My former study buddy/ roommate did a study there once. Apparently he had some history of drug use, although never when i knew him. the study they did was to test formulations of the drug designed to be so unpleasant to take that drug addicts wouldn't crush and snort the pills. so it was an unpleasant study but paid well.
what i've been hearing about this place is that the site will say "no studies at this time" but they do get studies they don't list, so if you get in good with the recruiter or call every day or know somebody, you might pick up a study there. that is true of a lot of clinics, but this one especially.