Objectives-This article uses data from MIDUS (Midlife in the United States), a national study of Americans (N = 7,108), to investigate factors that predict longitudinal retention. With its extensive age range (25-75 at Time 1) and long-term design (9-to 10-year survey interval), MIDUS is useful for investigating common sociodemographic and health predictors of continuing participation.Method-The authors conducted logistic regression analyses of baseline sociodemographic and health variables predicting retention. Select interaction terms examined the interplay between targeted variables.Results-Consistent with prior research, higher retention rates were found among Whites, females, and married individuals as well as those with better health and more education. Interaction analyses further clarified that (a) health status better predicted retention among older compared to younger respondents and among women compared to men, (b) marital status better predicted retention among Whites compared to non-Whites and among women compared to men, and (c) economic status better predicted retention among those with poorer functional health status.Discussion-The authors' analyses clarify that longitudinal retention varied depending on respondents' sociodemographic characteristics and their health status. The unique contribution of this article is that factors predicting nonparticipation can be offset by, or compensated for, other factors. Keywords aging; longitudinal retention; demographics; healthWho is likely to participate in the second wave of a large, national health study? Despite variation in samples, research design, and mode of assessment, prior studies have shown evidence of differentiated probabilities of response (or nonresponse) due to selective sociodemographic and health characteristics (Fitzgerald, Gottschalk, & Moffitt, 1998; Kapteyn, Michaud, Smith, & van Soest, 2006;Lindenberger et al., 1999). We draw on this work to examine predictors of longitudinal retention in the second wave of the MIDUS (Midlife in the United States) national survey. We highlight longitudinal retention rather than attrition because studies focused on attrition and/or nonresponse tend to be concerned with bias and related methodological adjustments (e.g., sample weights based on various assumptions about nonresponders compared to responders). The emphasis on retention, in contrast, addresses characteristics of the Time-2 respondents on whom subsequent longitudinal findings will be Corresponding Author: Barry T. Radler, PhD, 2245 Medical Science Center, University of Wisconsin-Madison, 1300, University Avenue, Madison, WI 53706, bradler@wisc.edu. Declaration of Conflicts of InterestThe authors declared no potential conflicts of interest with respect to the authorship and/or publication of this article. NIH Public AccessAuthor Manuscript J Aging Health. Author manuscript; available in PMC 2010 April 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript generated. Such information underscores the importance...

Eudaimonic well-being—a sense of purpose, meaning, and engagement with life—is protective against psychopathology and predicts physical health, including lower levels of the stress hormone cortisol. Although it has been suggested that the ability to engage the neural circuitry of reward may promote well-being and mediate the relationship between well-being and health, this hypothesis has remained untested. To test this hypothesis, we had participants view positive, neutral, and negative images while fMRI data were collected. Individuals with sustained activity in the striatum and dorsolateral prefrontal cortex to positive stimuli over the course of the scan session reported greater well-being and had lower cortisol output. This suggests that sustained engagement of reward circuitry in response to positive events underlies well-being and adaptive regulation of the hypothalamic-pituitary-adrenal axis.

BackgroundPsychological correlates of blood lipid levels have been previously evaluated mostly in cross sectional studies. However, prospectively measured psychological factors might also predict favorable blood lipid profiles, thereby indicating a healthy mind/body interplay that is associated with less disease, better health and longer lives.MethodsThis paper examined whether longitudinal profiles of psychological well-being over 9–10 years are predictors of blood lipid profiles. Using the MIDUS (Midlife in the U.S.) biological subsample (n = 1054, aged 34 to 84, 55% female), cross-time trajectories of well-being were linked with three lipid outcomes (i.e., HDL cholesterol, triglycerides, and LDL cholesterol), measured for the first time at the 2nd wave of the study.ResultsMost adults showed largely stable profiles of well-being, albeit at different levels. Some showed persistently high well-being over time, while others revealed persistently low or moderate well-being. After adjusting for the effect of demographics, health behaviors, medications, and insulin resistance, adults with persistently high levels of environmental mastery and self-acceptance—two components of psychological well-being—had significantly higher levels of HDL as well as significantly lower levels of triglycerides compared to adults with persistently low levels of well-being. Converging with prior findings, no association was found between well-being and LDL cholesterol.ConclusionsOver 9–10 years, persistently high levels of psychological well-being measures predicted high HDL cholesterol and low triglycerides. These findings add longitudinal evidence to the growing body of research showing that positive psychological factors are linked with better lipoprotein profiles. A better blood lipid profile, particularly higher HDL-C, may be key in mediating how psychological well-being positively impacts health and length of life. Additional research is required to further validate this hypothesis as well as to establish potential underlying mechanisms.