Dr. Drew Says George Michael's Death Wasn't Natural, Suspects Drugs and Booze

Dr. Drew isn't buying the coroner's report about George Michael dying of natural causes ... because there were too many markers of substance abuse.

We got the good doc Tuesday night at Catch and he was pretty fired up about the official report because, as he puts it ... there's NOTHING natural about the contributing causes.

Drew argues Michael's heart and liver issues scream alcohol and drug abuse ... at least to him they do.