“I won’t spoil the movie, but all four of the main characters try to get better and recover, to no avail.”

You’re not spoiling the movie because that does not happen. No one even mentions recovery. “Getting better” means getting high again. The characters in the film make one terrible decision after another in pursuit of the high.

Tyrone and Harry are part time street level heroin dealers and junkies. Marion is some spoiled rich kid whose parents have written her off because she’s a dope fiend. Mrs. Golfarb is wasting the rest of her life watching infomercials on television. You keep waiting for them to do the right thing, and they don’t. In that way it is very true to life, and a brilliant film.