What is the name of this movie where a kid cuts his own hand off with a meat cleaver at the dining room table?

I saw a movie when I was a kid that I cannot remember. I was a very dark, kind of warped movie about a family. The only thing I can remember is that the son of this family was suicidal or just liked to get a reaction from family. At one point he chops his hand off with a meat cleaver at the dining room table while his hand is tied to his wrist with string. At another point he is sitting on a chair on the diving board above a pool and falls in to the pool chair and all. I know that part is also from Ferris Beuller but that isnt the movie. Any help would be appreciated.