I am at work but just had a thought about Sanity rules for Cthulhu and wanted to start putting ideas down so I don't forget. It's not solid enough to make a thread about.
Madness Tracks -
When an investigator first goes nuts, they and the keeper pick the madness or roll out a random one. But they also pick a track or theme for the investigator. Each time the investigator picks up new SAN losses they move along their track to stronger insanities and more obvious outbursts.