Matt Roberts, the original lead guitarist for 3 Doors Down, was found dead in a hotel outside of Milwaukee on Saturday morning. He was 38.

While a cause of death is currently unknown, his father, Darrell Roberts, said his son has had problems with anxiety and prescription drugs. He told TMZ that he believes an accidental overdose is to blame.

“I know he had prescription drug addiction. He suffered greatly from anxiety,” Darrell Roberts told CNN. “This was his way of dealing with it.”

Police responded to a call about a man who was either passed out or asleep in the hallway at the Hampton Inn in West Bend, Wis., at about 7 a.m. on Saturday morning. Emergency responders were unable to revive the man, who was identified as Roberts. An autopsy was scheduled for Sunday.

Roberts was in Wisconsin preparing to perform at a Saturday night concert at the Our Place bar, benefiting veterans organization Stars and Stripes Honor Flight. His father, in a video posted on the West Bend Daily News’ Facebook page, took the stage that night to address the crowd and dedicate the concert to Roberts.

Roberts co-founded 3 Doors Down with friends Brad Arnold and Todd Harrell in 1996 in their hometown of Escatawpa, Miss. The band found success through touring and in 2000 released its first studio album, “The Better Life,” which went six times platinum.

3 Doors Down scored with hits such as “Here Without You” and “When I’m Gone,” but it was the first single off the album, “Kryponite,” that propelled it to international stardom. The single hit No. 3 on the Billboard Hot 100 Chart.

Roberts left the band in 2012, citing health problems. He said “circulation issues” and a rigorous performing schedule forced him to take a break.