Matthew Perry said in interviews he was heavily addicted to drugs through much of the series to the point that he has no memories of filming season 3 and 4. He says he can't recall several years of his life thanks to his addiction. Apparently it has left him with lifelong health conditions.

He was the one who played Chandler which has Q mentioned "Chandler" is a comm for "Child Handler". I don't know that Perry himself had anything to do with that, but he played a character they used for comms about it. In one season he dresses up as a giant pink bunny. DS bunny comms are disturbing.

Matthew Perry said in interviews he was heavily addicted to drugs through much of the series to the point that he has no memories of filming season 3 and 4. He says he can't recall several years of his life thanks to his addiction. Apparently it has left him with lifelong health conditions.