ElChupacabra, to add to the others, they're right on the whole being "intelligent" opposed to being well educated with a reputable position, such as an attorney, doctor, therapist, scientist, etc. Addiction does not discriminate at all.
I work with a lot of addicts, we happen to have a professor among the bunch as well as several registered nurses, many educated women with degrees and young girls who are still attending college while they work on their recovery.