Ultimately does it matter why? Who to blame it on? The actions are still the same.
I would say the majority of addicts have underlying mental issues of some sort. While that is terrible, it is a fact. The only thing a person can do is come to terms with it and get help, or they continue to use and be mentally ill. That's the only two choices.
Hugs. Put the focus back on you, and your wants and needs.
XXX