There are ethical considerations in all clinical trials, and participation can have personal and societal benefits.  It is important that research be done ethically at all times.   

Both medical therapy and clinical trials are governed by law and strict ethical codes.  Does that mean that all ethical questions have been solved?  Not at all.  There are still many unknowns and even competing ethical principles that surface in standard clinical practice.  Because research is a leap into the unknown by its very nature, the complexity of ethical issues with clinical trials is infinitely greater.

The most basic of ethical dilemmas surrounds why people participate in clinical trials.  When someone chooses to enroll in the hope that the study will possibly yield a cure for others in the future, there's no conflict.  But, statistics show that most people sign up for the chance of a cure for themselves.  Should we protect desperate people from unnecessary discomfort that might be involved in a clinical trial and disappointment if they don't receive a benefit?  Or, should they be encouraged to continue to hope, despite the odds?

Researchers and regulators walk the fine line of defining good ethical practice every day.  Basic principles demand that:

• The trial is scientifically worthy and well designed
• Those conducting the trial are qualified
• Those conducting the trial are free of bias, including issues related to financial interests 
• Risks are as low as possible and are reasonable when compared to the importance of what may be learned
• Studies are suspended or terminated if the risks turn out to be greater than expected
• Participants are given the information they need and in a form they can understand so they can make an informed choice about whether to volunteer or to stay in the trial
• Neither coercion (such as a threat of harm) nor undue influence (such as an excessive reward) is used to persuade someone to enroll
• The selection of subjects and assignment to groups is equitable

Initially, these sound straightforward.  But, on closer inspection, these seemingly simple concepts are not always as clear-cut as they seem.  For example, the majority of clinical trials assign participants to groups.  One group receives the new therapy; the other group (or groups) receives either the standard treatment for their disease or a placebo.  Assignment is done by chance (called randomization).  While the potential for bias is removed by random selection, the fact remains that unless both therapies turn out to be equal some people will receive inferior treatment. 

Medical research holds ethical questions for society at large as well as for the individuals who are involved in them.  Right now the use of stem cells is being hotly debated at all levels of government and the scientific community.

Stem cells are undifferentiated cells that have the potential to develop into any cell type in the body. In the case of Parkinson's disease, researchers hope that stem cells can be coaxed into becoming healthy dopamine neurons, which can then be transplanted into the brain. 

Much of the controversy surrounding the use of stem cells has to do with how they're obtained. Harvesting embryonic stem cells destroys the embryo (though researchers are now working on promising ways to prevent this).  Right-to-life advocates view embryo destruction as equivalent to murder.  Another technique is to use a person's own genetic material to source stem cells.  The process is called therapeutic cloning and many fear it to be the first step on the path to the reproductive cloning of humans.

Bottom line, ethics is anything but an exact science and there's rarely one correct answer for any issue.  While clinical trials are conducted far more ethically and are far safer now than they were thirty years ago, many ongoing dilemmas remain to be debated and resolved.