Your spouses could very well be wearing masks around you. They can appear happy as clams and when alone, could be "Debbie Downers". If you don't see them very often, then you have no way of knowing just how depressed they are. Depression can take on many forms.
I'm linking a thread that I created many, many years ago that might prove helpful to you:
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.