PHILADELPHIA (AP) — Paul George of the Philadelphia 76ers was suspended 25 games for violating the terms of the NBA’s anti-drug program, the league announced Saturday.

The NBA did not disclose the nature of the violation or the substance that was involved, and George released a statement to ESPN saying he took something that was “improper.”

“Over the past few years, I’ve discussed the importance of mental health, and in the course of recently seeking treatment for an issue of my own, I made the mistake of taking an improper medication,” George said in the statement released to the network.

He apologized to the team and its fans, saying he takes “full responsibility for my actions.”

The 25-game suspension, by terms of the agreement between the NBA and the National Basketball Players Association, indicates that this was a first violation by George. He will begin serving the suspension Saturday when Philadelphia hosts New Orleans.