Nick Gordon -- Checks into Rehab After Dr. Phil Taping

Nick Gordon checked into rehab for drugs after ranting he might kill himself during a taped appearance with Dr. Phil.

Bobbi Kristina's boyfriend sat down with Dr. Phil in Atlanta earlier this week for what he thought would be an interview -- but we're told it was more like an intervention organized by Phil and Gordon's mother.

During the taping, Gordon talked about committing suicide if Bobbi Kristina didn't pull out of the coma. We're told Gordon's mother complained her son was severely depressed and abusing drugs.

It's unclear where Gordon is getting treatment and for how long.