"The Brave One," Warner Bros. Pictures, released Sept. 14.
The premise: Erica Bain (Jodie Foster), a New York radio show host, is ambushed in Central Park while walking with her fiancé, Dr. David Kirmani (Naveen Andrews), who is beaten to death with a lead pipe. Erica's head is pounded against a concrete wall, and she is thrown into a coma for three weeks. When she awakens, she revisits the incident in a series of flashbacks.
As her body heals, she remains more sensitive to light and sounds and no longer feels safe. Back on the radio, Erica comments that she has turned into "a restless stranger who keeps walking, eating, living." Aside from these feelings of depersonalization, she is riddled with anxiety and fear, and she survives by taking Valium, smoking cigarettes -- and creating a new identity as a vigilante.
The medical questions: Is it realistic for a head trauma victim to emerge from a coma with sensory difficulties? Would he or she be likely to remember the incident? Is post-traumatic stress disorder characterized by dissociation, rage and -- in this case -- the need to create a new personality in the place of the one that is destroyed by the trauma? Can this condition be treated with psychotherapy and medication?
The reality: Head trauma severe enough to induce coma is likely to be accompanied by sensitivity to light and sounds as well as antegrade and retrograde amnesia (before and after the event), so Erica's precise memories of the attack and the events leading up to it are not very realistic.
Foster's portrayal of a severe untreated case of post-traumatic stress disorder is striking but obviously quite exaggerated. "She didn't get the help she needed," the actress has said of her character, as an explanation for why she snapped. Although aggression and even violence can be the result of untreated PTSD, a complete transformation to killer vigilante is very difficult to believe.
At the same time, many of the character's reactions are believable. Rachel Yehuda, professor of psychiatry at Mount Sinai School of Medicine and a pioneer in post-traumatic stress disorder research, says that with PTSD the emotional memory of an unexpected attack is so powerful that the fear response fails to diminish over time.
"Post-traumatic stress," she says, "is a mismatch between what we think the world should be like and what it is really like. We aren't prepared."
The result can be a loss of connection with normal emotions, depersonalization and fracturing of personality, and uncontrollable bouts of rage, such as Erica experiences in the film.
PTSD is a difficult condition to treat, but cognitive therapy (in which a therapist tries to help a victim understand and change how he or she thinks about the trauma) and exposure therapy (decreasing the fear over time by discussing the trauma) can be helpful. Antidepressants (especially selective serotonin reuptake inhibitors, or SSRIs, such as Prozac) have also been shown to be effective in many cases.
Survivors of wars and victims of violent crimes are indeed at risk of becoming violent themselves, especially if untreated. For example, a study published in August in the Journal of the American Medical Assn. found that among Ugandans displaced by war, those suffering from PTSD were more likely to favor violence as the way to resolve a conflict. But whereas violence is quite common among victims of violence, vigilantism is quite rare, especially among women.
Dr. Marc Siegel is an internist and an associate professor of medicine at New York University's School of Medicine. He is also the author of "False Alarm: The Truth About the Epidemic of Fear." In The Unreal World, he explains the medical facts behind the media fiction. He can be reached at email@example.com.