Maybe have a 'mood' last for two seasons.. and for half a season its 'fresh' second half a season its strong.. first half of second season its neutral.. then the last bit its vague.
with a simple point modifyer on it.. 1 for vague, 2 for neutral, 3 for strong, 4 for fresh..
and maybe add a third 'mood' determination.. for whatever reason, but it could keep them steadfast through the harsh times.. but break down in the calm times.. (like alot of people real life) these are pioneers! steadfast and hardy!
it might be a randomly generated thing to add to it, some being more steadfast than others.
more reactions to moods would serve well certainly.. not just going insane and dying or trying to kill your friends
something as benign as taking two to five times as long to complete something... sleeping twice as often..disrupting other dwarves (grouching at them to give them a bad thought) or the oposite too.. working a quarter to twice as fast.. sleeping half as much.. complimenting other dwarves giving them good thoughts..
and some 'thoughts' should have more weight than other thoughts.. watching their friend get slaughtered by a fireman right infront of you should be atleast three times as bad as sleeping on the ground
there's also room for qualifiers in there.. if your mobilized for war.. seeing someone die would be far less of an impact.. if your just arriving.. sleeping on the floor wouldnt bother you much.. if everyone is thirsty it would be doubly worse.. an accumulative.. not just "i couldnt find any water" but.. "were all dying of thirst!"
could be a very dynamic and interesting system... and still room for those extremes.. say everyone was standing around the well partying as the fireman came up and torched your leader.. that.. would be a cause for bezerk mode