wild-caught snake

[adamanteus]

Snakes can display "depressed" behaviour, whether or not this is depression in the usual (human) sense, I rather doubt. Illness and stress brought on by environmental issues can cause depressed behaviour. A larger viv might help in deed. I would certainly make sure the enclosure is well furnished with ample hiding opportunities. The snake must feel secure. You might also want to check all the other environmental factors (temperature etc). Good luck.