| Dr. |
Heimer | Doctor attacked by Elizabeth |
| Mrs. |
Jasberson | Elizabeth's next-door neighbor |
| Immanuel |
Kant | German philosopher known for his work in ethics and metaphysics |
| Dr. |
Larson | Elizabeth's primary doctor |
| Dr. |
Phil | American TV personality and psychologist |
| Bob |
Rooth | The twins' adoptive father |
| Dalila |
Rooth | The twins' adoptive mother |
| Elizabeth |
Rooth | Protagonist and narrator. Aka: Bethy |
| Emily |
Rooth | Elizabeth's twin sister |
| Diana |
Ross | American singer and actress |
| Taylor |
Swift | American singer-songwriter and global pop artist |
| Mark |
Underwood | Clinical psychologist |
| Annabelle |
| Elizabeth's favorite doll |
| Archeus |
| Rick's imaginary enemy |
| Arlene |
| Patient diagnosed with bipolar disorder |
| Chrissy |
| Emily's enemy |
| Denise |
| One of the patients |
| Doris |
| One of the patients |
| Felicia |
| Elizabeth's roommate |
| James |
| Elizabeth's substitute babysitter |
| Jeremy |
| Friend of the twins' adoptive mother |
| Lisa |
| Therapist of the twins |
| Marc |
| Elizabeth's new boyfriend |
| Matt |
| Patient unaffected by his surroundings |
| Polly |
| Elizabeth's nurse |
| Rick |
| Patient diagnosed with schizophrenia |
| Rose |
| Co-patient; suffers from anorexia |
| Shelly |
| Patient diagnosed with depression |
| Teresa |
| Gym instructor |
| Thomas |
| Elizabeth's boyfriend |
| Tobi |
| One of the patients |
