Final answer:
A prior viral infection or exposure is not considered a causative factor for the development of dissociative identity disorder.
Step-by-step explanation:
The causative etiologic factor that is not believed to contribute to the genesis of dissociative identity disorder (DID) among the options provided is E. Prior viral infection or exposure. Dissociative identity disorder is a complex mental health condition, often linked to a history of trauma or abuse. Factors such as a traumatic life event (A), vulnerability for the disorder (B), environmental factors (C), and absence of external support (D) are considered potential contributors to the development of DID. However, prior viral infection or exposure is not typically associated with the development of this psychological disorder.