Existential depression happens when we get disconnected from our spiritual side, and our true purpose in life, and from God (sorry, I said the 'G' word...)
When life is framed in term of material achievement, then it can be precisely when we achieve that materialistic pinnacle of success that we suddenly realize that it's not all it's cracked up to be, and it didn't really solve our problems.
That's why so many of the materially 'successful' people in life commit suicide, go mad, or retreat into substance abuse (sometimes covertly, other times in a very obvious way.)
They won the lottery - and it still didn't take away that gnawing feeling that life is empty and meaningless.
So what does?
The following things:
- Having a good answer to the question: what's the true purpose of being alive
- Being in touch with, and developing your 'real' self, i.e., your spiritual self, or soul (btw, this is NOT the same thing as being 'religious', as it's possible to be superficially religious and still disconnected internally from your true, higher self and God.)
- Making an effort to grow, change, develop and improve in some area, however small, every single day of your life.
- Cultivating gratitude - when people take all the good and blessings in their life for granted, it can deaden their joie de vivre and appreciation for being alive faster than anything else. By contrast, when we start trying to really appreciate things in life, even the small things like a hot shower, or good cup of coffee, or hug from someone that loves us, it transforms us.
- Searching for the messages God is hiding in every single thing that happens to us, or that we experience. Again, when someone believes that life is just a set of random coincidences, it all starts to seem very meaningless and even cruel - especially when we're going through a bad patch.
By contrast, when we make an effort to decode the hints that God is sending us via all the different facets of our interactions and experiences, absolutely everything in life becomes meaningful, because we know it's a tailor-made message from God, about something we need to work on, change or fix.
When people live with the reality that this world is just a temporary corridor, and that the real successes and achievements are the internal ones - like overcoming things like our anger, jealousy, ingratitude and hatred (OK, I have many more things to work on, on my own list, but hey, I have to keep some of my dignity...) - THEN the existential depression finally disappears, even if the 'externals' are not so good, or even downright bad.