Naruto is mentally stronger than Sasuke, it's a fact.
No, the majority of people would not commit suicide after seeing what Itachi did to Sasuke. Considering that others in the Naruverse have been through worse crap than that. Don't even bother comparing this w/ real life, it's anime. Every single person in the manga has a stronger mental capacity than anyone in real life and "mind-rape" doesn't affect people as much as you think it does. Kakashi even used it on a 12 year old Sakura to present an image of a dying, bleeding, kunai-ridden Sasuke which in turn caused her to faint. They have totally different morals and limits in this fictional story kids.
Sasuke has only had two negative encounters w/ Itachi over the course of 10 years. Don't make it into a bigger deal then it really is fanboys. Sasuke didn't even have close connections w/ the majority of the people in his clan, bar his mother, father, brother, aunt, and uncle considering the fact that he never bothers to mention anyone else and was 8 at the time. The clan was going to die either way and we all know that they refused peace negotiations & Itachi was essentially forced into killing them due to that and to prevent the war that would result & the fact that if the Uchiha attempted the coup, the anbu, root, Hyuuga, Nara, & every other clan in Konoha would come together to demolish them and stop them from overthrowing Hiruzen to gain all of the political power & they would be executed for being traitors. The 2nd time Itachi used Tsukiyomi on Sasuke, he didn't even want to, he actually told Sasuke to not get involved w/ him twice but then Sasuke started screaming that he had to fight Itachi. He kicked Sasuke away the first time that he attempted an attack, but then Sasuke kept on saying that he had to fight Itachi. Kisame was standing right there. What would he think if he saw Itachi being nice to his lil bro? Itachi was a double-agent and had to keep his cover. In this manga, what he did was totally justified due to it being about shinobi and his impossible situation that was forced on him. You cannot compare any Naruto character to the real world, because by real world standards, they have all done immoral things and no situation like Itachi's can exist (13 yr olds are not double agents, clans do not grow stronger through hate or are stupid enough to think they can take on a whole village, etc.)
Examples of people who have worse lives and gotten over it:
1. Gaara-father tries to hire assassins to kill him, father seals demon in him, told that his mother hated him, uncle who was the closest person to him attempted to kill him, hated by village, own siblings fear him, his bijuu threatens him everyday saying that he will kill him and destroy the village if he ever goes to sleep & much much more.
2. Itachi-sees countless people die in the 3rd shinobi world war, parents use him like a tool to get info on Konoha, alot of pressure as a double spy, witnesses best friend die, forced to kill clan (essentially everyone he knows and loves bar Sasuke) when he's a pacifist, has to join criminal organization as a mission, lives entire life being hated even though he saved the shinobi world and Konoha, people view him as a psycho criminal when in reality his clan sealed their own fate, etc
3. Naruto-has a demon in him, people want him dead, has no friends or anyone to talk to for the first 12 years of his life, constantly made fun of and known as the class loser, orphan, doesn't know what love really is and doesn't have close connections w/ anyone until Iruka reaches out to him when he is 12, etc.
I'm really surprised that Gaara, Itachi, and Naruto didn't commit suicide to be honest. Sasuke in comparison to the others doesn't have a reason to.