Multiple personality disorder (MPD) is increasingly recognized as a ch
ronic post-traumatic dissociative disorder. More than 90 percent of MP
D-patients have a childhood history of severe sexual and/or physical a
buse. Pierre Janet's old dissociation theory is essential in understan
ding this disorder and in guiding its treatment. An effective phase or
iented treatment model is described. Its phases are : 1. stabilization
and symptom reduction ; 2. making the diagnosis and sharing the diagn
osis with the patient ; 3. identification of the different alter perso
nalities ; 4. exploration, assimilation and integration of traumatic m
emories; 5. integration of alter personalities; 6. postfusion phase.