The impermanence thing is probably easier to see for any thoughtful observer (although it's also easy to forget). The insubstantial thing may seem a little strange at first. The Buddha taught that all things--including us--are without self, i.e. that they are dependent on conditions and come into being and pass away as conditions change.
As the Buddha was reported to have said,
If this is, that comes to be;
From the arising of this, that arises;
If this is not, that does not come to be;
From the stopping of this, that is stopped.
That can be a good thing to keep in mind when confronted with problems or even with a sudden turn of good fortune. Whatever it is, it won't last forever and only exists now due to an temporary constellation of factors.
It can also be a useful insight to those interested in either changing things that need to be changed or preserving things that need to be preserved. What is possible at any given times depends on external conditions and how we respond to them. And the conditions change from moment to moment.
DEPRESSION? Maybe not (but maybe).
SPEAKING OF DEPRESSION, lots of Americans are dealing with their own.
SPEAKING OF BOTH KINDS OF DEPRESSION, here's one that brings up some old school sociology.
GOAT ROPE ADVISORY LEVEL: ELEVATED