One of his friends had already been quoted talking about their conversation shortly before the suicide and his despair regarding another season ending injury. I think it is a realistic perspective to think that played a part in his mental state before killing himself.
Even in college Rondale was taking a lot of hits and the injuries have been piling up in the NFL as well. I think that took its final toll from him and he was unable to overcome. He was fun to watch, sad to see this happen.