On Dec. 16, 1980 a 36-year-old Englishwoman named Christine English ended a love affair in the most conclusive way possible: She ran down her boyfriend and killed him. Last November she pleaded guilty to manslaughter, but was discharged from custody and was deprived of her driver’s license for only a year. The decision was electrifying, but not without precedent. The day before, Sandie Smith, 29, an East London barmaid, had been placed on probation for carrying a knife and threatening to kill a policeman, though she was already on probation for stabbing another barmaid to death. The reason for leniency: Smith, like English, was ruled to be in the grip of a biological force beyond her control—a compulsion to violence triggered by premenstrual tension.

Smith, in fact, has a bizarre criminal history, including nearly 30 convictions for offenses such as arson and assault and a record of breaking people’s windows with stones. She has tried to take her own life 18 times. Following the stabbing of the barmaid, she told police she could recall nothing of what had happened, and was imprisoned for 10 months awaiting trial. Then her father, a night watchman, came forward with his daughter’s diary. After reading it, he had come to the conclusion that her outbursts of erratic behavior always occurred at monthly intervals, just before her menstrual period. He had read in a newspaper about an extensive study of premenstrual tension and wondered if Sandie could be suffering from PMT.

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Dr. Katharina Dalton, the London gynecological endocrinologist who authored the paper, has been researching the syndrome since 1948. She examined Sandie, and on the basis of her case history confirmed the father’s suspicions. Smith was treated for three months with the hormone progesterone, which Dr. Dalton maintains corrects a behavior-altering chemical imbalance, then was released on condition that she live with her parents and receive daily injections. When she threatened the policeman a year later, her dosage had been reduced in an effort to determine how much she required. As a result, her lawyer argued successfully, she had been transformed once more into a “raging animal.”

Although premenstrual tension was not introduced as a defense in the Smith and English cases, the British courts’ acceptance of PMT as a mitigating circumstance in determining sentencing has been both hailed and condemned. The rulings have been deplored by feminists, questioned by medical authorities, and greeted ambivalently by lawyers who might welcome PMT as a useful court room tactic, but who fear it may come to be regarded as an excuse for any kind of violence by women. Even Dr. Dalton seems concerned by the prospect. “Lawyers are sending more and more cases to me,” she says. “It’s a great worry because I get plenty of rubbish. The courts will accept PMT if it’s the genuine article, but doctors have to be more careful about the diagnosis.”

Dr. Dalton’s critics, however, doubt that PMT is all that she says it is. “I am appalled by the judgments in the Smith and English cases,” says hormonal researcher Lynda Birke. “They imply that women are victims of their biology and are in a position of diminished responsibility.” She maintains that Dr. Dalton’s work is important “in that it underlines that some women suffer from something that is not purely imaginary,” but Birke doesn’t agree that the problem has a hormonal basis. “Progesterone helps some women,” she says, “but so do placebos and vitamin B-6.” Another skeptic, Dr. David Benton, a lecturer in psychology at University College of Swansea in Wales, believes there is insufficient evidence to support Dr. Dalton’s PMT theory. “In the history of psychiatry, there are all sorts of treatments that will have an effect if the people administering them are plausible,” he says. “But there is no simple biological reason for behavior. Any disorder has a psychosomatic element.”

Such arguments are unconvincing to Dr. Dalton, who began treating herself with progesterone some 30 years ago after she was troubled with monthly premenstrual migraines. Previously she had noticed that the headaches disappeared only during pregnancy (she has four grown children), when a woman’s body produces up to 30 times more natural progesterone than normal. Other indicators of the premenstrual syndrome, she says, include asthma, epilepsy, depression and compulsive overeating. She suspects that many female child abusers may suffer from PMT and believes that gynecologists and general practitioners should be testing more frequently for the syndrome. As many as 40 percent of all women suffer from progesterone insufficiency to one degree or another, she says, though many of them may not be aware of it. As for the criticism she has received from feminists, she says, “I’m not worried about women’s groups. I’m making better women of the few who are letting down our side.”