Yes of course they are. And the addiction is completely due to whether they have an addictive personality or not. I have known some people to drink, use heroin, smoke crack without ever getting addicted and just walk away. There is no drug that is a one time sure addiction for all. Then with others it is a completely different story. It all depends on the person. Most of us have indulged in a number of substances over our lives without problems. Many of those that didn't cope probably aren't around online to even respond. The only reason alchoholics survive longer is due to the legality and lower cost of supporting their habit. But addictive personalities seem susceptible to most substances. The only substance I ever had a long time issue with was tobacco ... not that I found it all that addictive but years ago it was acceptable behaviour which made it easier to continue it. Now the thought of sitting in a room full of smoke is appalling.