Therapeutic trial participants: where do we find them and what does it cost?

Billions of dollars are spent annually in the process of developing and marketing new therapeutic agents. While the methods for testing and assuring safety of these newer agents receive intense scrutiny, the methods by which the patient samples for psychotropic agent studies are recruited has received relatively little attention. It appears that symptomatic volunteers who enter clinical psychopharmacology studies are clinically comparable to treatment-seeking patient samples. There is almost no information regarding the actual proportions of "recruited" to treatment-seeking patients or how many symptomatic volunteers participate in more than one study, and the expense of advertising for symptomatic volunteers has not been investigated. We surveyed 18 experienced investigators around the United States to identify: (1) the relative proportion of clinical trial participants who are symptomatic volunteers versus treatment-seeking patients; (2) the proportion of study volunteers who entered more than one clinical trial; and (3) the cost of recruitment for investigators who conduct these studies. The findings indicate that an average of 87.2 percent of subjects entering trials were recruited via advertising. Most participate in only one study. The expense of identifying and recruiting appropriate symptomatic volunteers is significant, and appears to be increasing. Implications of these findings will be discussed.