We really need to stop using the word "habit" in the same context as "addiction" because the two are vastly different. A habit is something like putting your right shoe on first. An addiction typically seems to be the result of a genetic/biological predisposition.
There is an increasing literature on epigenetic influences on the development and maintenance of addictions. Fore example, there are indications that use of nicotine is an epigenetic factor on greater response to other drugs. Much of this literature is in journals outside of the social sciences such as the journal Nature Neuroscience.
Actually, epigenetic modifications can influence every aspect of our body and our life. As you might know, epigenetic modifications alter gene expression with leaving any scar in the genome itself. Various environmental factors including different radiations, nutrients, polutions, and, in my opinion, even brain waves could alter gene expression epigenetically. Also, we know that all human traits and features directly or indirectly relate to our genome and the expression level of genes. Though some of these epigenetic modifications are removed after their stimulating origin is stopped, some of the epigenetic modifications are not erased and are maintained through mitosis and even miosis. Just Google "epigenetic bookmarking" to find a vast amount of information regarding the transfer of epigenetic modifications and tags through generations. Altogether, since all our traits including our habits and addictions are somehow associated with our gene expression patterns, it is clear that epigenetic modification could impact on habit formation or addiction stoppage. I hope I could help.