Is Heroin Addiction an Obsession?

Lately I've been thinking about addiction nonstop...It's become somewhat of an addiction to think so much about addiction. Why do some people become addicted to heroin and some don't? Why do some people become addicted to cigarettes and some don't? In a nutshell, there are many theories but no one really knows what causes it.

I've noticed in dealing with my own daughter's heroin addiction... [she's been taking seboxone and is still doing very well by the way] I think that addiction whether its an addiction to drugs, eating, or even to blogging...they're all dependencies, obsessions, habits, or cravings. The addict uses the addiction to self-medicate for a deficiency in the brain. Is this true? Could this be genetics? Using seboxone does reduce the cravings...counseling helps tremendously...however, I still notice the obsessions, habits, and dependencies if you will, are still intact. Once a person is clean...should they be redirected towards a new obession a new addiction? An obession that is harmless but yet still satisfies the brains need? What would that be? Will it be enough to prevent the brain from taking her right back to heroin, and to addiction?