There are some depressed but stable speculative neighborhoods out there like North Collinwood and Detroit Shoreway where houses can still be had for $20k in rentable condition but they need to be watched if they go vacant.

Having parents who went through the great depression of 1929, their policy was "if you can't afford to pay cash for something, then you didn't deserve to have it".

It depresses prices and one guy owns 25% of the units renting all to section 8 tenants.

I encounter many women in this position and it's depressing.

I tend to view it as the predictable result of the fed inflating our way out of a depression.

However,  if I go a little further North about 45-50 minutes drive into Orange County, NY, there are a few towns and cities, some somewhat depressed and school districts with bad reputations where I certainly would not move my family to, that have much lower property values, much lower taxes and the numbers work.  

The city I'm in is a depressed area of about 30,000 people with very little in the way of jobs paying over $8.00 an hour, avg household income here is $25,000.

Any tips on how to determine if an area is growing or becoming more depressed?

A higher vacancy rate will start to make itself more evident which equates to a lesser desirability which equates to lower offers and a more depressed market.

While doing all the necessary reading (as suggested by BP) within BP and outside, I come across some negatives by way of doomsayers talking about the 7 year cycles of depression and how we will be impacted in the US come September / October.