Social class most definitely has something to do with it. Those in lower social standing have less access to help, healthcare and methods to increase their situation (be that career options, education, whathaveyou). If you ask anyone who is a professional in the field and knows their population statistics they will tell you that things can be hard, but they're doubly so for individuals in poverty.
I grew up middle class, but I didn't get a lot of the advantages because of my particular trauma cause (my family)-which generally means no extras of any sort and I recently came to the realization that my mother pretty much farmed me for tax breaks and family allowance.
I was still privileged in that I had no food or clothing or shelter insecurities, but going to school while kids made fun of your clothes and you couldn't stomach your lunch, never mind later life with no transportation in the country (isolation), and lack of access to funds for post secondary (though she did take my tax credits for my first year-and informed me after the fact), that was rough.
I still wasn't *really* poor. So I avoided the wondering about if I was going to get supper, or if I could make my clothing last another couple of days, and whether I'd still have a roof over my head. Those things can do a number on a child growing up. The insecurity of not knowing where your next meal is, where you're going to live, etc is enough to cause a kind of childhood trauma all it's own.
My heart goes out to those who had to grapple with it. Life is hard enough as it is.