Lamar Odom -- High As a Kite But Vows to Play Basketball

Lamar Odom is drugged out of his head ... but he's telling people he will sober up and play basketball again this coming season ... yes, he's that delusional.

Sources who have been spending time with Lamar tell us his drug problem is out of control -- that one of his drug dealers alone has sold him thousands of dollars in coke. We're told Lamar is now freebasing with pure cocaine.

As crazy as it sounds ... Lamar has done it before. We know he was using while on the Lakers and on the Mavericks. In addition, he was off the rails using drugs just months before joining the Clippers but cleaned up enough to get through the season.

We're told Lamar is full-on paranoid now ... he believes people are trying to set him up to get caught. As he told one friend, "Everyone wants to see me fail, but I'm not gonna let that happen."