For me, I think it could be a mixture of both. Anxiety and depression run in my family on both sides. I also think my mother has borderline personality disorder. So, needless to say, people related to me are pretty f*cked up. I'm sure that contributed quite a bit.
I also think I inherited (or at least learned) a lot of my mom's negative characteristics. Not her borderlineness, but severe depression, anxiety, low self-esteem, constant worrying and obsessing. Things of that sort. My mom is totally psychotic and paranoid about many things. Whether it be about health, well-being or expired dates on food. She refuses to eat anything that's a day over its expiration date. Logically, I know it will most likely still be fine to eat, but she won't touch it. Over the years of having to put up with that, I've started to wonder and question if certain foods are safe to eat.
Blah blah. Pointless sh*t. Yeah, I think my issues are environmental and genetic. I'm just messed up.