Answer:
dissociative identity disorder
Step-by-step explanation:
Dissociative identity disorder: In psychology, the term "dissociative identity disorder" is also denoted as DID, and also referred to as MPD or multiple personality disorder. It is distinguished as a mental health disorder that is being defined by the maintenance of two different (at least) and enduring personality phases or states. Dissociative identity disorder is being accompanied by "memory gaps".
Causes: Childhood abuse.
In the question above, Monica is suffering from a dissociative identity disorder.