If you ask people why they think they are using they will all tell you some reason — depression, anxiety, stress, my parents hated me, etc, etc., but I believe that most of the time they don’t really understand why they are using — the dysfunction of their brain’s reward system caused by the interaction of their genetic predisposition and their exposure to opioid medications. There have been many attempts over the years to find the underlying cause of addiction, presumably because if we figured out what it was we could treat it or prevent it. All of these attempts have been unsuccessful. Treating some one’s stress, depression, anxiety, etc has never been an effective treatment for addiction because it does not address the underlying physiologic abnormality caused by the drugs.
http://www.jointogether.org/news/research/summaries/2010/men-and-women-cite-different.html