The Army has acknowledged that it dosed a black former private first class with LSD without his knowledge in the course of a three-month interrogation in which he was also denied food, sleep and bathroom facilities, given injections of so-called truth serum and questioned remorselessly in an attempt to make him confess to stealing classified documents.

James R. Thornwell, now 40 and jobless, says that the 16 years that lapsed he was thus interrogated since near Orleans. France, has been marked by nightmares, headaches and recurrent depression.

The Army in releasing documents associated with the ease to Thornwell's lawyer under a Freedom of information request, in which an American national was given the potent hallucinogenic drug as part of a criminal; investigation.

The documents indicate that sixteen foreign nationals also received the drug under two programs. "Third Chance" and "Derby Hat," which were designed to test the efficiecny of LSD in interrogations.

Thornwell's attorney, Harvey M. Kletz of Berkeley, immediately asked Rep. Ronald V. Dellums (D-Calif.) to introduce a private bill that would compensate Thornwell as the government compensated the family of Dr. Frank R. Olson, an Army scientist who apparently committed suicide in 1953 after being given LSD without his consent. The family received $750,000 and President Ford apologized to Olson's widow and three children.

"They dealt this way with a white, middle-class scientist," said Kletz. "Why shouldn't they deal the same way with a black PFC whose life has been destroyed."

Kletz said he also is seeking reversal of a decision by the Veterans Administration, which twice refused to grant Thornwell disability payments.

Two years ago, at the time the Army acknowledged administering LSD to thousands of soldiers in a test program at Edgewood Arsenal in northwestern Maryland, it said that one unidentified U.S. soldier had been given the drug during a criminal interrogation in the "Third Chance" project, but that his whereabouts was unknown.

Thornwell, in a two-hour interview with The Washington Post, vividly recalled details of this interrogation which occurred between March and June, 1961, but he said he did not know about the LSD tests.

Since his discharge, Thronwell said, he has been unable to hold a job for more than two months at a time or to deal with any situation involving stress or pressure.

Army documents say Thornwell was evaluated by a psychiatrist before he was given sodium pentothal and phynosis during his interrogation. The report suggests, but does not say specifically, that Thornwell was deemed mentally fit for such examinations. But the report on "Third Chance," written by Lt. Col. William Jacobson, gives several clues that Thornwell may have been unbalanced by his experiences.

The report indicates that Thorn well, identified as "Private J.R.T." reacted strongly to LSD and that interrogation was difficult. Among the points it makes is the following:

"The usefulness of employing as a duress factor the device of inviting the subject's attention to his EA 1729 influenced state and threatening to a permanent condition of insanity, or to bring it to an end at the discretion of the interrogators, was shown to be effective."

EA 1729 was the Army designation for LSD.

On Oct. 21, 1975, a report from Lt. Gen. H. N. Maples, the inspector general to the Army chief of staff said that Thornwell was not tired for his alleged crime because of the prolonged interrogation, and an effort not to reveal the existence of the "Special Purpose Team" that interrogated him. "The possibility of unfavorable publicity resulting from Thornwell's recollection of the bizarre methods employed by the D.A. [Department of Army] Special Purpose Team" and the unanimous opinion of the psychiatrists who evaluated Thornwell that he had "severe psychiatric disorders."