The Clinical Evaluation and Follow-Up Core/Course of Illness Laboratory (CIL) will have three related functions: 1) The CIL will be the resource for research subjects for the current and future investigators using the CRC/GAD. Consistent with the research philosophy of the CRC/GAD, the CIL will recruit a broad sample of elderly patients with affective and other psychiatric syndromes and appropriate controls and will provide longitudinal systematic clinical assessment. Subject recruitment will be guided by the needs of the projects of the CRC/GAD that are being selected by the Director and the Executive Committee of the CRC/GAD. The CIL will take advantage of the unique geriatric population of our Center. The Director and Co-Director of the CIL have experience as funded investigators of longitudinal studies in geriatric affective disorders and will direct a program of studies aiming at improving the methodology of clinical assessment, including instrument development, phenomenological studies of specific affective syndromes, and studies attempting to improve the methods of assessment of history of illne . 2) The CIL will be a resource for consultation and training of junior investigators in methods of longitudinal clinical assessment of geriatric patients. 3) The CIL will function as a research laboratory with a program focusing on studies of relapse and recurrence of geriatric affective syndromes. The unifying hypothesis of its program will be that the heterogeneity of geriatric affective disorders influences their outcome. Therefore, studies of outcome performed at the CIL are designed to identify subtypes that will be appropriate for focused biological investigations. In addition, the CIL will seek to examine the risk/benefit ratio of continuation and maintenance therapies in recovered depressives and manics and develop guidelines for prevention of relapses and recurrences in this frail elderly population. This research agenda will be pursued by supporting several funded studies on depression and mania, as well as two pilot projects examining predictors of outcomes and effect of continuation and maintenance treatment in psychotic and non-psychotic depression.