Jackson's condition was described in an affidavit provided by Methodist Hospital emergency physician Dallas Peak after a federal judge sought proof of the 44-year-old pop star's illness when he failed to appear to give a court-ordered deposition in a copyright lawsuit on May 21.
The singer was briefly hospitalized when he fell ill before the deposition could begin. He was released about two hours later and returned home to Los Angeles.
Jackson's attorney, Brian Oxman, has said the singer sometimes became nervous and failed to eat when faced with depositions.
Peak said in the affidavit that Jackson was treated with intravenous fluids and a tranquilizer to prevent him from fainting. Jackson's personal physician also provided an affidavit regarding the singer's health.
Richard Feldman, an executive at St. Francis Hospital and Health Centers and former state health commissioner, said the events described in the affidavits were consistent with an anxiety attack. A patient would not be advised to participate in an hourslong testimony after being given a tranquilizer, Feldman said.
Judge Philip Simon ordered Jackson to return to Indianapolis by June 13 to complete the deposition, and warned he might fine Jackson $1,000 per day for the delay.
Simon had ordered Jackson to give a deposition in a lawsuit alleging that the Jackson Five used the name of another Gary band and two of their songs without license.
Gordon Keith, the man who signed the Jackson Five to his Gary-based Steeltown Records in 1967, and musician Elvy Woodard accuse Michael, Jackie, Tito, Jermaine and Marlon Jackson of infringing on the trade name Ripples & Waves, which was the name of another Gary band during the 1960s.