It is likely that patients participating in clinical trials related to serious diseases will find higher rates of pay from clinical trials. These are areas like neurology, cardiovascular disease, endocrinology, blood diseases, and gastrointestinal medicine. Paying participants to participate in clinical research projects is not a new practice. In 1900, Water Reed paid patients US$100 to get bitten by mosquitoes infected with yellow fever, according to the National Center for Biotechnology Information. An additional prize of $100 was awarded to patients infected with the disease. Given the potential risk, you should take the time to carefully review the consent document offered by researchers when considering participating in a clinical trial. But there are also drawbacks and challenges to consider.