Dr. Drew Scott Disick Is in Desperate Shape

3/23/2015 6:40 AM PDT

Dr. Drew -- Scott Disick Is in Desperate Shape (VIDEO)

EXCLUSIVE

Dr. Drew believes Scott Disick is in far worse shape than anyone believes, because his choice of rehab is dangerous, generally used by heroin addicts, and he's destined to relapse.

The good doc was at LAX Sunday when our photog asked about Disick's decision to leave the Costa Rica rehab facility Monday, after only one week of treatment. Scott says he has pressing business in L.A., but Drew says it's a common rich-people's avoidance technique.

Dr. Drew seemed alarmed Scott was being treated with a hallucinogenic plant called Iboga, saying it's usually used for heroin addiction, not alcohol, and it's very dangerous.