Coroners Determine Cause of Death for Marie Osmond’s Son

 Steven Lawton/FilmMagic; ET

Los Angeles Coroners have officially determined the cause of death for Marie Osmond's 18-year-old son Michael Bryan, UsMagazine.com has learned — and no drugs were involved.

Autopsy findings confirm that Bryan died from "multiple blunt trauma" after jumping from the eighth floor of his L.A. apartment building Feb. 26. No drugs were found in his system; Bryan had struggled with substance abuse as well as depression, and entered a rehab in 2007.

Michael was one of Marie's five adopted children (she had eight children overall) with her ex-husband, Brian Blosil. (Michael had changed his last name from "Blosil" to "Bryan.")

Before his death, he had been a student at L.A. Fashion Institute of Design and Merchandising. "He was always smiling," a grieving, perplexed pal told Us. Yet Bryan left a despondent note for a friend mintues before taking his own life.

"He was a man of his word. He wasn't a talker, he was a doer. He was reliable," his 20-year-old sister Rachel Blosil eulogized at his March 8 funeral in Provo, Utah.

On Tuesday, Marie Osmond, 50, re-emerged on Twitter to thank her supporters. "Your messages have been so sweet," she wrote. "Thank you so much. I'm grateful for all of you."

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