I never came across a rule that you can t use a source if its title and main point isn t reflected in the edit That would be very limiting However this is not to say that the material I added does not reflect these The authors discussion on the counteractive effects of cannabis is a major point Regardless what matters is that the details are relevant even if it doesn t summarize the source the only problem is that if they contradict the source Anyway since similar details are in the article I don t dispute the deletion However I would suggest that you define what you mean by beneficial to some users It does not seem to be very informative