When top London psychotherapist Frank Tallis was consulted by a stalker suffering from an extreme case of unrequited love, he was struck by how balanced the woman seemed in other aspects of her life.
The 40-something worked as a lawyer’s clerk and was happily married, but had fallen head-over-heels for her dentist, who’d exhibited a nice bedside manner after a particularly nasty surgery.
Her feelings weren’t reciprocated in the slightest and the dentist fled the country to get away from his psychotic patient.
“Pathological love is much stronger than ordinary love,” Tallis tells The Post. “Megan’s experience [all patient names have been changed] demonstrates how we can feel mentally safe and secure when we are, in fact, walking on a precipice and can tumble over at any time.
“The line between normality and abnormality is blurred by love.”
It’s a theme that anchors Tallis’ upcoming book, “The Incurable Romantic: And Other Tales of Madness and Desire” (Basic Books, out Tuesday). Part memoir, part scientific exploration, the collection chronicles more than a dozen tales of love gone horribly wrong.
As Tallis explains, there is a spectrum of love-fueled insanity — ranging from a patient who developed a narcissistic yearning for his own body, preferring masturbation to his own partner, to an elderly widow who suffered from hallucinations because she missed the rampant sex she enjoyed with her husband, with whom she had nothing else in common.
Now retired, he has drawn on his 20-year experience as a clinical psychologist to write the remarkable work of nonfiction. After researching his 2004 book “Love Sick,” Tallis found himself increasingly drawn to the darker corners of the amorous mind.
Megan, the jilted stalker, is one of his more bizarre cases. She suffered from the rare de Clérambault’s syndrome — named for the French psychiatrist who first detailed the diagnosis in 1921 and classified less lyrically in modern psychology as “Delusional Disorder: Erotomanic Type.”
“It is effectively a delusion of love,” says Tallis. “The individual is usually a woman who falls for a higher-status man who has given no indication of interest whatsoever.
“She believes that the passion is reciprocated and, even if the target is avoidant, it’s because they are overwhelmed or frightened [by what she perceives is the truth]. The syndrome patient usually tries to persuade them that they are in some kind of spiritual union.”