ONE WOULD think that an orthopedic surgeon, a person the public expects to be calm and competent at all times, would be the last one to claim that on a couple of days a month, for reasons beyond her control, she is likely to become so aggressive that she drives erratically, becomes verbally abusive, kicks over tables and assaults police officers. Dr. Geraldine Richter, who used such an argument in a Fairfax court this week, may be having second thoughts about the wisdom of claiming that premenstrual syndrome, not alcohol, was the cause of her outrageous behavior last Thanksgiving night, when she was arrested on the Dulles Toll Road and charged with a misdemeanor drunk driving offense. She may have avoided a conviction, but at what cost to her hard-won professional standing?

Remember Edgar Berman, a physician and political sidekick of Hubert Humphrey's? He stirred up a hornet's nest in 1970, when he claimed that women were unfit for national leadership because of their vulnerability to "the raging hormonal imbalance of the periodic lunar cycle." Citing, for example, the preferability of male over female leadership during the Bay of Pigs crisis -- could it have turned out any worse if Madonna or Rosanne Barr had been in the White House? -- Dr. Berman made a career of putting women down as physiologically inferior. But his assault mobilized others who argued persuasively that it is preposterous to believe that every month half the human race is emotionally unbalanced and not to be trusted with serious responsibility. Realizing that accepting this theory would greatly disadvantage women in employment and other situations involving bias, feminists also fought the inclusion of PMS in the psychiatric manual of recognized disorders.

Even assuming that 5 percent of all women have unusually severe premenstrual headaches, cramps and the like, is this condition a defense to crime? At least twice, English courts have found PMS to be a mitigating factor in cases involving violence, but Americans have been more skeptical. When the defense was raised in a child abuse case in New York, prosecutor Elizabeth Holtzman countered that while "PMS can be an uncomfortable condition, {after extensive research} we found no evidence that it or any other special female physiological reactions to menstruation make women lose control over their actions . . . never mind turning them into some kind of raging beasts." Until the scientific case has been made that PMS is an excuse for more than skipping a gym class, it remains on very shaky grounds as a legal defense.