It probably isn't as much about population growth as the increasing wealth gap. My hypothesis would be that a society where people don't feel fair distribution of wealth is more prone to this 'abuse' that you call 'overuse'.
Drug addicts don't become addicts all of the sudden. Lots of people with no place to go resort to awful things, people that feel like they have no place in society do not see a reason to take care of it. It doesn't make it right, but that doesn't mean we shouldn't try to address the root cause.
