The official cause of 22-year-old Emily McCaughan's death was "multiple blunt-force injuries," the office told the Weekly.
But other significant conditions included multiple drugs in her system, the office said:
Examiners determined that, along with ecstasy, she had methamphetamine and so-called date-rape drug GHB, or gamma-hydroxybutyric acid, in her system when she died last June. The drugs combined to produce "intoxication," the office said.
McCaughan told friends she thought she was being followed and wanted to go back to her room at the Circus Circus hotel on the Las Vegas Strip as they attended the last night of EDC June 11.
She went back and then fell 20 stories to her death.
Friends immediately said she had taken ecstasy, or MDMA, even though the drug is not known for inducing paranoia. Meth is a chemical component of MDMA (3,4-methylenedioxy-N-methylamphetamine), so it's not clear if she took additional methamphetamine on its own.
GHB is generally thought of as a relaxant, but it can cause anxiety.
McCaughan's was one of two deaths that rocked the Vegas edition of EDC, an L.A.-based rave franchise that left town last year following the death of a 15-year-old girl who sneaked into the L.A. Coliseum to attend the party only to overdose on ecstasy.