This study of mental health as (a) functional (or dysfunctional) adaptation over 40 to 50 years of the life span, and (b) as accommodations to aging at late maturity, would be based on analyses of archival and newly collected data for members of three longitudinal studies and their spouses. The central, interdisciplinary and multifaceted program of data collection has already been funded. Its administrators have set the goal of recalling approximately 325 index cases, who are modally in their mid-50s and early 60s, along with their some 300 spouses, starting on Nov. 1, 1981. Archival data on personality, life events, social milieux, and health already exist for the index cases at five to seven points in time as do prior middle adulthood data for the spouses. This application is to support collection of supplementary data, all analyses, and report-writing. To address the antecedents, interactions and sequencing of the multifaceted aspects of mental health over time, the following longitudinal data domains will be used: (a) personality--time specific statuses, developments, and shifts; (b) contextual experiences of stress as adventitious or as life course events, (c) earlier health history and status at late maturity, (d) history and current networks of social support that may modify or exacerbate stress, and (e) ways of accommodating to aging during the transitional period of late maturity. The analytic conceptualization is interactional in the strong sense, but the person is regarded as the center of transaction. Among expected results are elucidation of (a) the nature of life-span developmental curves after variances associated with nonsystematic effects of adventitious stress are removed, (b) the stress experiences and personality characteristics that lead to personal deterioration or growth, (c) the personal, social, and health conditions of accumulated stress over the life span that lead to mental health rather than to decompensation, and (d) the personal, social and health histories that lead to the differing ways that people adapt to their own aging.