What causes it? The ineffective use of debt. Use of debt for intangible goods is probably the biggest culprit. Houses are a perfect example of an intangible good. The house itself has tangible value but the land is extremely hard to quantify. People who buy expensive houses in high priced locations - be very very careful !! Do so only if you can afford to pay off your debt appropriately.
Solutions? We need a serious change in the culture of spending. Debt must be used extremely carefully for only proven or at least very likely to be productive activities. Simplify your life. Instead of buying a house or buying a new car using debt, use the money to start a business, get an education or just be productive. Buy using cash you have or know that you will have.
This issue is pervasive and is highly co-dependent. I.e. Another person's debt is held together by many, many others. More than ever, each of us needs to help each other, encourage each other to be productive and reduce our dependency on debt. Let us hope that we do so sufficiently to avoid the landslide!