TORONTO - It's long been a fixture of the late-night sci-fi movie: a seemingly normal person is suddenly gripped with the unshakable belief that close friends or relatives have been mysteriously replaced with identical-looking doubles.
Spectators in an eastern Ontario courtroom, however, have witnessed first-hand this week the tragic consequences of a rare, real-life mental disorder that manifests itself in a very similar delusion.
Actor and comedian Tony Rosato - a fixture of Canadian television in the 1980s, best known for his turns on "SCTV" and "Saturday Night Live" - has been held without bail for more than two years on a charge of allegedly harassing his estranged 30-year-old wife, Leah.
Rosato has been diagnosed with Capgras's syndrome, also known as the Capgras delusion - a condition that results in the unshakable belief that an acquaintance, most often a close relative, has been replaced by a substitute.
The condition is extremely rare, said Dr. Joel Jeffries, a psychiatrist at the Centre for Addiction and Mental Health in Toronto, who's only ever seen it manifested in a handful of patients.
"It's so dramatic when it occurs that people pay a lot of attention it, even though it's very unusual," Jeffries said.
The delusion is often associated with schizophrenia, bipolar disorder and delusional disorder, though it's also seen in patients diagnosed with Alzheimer's disease, multiple sclerosis and epilepsy, Jeffries said.
It's named for French psychiatrist Joseph Capgras, who co-authored a 1923 paper about a woman who complained various "doubles" had taken the place of people she knew.
Daniel Brodsky, Rosato's lawyer, has said his client has been diagnosed with the condition. A psychiatrist is expected to take the stand next week at Rosato's trial in Kingston, Ont., three hours east of Toronto.
It's a story reminiscent of movies like "The Stepford Wives," in which a woman suspects her once-independent friends have been replaced with mindless robots, or "Invasion of the Body Snatchers," where hysterical residents claim loved ones are being replaced by impostors.
There's nothing fictional or fantastic about Rosato's story, however.
Rosato and wife Leah were married in 2003, just four months after they first met in a Toronto coffee shop. She continued to live in Kingston, while Rosato lived in Toronto with his mother and visited his wife most weekends.
About nine months later, the couple moved into a Toronto apartment and Leah Rosato gave birth to a daughter. She left the apartment in January 2005 with the girl and returned to Kingston - precisely why isn't clear.
Two months later, Rosato began telling police his wife and daughter had gone missing and were replaced by impostors. He has steadfastly insisted there's nothing wrong with him.
People identify one another in various ways - through appearance, voice, mannerisms and the way they relate to others. When those characteristics change, a healthy person can conclude it's not because the person has been replaced by a doppelganger, Jeffries said.
"What happens (with Capgras) is that that capacity gets impaired, though we don't know how," he said.
People diagnosed with the delusion are usually more annoyed than angered by the perceived change, he added.
"They'll usually ask, 'Why are you doing this?' or 'What happened to the real people?"' Jeffries said. "There's often annoyance, more than alarm."
A psychiatrist in the United States wrote about one Capgras patient who thought his poodle had been replaced by an identical but different dog. Another study cited a patient who, every morning, believed that his running shoes had been replaced by identical substitutes during the night.
Jeffries said patients usually respond to treatment with anti-psychotic medication. He said he wasn't aware of a case where, with appropriate treatment, a patient was unable to shake the delusion.
"I'm sure it happens, but it's relatively rare that the belief becomes intractable."
