So I will say this right now : I haven’t had a chance to read much on Rudolf. The only books I have read that talk about him are The Reluctant Empress & A Nervous Splendor. Other than that, I’ve read several articles found around the web. The only biography I know that is all about him is Brigitte Hamann’s Kronprinz Rudolf & that book is not available in English.
Now, Rudolf was DEPRESSED. It was severe & he had no support, despite being Crown Prince. (Or because he was crown prince, you pick). His depression stemmed from the fact he had syphilis to the fact that he was forced to basically shut his mouth and do as he was told and go against his beliefs. Family life was not easy what so ever either (his relationship with both parents were in the toilet basically, and the one person who was SO MUCH like him ignored him most of the time. There was also his strained relationship with his wife). Politics also played a hand in his depression. From all sides, he was brought down with no one there to help him up. No one except Mary Vetsera.
But by the time Mary came along, he was already far down. He brought her down with him for God’s sake. But we’re not here to talk about how Rudolf wasn’t an innocent cinnamon roll now are we? (because he wasn’t. people need to stop pretending he was)
Anyway, his depression started when he was young. His father’s strict education plan for him which included more military training than intellectual left the poor boy damaged as fuck. Had Sisi not stepped in when she did, I doubt he would have survived. He flourished under the new tutors for sure! However he was emotionally damaged by that sadistic tutor and with no one to really help him, his emotional disturbances and night terrors just stuck with him and pushed him farther.
Had he had emotional support from Elisabeth at least, things might have been better for him. However, Elisabeth’s lack of support wasn’t the only factor as some might claim. It was a factor, there is no doubt. However, Rudolf’s depression went far deeper than mommy & daddy issues.
& Let’s be real, his parents were first cousins. Incest has consequences.
He had syphilis and had to live with the guilt and shame that he had it.
He had a wife he didn’t really like who he also infected with said disease.
He was a liberal stuck in an ultra-conservative court where his words were ignored by everyone, including his father. (who let’s be honest, should have listened to his son at least). He was a liberal who was forced to keep his mouth shut while he waited for his turn to rule. He, like Elisabeth, was caged in the court. But unlike Elisabeth, he was unable to escape.
Politically, he was at a roadblock with no escape. He was forced to stick to the script even though he wanted to go off and do what he thought would advance the Empire. Instead he was forced to watch silently and SMILE as the Empire went back in time and his father made mistakes.
He was alone with no one to support him. It’s not like he was able to talk about it with the one person who would understand as she was off doing whatever it was she was doing at the time.
Everyone expected him to be like his father, to be able to stand alone as the waves crashed against him and swallowed him. But Rudolf wasn’t his father. He was more like his mother ; he had a heart.
He was a STRANGER in his own family. No one understood him & he KNEW this. His own mother feared him at times because of how he treated Marie Valerie. He was shoved aside and expected to be okay with it.
TL ; DR - Rudolf’s suicide was caused by his severe depression which was caused & exacerbated by a number of factors.