First, the basics:
- Every dwarf needs their own bedroom (dormitories don't cut it)
- Make some rock mugs or metal goblets (they get annoyed drinking out of the barrel)
- If you have a BUNCH of outside plant gathering, hauling or hunting, a lot of them hate getting rained on -- the sun's too bright, it makes them puke etc.
Got those bases covered? Then we move on to two
extremely helpful things, one easy and one hard:
1.
Temples - at the very least, a single "no deity specified" temple can go a long way in staving off depression.
2.
Mist generator (or waterfall) - this is the closest thing I've ever seen to dwarven antidepressants. Those filthy little bastards LOVE them some mist! Here's a guide:
https://dwarffortresswiki.org/index.php/MistIn the olden days (v. 47.xx), I used to dig a channel from a brook or river into my fort, let it plummet beside (or right through the middle of) the main staircase, then a couple levels below that, dig a drainage tunnel to the edge of the map. For some reason, water + fortifications + edge of map = infinite drainage. I'm NOT sure that'll work in v. 50.xx -- I've seen people use entire cavern levels for drainage...
Couple other things:
3. Once you have that main non-denominational temple, you're VERY likely going to need temples for each specific deity your crew prays to.
4. Do you have a
tavern? If YES, do you have
performers in the tavern? A dancer, singer and musician + instrument = lots of good thoughts. I've never used bartenders in my taverns, though -- read too many horror stories of death by alcohol poisoning (apparently, possible even for dwarfs!)
5. MAYBE your dwarfs are overworked? I picked up this tip from Kruggsmash -- once a year, for like 4-5 weeks, turn off ALL labors and restrict everyone to the bedrooms/meeting areas/tavern/dining room levels. It forces them to take it easy, socialize, pray, just generally chillax.