I have just watched James Fox being interviewed and he has exploded the myth that Performance led to his leaving the film business. He thought it was a great part, an enjoyable experience and thought it may have led to a real boost to his career. However he chose to follow a religious path for a time. It was a choice not a breakdown.
shareI read an interview with him, and he said it was a breakdown. But it wasn't because of "Performance". It was a combination of a bad DMT trip, his fathers death, and other factors. I don't know if it was a full-on nervous breakdown, but it was enough to make him want to get away and sort of start over. I don't think his mental health was too bad during the making of the film, as he was the one person who actually ACTED in the movie. I'm not saying Jagger and the girls were bad, they did what was asked, acted stoned (because they were) and spouted a bunch of nonsense.
Unfortunately, by all accounts I've read, little Michele Breton was the one who had the breakdown. According to Anita Pallenberg and Keith Richards she was constantly freaking out and had to be shot up with Valium prior to almost every scene. And her life apparently went downhill after that because according to Anita, Michele has been in and out of mental institutions over the years.
Although apparently that didn't happen until at least after 1971, according to the book "Exile On Main St: A Season In Hell With The Rolling Stones" she was hanging out in the south of France during the Exile sessions.
"IF THE DEVIL HAD A NAME, IT WOULD BE CHUCK FINLEY!!"