Maybe the definition of depression is different, society to society. I'm certain a good amount of earth's human population has at one point in the course of their lives felt hopelessness, for whatever amount of time.

The majority of those with access to TV who've also seen some American media have likely felt they're missing out on the riches and opportunities that can be had that they're not fortunate to.

Is the definition of mental illness and depression and their treatments and factors the same across cultures?

To me it seems (opinion) that the only constant is... if you feel sad: there's a pill for that.

People in bad situations work hard to get themselves out. It's human pride, it's our nature. People don't just kill themselves. Are those who do "weaker beings" or have bigger struggles than those who haven't?

There's another factor at play here, in my opinion, and it's the medication.