PARTICIPATING IN CLINICAL TRIALS   Through the ages, disorders of the mind have been among the most devastating and feared illnesses of humanity. Today, thanks to ambitious and productive research and to the many individuals willing to participate in this research, highly effective treatments for mental illnesses now exist. As a result of these treatments, many thousands of people who have brain diseases such as depression, bipolar disorder, schizophrenia and anxiety disorders lead fulfilling and productive lives.   Scientists study and try different ways to diagnose, treat, and prevent human disease more effectively. The needed research may take place in a basic science laboratory, a clinic, or in the community.   Some clinical research may examine how well a treatment works -- perhaps a drug or other type of therapy. In other instances, a clinical study might explore factors that affect mental disorders such as the role of genes and their interactions with life experiences.   To help you make your decision about participating in a research study, the National Institute of Mental Health (NIMH) has prepared a booklet to answer some of your questions and list questions that you will want to ask the clinical study director. You can call the Mental Health Association of Broward County at 954-746-2055 to request a copy of this booklet.   There are many clinical trials available including those from private organizations and governmental entities. You can find a list of current research projects at www.clinicaltrials.gov   It is our hope that by helping people better understand why they might consider participation in the clinical research of mental illnesses, all persons will benefit in the years ahead.