There's not just the Uchihas. Most of the characters have some kind of mental ''instability'', be a slightly sociopathy or right-down psychopathy and shit...
It's sort of a ''must have'' in that kind of environment.
I'd say Gaara's obsession with Naruto is also borderline unhealthy.
OT: Of course. We have Sakumo Hatake who stopped caring about being a shinobi and killed himself after his whole village shunned him. We have Itachi who was most likely suffering from some level of deprerssion after having killed his entire family and being in that whole Uchiha-or-Konoha debacle. We have Gaara who was emotionally scarred from childhood for both the villagers contempt of him and all of the assassination attempts, directed by his own father no less. We have Kakashi who like Itachi also had some level of depression after "killing" Rin, seeing his father commit suicide, and seeing both Obito and Minato die. Orochimaru was mentally scarred from the death of his parents as a child and look how that affected him. Tsunade with haemophobia due to the death of Dan and Nawaki. Don't even get me started on Kakuzu, Hidan, and Sasori... There are many examples.