Australian doctor Cathy Kezelman has panned the movie, accusing the creators of stigmatising people with Dissociative Identity Disorder (DID), commonly known as multiple personality disorder.
The film, which opened in Australian cinemas today, featured Scottish actor James McAvoy in the role of Kevin, a sadistic Dissociative Identity Disorder sufferer with 23 different personalities, who abducts and terrorises three teenage girls.
Dr Kezelman said the character's portrayal was a "gross generalisation" of the disorder and that sufferers would find it insulting and traumatising.
"Having a film that stereotypes and sensationalises those that struggle with mental illness only adds to the stigma attached with such a disorder," she told SBS.
"It stigmatises people with mental health conditions such as this one, as dangerous.
"Research shows that’s not the case because people with this diagnosis are no more likely to be violent offenders than the rest of the population. So for people to experience it, and see a movie about their diagnosis, is very traumatising."
Dr Kezelman, who is president of trauma support group Blue Knot Foundation, said the disorder stemmed from childhood experiences of repeated abuse and tended to be characterised in several ways, including exhibiting traits such as day dreaming and the formation of separate personalities.
"DIDs is a mental health condition which often occurs as a result of extreme abuse and neglect. It results from perpetrated crimes against innocent children and it creates terrifying conditions for people who experience it," she said.
"It’s very confusing, it’s very chaotic and people struggle to recover.
"The disassociation is actually a protective response which stops the person from being completely overwhelmed when they don't have the resources and support to cope. It's not about human weakness or a predisposition.
"There's a whole spectrum of kinds of dissociation, which can start from normal day-dreaming and inattention, to separate personalities, which are different fragments of a person which haven't integrated."
Dr Kezelman said research suggested that between one per cent and three per cent of the world's population suffer from the disorder.
She pointed to the soon-to-be published research paper, Mental Illness and Violent Behavior: The Role of Dissociation, which found that out of 173 people treated for the disorder, only three per cent reported having been charged with an offence in the past six months.
The Blue Knot Foundation supports more than five million Australian adults who are survivors of childhood trauma.
