An Oklahoma teen who died in February, reportedly a day after being attacked at their high school, died of an overdose, authorities said on Wednesday.

A summary autopsy report stated that Nex Benedict — a nonbinary 16-year-old who used they/them pronouns — died on February 8 from a combination of diphenhydramine, an antihistamine, and fluoxetine, an anti-depression medication. The Oklahoman reported that Benedict had been bullied over the years about their gender identity.

Owasso police said in a statement that they obtained evidence early on in their investigation which suggested Benedict took their own life. However, they said they withheld publicizing this information as they awaited the medical examiner’s determination.

According to KFOR, three girls were picking on Benedict and their friends before the group attacked Benedict for pouring water on them. Benedict’s parents contacted the police about the attack which occurred in the girls’ bathroom at Owasso High School West Campus. School officials allegedly never reported the incident, but a school resource officer took a report at the hospital.

The full autopsy report is expected to be released this month. Meanwhile, police are still investigating the February 7 altercation and whether Benedict was the victim of gender-based violence.