The Jean Harris murder trial has had everything: sex, wealth, a love triangle, a best-seller, even quick weight loss.

And now, to the nation's most popular ongoing soap opera is added another dimension: drugs.

Their presence in this affair had been suspected for some time. As far back as the jury selection the defense attorney had tantalizingly questioned prospective jurors about the use of "controlled substances," prompting a did-she-or-didn't-she discussion about the former Maderia School headmistress. But it was not until this morning, as the trial moved into its eighth day, that drugs were specifically mentioned in dramatic and startling testimony.

It came with the account of star prosecution witness Suzanne Van der Vreken, on the stand for her sixth and final day. Van der Vreken, housekeeper for Dr. Herman Tarnower, the man Harris is accused of murdering, had been in the Tarnower home at the time of the shooting. She had heard shouting and gunshots. Today, under cross-examination from defense attorney Joel Aurnou, she was asked to describe Harris' mood on the night Tarnower was killed. Her answer was far from what the students at the Madeira School might have suspected about the woman they once nicknamed "Integrity Jean." There was also a hint of behavior on the doctor's part that might have surprised his patients.

"The night of March 10, did Mrs. Harris appear to be herself to you?" began Aurnou. Then, after an objection from the prosecution, he tried again. "When you looked at Mrs. Harris at the scene on March 10th did you notice something unusual or different about her demeanor or appearance?"

The Belgian-born housekeeper answered carefully, in her heavy French accent: "I don't know if this is the right word -- she seemed -- very high," she said.

"And you also told the police at the time it did not appear she had been drinking?" Aurnou pressed.

Van der Vreken, who has been markedly hostile to Harris, admitted this was true.

"And do you know whether Harris had been taking sleeping pills or other medication?" continued Aurnou.

There was an objection from the prosecution, upheld by the judge, but not before the jury heard the answer.

"Yes," said Van der Vreken.

"Had you observed Mrs. Harris taking sleeping pills?" said Aurnou, undaunted.

"She told me," said Van der Vreken.

"Had you observed Mrs. Harris taking any other pills?" asked Aurnow.

"Yes," said Van der Vreken.

"And do you know the source of those pills?" Aurnou went on.

An objection from the prosecution prohibited the housekeeper from answering.

The headmistress of Madeira from 1977 until 1979, Harris has been accused of second-degree murder in the death of Tarnower, her lover of 14 years, in the bedroom of his home in Harrison, N.Y. The prosecution, noting that the 69-year-old cardiologist had been seeing a younger woman -- Lynne Tryforos, 37 -- has maintained that Harris shot Tarnower in a jealous rage. The defense has claimed the shooting was a "tragic accident," a suicide attempt gone awry. Defense attorneys have insisted that the events leading to the shooting grew out of Harris' professional life in McLean, and that she was "suicidally depressed."

Today's testimony about pills, elicited by the defense, would seem to support its position that Harris was disturbed, although the portrait bears little resemblance to the woman Madeira parents and students knew. In her last year at Madeira, so strict was Jean Harris that she once suspended seven girls who had gone drinking in a Georgetown bar, though the offending act, in that case, reportedly consisted of one beer per girl. She had also expelled four girls after marijuana was found in their rooms.

The testimony today, much of it charged and mysterious, was not, however, limited to drugs. It dealt with Harris' anger at Tarnower, with their relationship and -- in a veiled way -- with the subject of who had slashed Harris' clothing. This was an act, brought out in testimony Wednesday, presumed to have been perpetrated by the Other Woman.

Under direct examination from Assistant District Attorney George Bolen, housekeeper Van der Vreken helped buoy the prosecution's position that Tarnower's affection for Jean Harris, in past years, had indeed been fading. Referring to her housekeeping journals, the much-vaunted "love diaries of the swinging doctor," Van der Vreken testified that Harris had stayed at the doctor's home 63 times in 1977, 49 times in 1978 and only 26 times in 1979. It was sad testimony to a fading affair -- a scorecard, one could say, if one wanted to be cruel.

Listening to it, Harris -- who of late has been pale and at times listless -- was visibly pained. Later her attorney tried to undermine the testimony by eliciting from Van der Vreken the information that Van der Vreken had not kept track of the many vacations Harris and taken with the doctor -- the Thanksgivings in the Caribbean, the New Years' Days in Palm Beach -- but the prosecution's point had been made.

Less pointed but much more curious was another line of questioning by the prosecution. Previously, Van der Vreken had testified that while Harris and the doctor were on a vacation, Harris had come home to find some of her clothing slashed and torn, and that the person who came to the house that weekend was none other than the Other Woman, the blond and beautiful Tryforos.

But when Bolen questioned Van der Vreken, a bizarre alternative was suggested.

He asked when the housekeeper had last seen the contents of the clothes closets. A few days before Harris and Tarnower had gone on vacation, she replied. He asked how the housekeeper had learned that the clothes had been slashed. She said Mrs. Harris had told her. Finally, Bolen asked the housekeeper if it were true that all of the slashed clothing was Mrs. Harris'.

"You made mention of a jacket that had been torn and slashed. Whose jacket was that?"

The housekeeper's answer, making the unspoken accusation as it did that Mrs. Harris, in an attempt to gain sympathy, might have destroyed her own clothing, shocked and confused the courtroom.

"It was Mrs. Tryforos,'" said the housekeeper.