A staffer at Straight Inc., a drug rehabilitation agency, testified in federal court in Alexandria yesterday that he "diagnosed" that college student Fred Collins had a drug problem because Collins had red eyes "symptomatic of marijuana use" during an interview.

Christopher Yarnold, who interviewed Collins at Straight's branch in St. Petersburg, Fla., conceded under questioning that Collins told him he had not smoked marijuana in more than three months.

Collins, 20, a sophomore at Virginia Tech, is seeking $750,000 in damages from Straight Inc. in U.S. District Court, contending that he was forced to remain in the program for 130 days and subjected to constant mental and physical abuse. Collins' family lives in Fairfax, where the agency recently opened a drug treatment program.

Dr. James Egan, the chief of psychiatry at Children's Hospital in Washington, testified yesterday that Collins was "a typical, perhaps above average" student whose drug and alcohol use was "modest by contemporary standards."

Egan told the jury that he would not have referred Collins to a rehabilitation program. Egan testified that he believes that Collins has developed "neurotic symptoms" such as depression, anxiety and nightmares since he left the Straight program.

Defense lawyers for Straight deny that Collins was subject to any physical or psychological abuse. They contend that the program, which they say Collins joined voluntarily, is based on nationally accepted therapeutic practices.

During Yarnold's testimony yesterday, Collins' chief counsel, Philip J. Hirschkop, invited the staffer to come down from the witness stand and look into Collins' eyes, and "tell the court when he had his last drink."

Yarnold then walked up to Collins, who was seated in the well of the courtroom, looked into his eyes and said, "They look good."

Joey Glaze, 17, a Straight staffer who also helped admit Collins to the program, testified that Collins stood up at a "group rap" in St. Petersburg and said he was thinking of leaving the program. Glaze wrote in the staff book that evening that "Fred Collins was confronted and blown away for wanting to leave. We need to ride his butt." Glaze told the jury that meant staffers needed to concentrate on helping Collins.

Collins' attorneys also tried to show a pattern of abuse in the Straight facilities that would have intimidated Collins. Leigh Bright of Oxon Hill, who was in the program with Collins in St. Petersburg, testified that she had a confrontation with program director Miller Newton, now Straight's national clinical director. Bright told the jury that Newton "grabbed me by the hair and threw me to the floor" and called her obscene names.

Newton was called as the first defense witness late yesterday and is expected to continue his testimony today.