which included repeated measures of pulmonary function and smoking habits during 20 years of follow-up, Pletcher and colleagues found that occasional or low cumulative marijuana use was not associated with adverse effects on pulmonary function. "
In other words, occasional users may not have breathing difficulties. Dependence is also far less likely with cannabis than other illicit drugs. It's probably easier to give up than tobacco smoking when either / both are infrequent.
http://jama.ama-assn.org/content/current
