Months after the shocking death of Bartusiak, officials ruled the tragedy an accidental overdose, reported People magazine.
She died in her sleep at her Texas home in July. She was just 21.
According to the Harris County Institute of Forensic Sciences, the primary cause of death was the combined toxic effects of hydrocodone and difluoroethane with carisoprodol.
Difluoroethane is a colourless gas used as a refrigerant to get a high. Carisoprodol is a muscle relaxer.