Pehaps teaching about money math or investing or comparitive value maybe even possibility multiplives. Perhaps they can read to thier child, if they can't, there are many books on tape that they can listen to together on new and interesting things. Children see what their parents do and imitate it. If the parent cares, so will the child. If the parent does not care, so will the child not care.
Depression is a wide spread ailment among the working or poor.