The 1980 DSM had characterised the illness as «extremely rare» and possibly caused by child abuse The new one described it as «not nearly so rare as it has commonly been thought to be,» and caused «in nearly all cases» by child abuse, often sexual. […]
It became common for MPD sufferers to possess scores, even hundreds, of alters (one was reputed to have 4,500). Not all were human. Some weren’t even alive. Patients reported gorillas and lobsters, as well as unicorns, angels, and—if the alters were immobile and voiceless-trees. Supernatural-sounding claims sprang up. A person with MPD, it was said, could have one alter with blue eyes and another with brown eyes. Such a person could be diabetic but have a personality whose insulin levels were normal. Even blood types could change.
NATHAN, D. (2012). Sybil Exposed. Nueva York: Free Press
Bonus: la cacatúa loca y yo, leyendo.