The primary driver to pathological dissociation is attachment disorganization in early life: when that is followed by severe and repeated trauma, then a major disorder of structural dissociation is created (Lyons-Ruth, Dutra, Schuder, & Bianchi, 2006).
Frank M. Corrigan, Neurobiology and Treatment of Traumatic Dissociation: Towards an Embodied Self
attachment, borderline-personality-disorder, childhood-trauma, dissociation, dissociative-disorders, dissociative-identity-disorder, mental-illness, structural-dissociation