When I think about it, I've definitely had issue with depression (or low mood) for years. I just had a great support network back in the US.
Now that Its just me (and my husband) it's not as easy to deal with in a constructive way. There aren't any friends around to simply say, 'Oh, you're having a crap day? Let's grab dinner and chat!' Or pie, a movie... or going on a small adventure.
It's... hard.
And I agree a lot with what kissofdeath said. I simply don't want to share my innermost thoughts with people I don't know well in person and I definitely don't want to burden them with my problems. I think American women are expected to be strong, smiley, happy people who are always kind and gracious and lately.. It's not easy to be that person.
I had to tell my mom the other day on Skype that, 'no, I'm not going to smile simply because you asked me to.'
And if you allow yourself to think about certain things too much, you start to break down. Like crying while you're walking to work. Which is hella awkward.