Additional Study Information: Depression affects 15 million Americans each year. Depression and suicidal behavior are transmitted in families due to a combination of genes and environment. Depressive illness and the risk of suicidal behavior are associated with altered brain function that we can detect with brain imaging. Therefore, this study aims to examine brain function in adults who have depression and may or may not have a family history of suicide attempt. Procedures include brain imaging (MRI, PET, and fNIRS), behavioral testing, and clinical assessments. Monetary compensation of up to $1150 is offered for expenses in undergoing all the scans and interviews.