A series of thoughts or actions which feeds back into itself, causing a situation to become progressively worse. It is worse than a vicious circle, which is self-sustaining in its current state
spatially or metaphorically from a higher to a lower level or position; "don't fall down"; "rode the lift up and skied down"; "prices plunged downward"
If you refer to a downward trend, you mean that something is decreasing or that a situation is getting worse. The downward trend in home ownership is likely to continue. upward