As a EMS provider I can certainly tell you it can most definitely can be a gateway drug. Ive spoken to too many parents that have said that their childs addiction to (insert drug here) all started with marijuana. The younger population has no idea that marijuana, while "safe", can lead you seeking other forms of getting high and chasing that next high comes at a very steep price. Ive had to give narcan to the same people that were once only smoking pot. As far as addiction is concerned, personally Im on the fence. A person can be addicted to just about anything. Ive had to transport quite a few patients that told me of the odd addictions they had to seemingly harmless things. I'd imagine marijuana wouldnt be that much different.