 Genetic screening will help to enhance researchers understanding of the role of dopamine receptors in depression. A small blood sample, about 2 tablespoons, will be collected, to isolate DNA from blood cells. Some of the blood samples or DNA may be stored for future studies, but those samples will remain coded, so participants will not be identified. This study will not have a direct benefit for participants. However, the results may provide knowledge to help people in the future. This study does involve compensation. 