No, not at all. We needed a place with a completely Earth-like environment, for various reasons, but we haven't insulted ourselves. People can go outsides freely. There are no hallucinations being reported now.
Depression, huh? Any connection, you suppose, with-
Say, why are you so interested in all this?
When people are outside the dome that's when they see hallucination
Sam is going outside and that is where he will see the hallucinations
Sam is starting to see smoke and this effects what he will do next and the events leading up to how to cure the Commander
Sam thinks he is starting to see a cow in the smoke this creates the main conflict of the hallucinations