Clinical trials are research studies that look at new ways to prevent, detect, or treat diseases and conditions, including depression. During clinical trials, some participants receive treatments under study that might be new drugs or new combinations of drugs, new surgical procedures or devices, or new ways to use existing treatments. Other participants (in the “control group”) receive a standard treatment, such as a medication already on the market, an inactive placebo medication, or no treatment. The goal of clinical trials is to determine if a new test or treatment works and is safe. Although individual participants may benefit from being part of a clinical trial, participants should be aware that the primary purpose of a clinical trial is to gain new scientific knowledge so that others may be better helped in the future.