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In 1995-1996, the MacArthur Midlife Research Network carried out a national survey of over 7,000 Americans aged 25 to 74 (ICPSR 2760). The purpose of the study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health.

With support from the National Institute on Aging, an initial follow-up of the original Midlife Development in the United States (MIDUS) samples was conducted in 2004 (MIDUS 2). The daily stress and cognitive functioning projects were repeated at MIDUS 2; in addition the protocol was expanded to include biomarkers and neuroscience. In 2005, a baseline sample of 592 African Americans from Milwaukee was added to MIDUS to examine health issues in minority populations.

In 2013, a third wave (MIDUS 3) of survey data was collected on longitudinal participants. Data collection for this follow-up wave largely repeated baseline assessments (e.g., phone interview and extensive self-administered questionnaire), with additional questions in selected areas (e.g., economic recession experiences, optimism and coping, stressful life events, and caregiving). A third wave of cognitive functioning data and a second wave of the Milwaukee sample were also collected. Data collection for the daily diary, biomarkers, and neuroscience is ongoing. This dataset includes all known MIDUS decedents (N=2,533) from the Core National and Milwaukee samples as of December 2023.

The Midlife in the United States (MIDUS) is a collaborative, interdisciplinary investigation of patterns, predictors, and consequences of midlife development in the areas of physical health, psychological well-being, and social responsibility. A description of the study and findings from it are available at http://www.midus.wisc.edu.

The first wave of the MIDUS study (MIDUS 1 or M1) collected survey data from a total of 7,108 participants. The baseline sample was comprised of individuals from four subsamples: (1) a national RDD (random digit dialing) sample (n=3,487); (2) oversamples from five metropolitan areas in the U.S. (n=757); (3) siblings of individuals from the RDD sample (n=950); and (4) a national RDD sample of twin pairs (n=1,914). All eligible participants were non-institutionalized, English-speaking adults in the coterminous United States, aged 25 to 74.

Data from the samples were collected primarily in 1995/96. The survey (Project 1) dataset contains responses from a 30-minute Phone interview and two 50-page Self-Administered Questionnaire (SAQ) instruments. Of the 7,108 respondents who completed the Phone interview, 6,325 also completed the SAQ.

This updated version of the study is comprised of three primary datasets:

Dataset 1, Main, Siblings, and Twin Data, contains responses from the main survey of 7,108 respondents. Respondents were asked to provide extensive information on their physical and mental health throughout their adult lives, and to assess the ways in which their lifestyles, including relationships and work-related demands, contributed to the conditions experienced. Those queried were asked to describe their histories of physical ailments, including heart-related conditions and cancer, as well as the treatment and/or lifestyle changes they went through as a result. A series of questions addressed alcohol, tobacco, and illegal drug use, and focused on history of use, regularity of use, attempts to quit, and how the use of those substances affected respondents' physical and mental well-being. Additional questions addressed respondents' sense of control over their health, their awareness of changes in their medical conditions, commitment to regular exercise and a healthy diet, experience with menopause, the decision-making process used to deal with health concerns, experiences with nontraditional remedies or therapies, and history of attending support groups. Respondents were asked to compare their overall well-being with that of their peers and to describe social, physical, and emotional characteristics typical of adults in their 20's, 40's, and 60's. Information on the work histories of respondents and their significant others was also elicited, with items covering the nature of their occupations, work-related physical and emotional demands, and how their personal health had correlated to their jobs. An additional series of questions focusing on childhood queried respondents regarding the presence/absence of their parents, religion, rules/punishments, love/affection, physical/verbal abuse, and the quality of their relationships with their parents and siblings. Respondents were also asked to consider their personal feelings of accomplishment, desire to learn, sense of control over their lives, interests, and hopes for the future.

The Datasets previously numbered 2 and 3 have been removed to avoid redundancies, and all datasets have been renumbered. Please refer to the readme file.

Dataset 2, Twin Screener Data, provides the first national sample of twin pairs ascertained randomly via the telephone.

Dataset 3, Coded Text Responses, describes how open-ended textual responses in the MIDUS 1 Computer-Assisted Telephone Interview (CATI) and Self-Administered Questionnaire (SAQ) were transformed into categorical numeric codes. These codes are included in a stand-alone dataset containing only those cases (N=3,950) that contained text data in their responses.

Online Analysis Only: Datasets 1, 2, and 3 were merged together by the SU_ID variable to form "Merged Data with Weights (Online Analysis Only)" (Dataset 4) for online analysis capabilities.

MIDUS also maintains a Colectica portal, which allows users to interact with variables across waves and create customized subsets. Registration is required.

In 1995-1996, the MacArthur Midlife Research Network carried out a national survey of 7,108 Americans aged 25 to 74 (MIDLIFE IN THE UNITED STATES (MIDUS), 1995-1996 [ICPSR 2760]). The purpose of the study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. The study was innovative for its broad scientific scope, its diverse samples (which included twins and the siblings of main sample respondents), and its creative use of in-depth assessments in key areas (e.g., daily stress and cognitive functioning). A description of the study and findings from it are available at http://www.midus.wisc.edu. With support from the National Institute on Aging, a longitudinal follow-up of the original MIDUS samples: core sample (N = 3,487), metropolitan over-samples (N = 757), twins (N = 925 complete pairs), and siblings (N = 950), was conducted in 2004-2006. Guiding hypotheses for it, at the most general level, were that behavioral and psychosocial factors are consequential for physical and mental health. MIDUS 2 respondents were aged 35 to 86. Data collection largely repeated baseline assessments (e.g., phone interview and extensive self-administered questionnaire), with additional questions in selected areas (e.g., cognitive functioning, optimism and coping, stressful life events, and caregiving). To add refinements to MIDUS 2, an African American sample (N = 592) was recruited from Milwaukee, Wisconsin, who participated in a personal interview and completed a questionnaire paralleling the above assessments. Survey data for the Milwaukee sample are available in a separate project [ICPSR 22840]. Also administered was a modified form of the mail questionnaire, via telephone, to respondents who did not complete a self-administered questionnaire.

The Biomarker study is Project 4 of the Midlife in the United States (MIDUS) longitudinal study, a national survey of more than 7,000 Americans (aged 25 to 74) begun in 1994. The purpose of the larger study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. With support from the National Institute on Aging (NIA), a longitudinal follow-up of the original MIDUS samples [core sample (N = 3,487), metropolitan over-samples (N = 757), twins (N = 957 pairs), and siblings (N = 950)] was conducted in 2004-2006. Guiding hypotheses, at the most general level, were that behavioral and psychosocial factors are consequential for health (physical and mental). A description of the study and findings from it are available on the MIDUS website.

The Biomarker Project (Project 4) of MIDUS 2 contains data from 1,255 respondents. These respondents include two distinct subsamples, all of whom completed the Project 1 Survey: (1) longitudinal survey sample (n = 1,054) and (2) Milwaukee sample (n = 201). The Milwaukee group contained individuals who participated in the baseline MIDUS Milwaukee study, initiated in 2005. The purpose of the Biomarker Project (Project 4) was to add comprehensive biological assessments on a subsample of MIDUS respondents, thus facilitating analyses that integrate behavioral and psychosocial factors with biology. The broad aim is to identify biopsychosocial pathways that contribute to diverse health outcomes. A further theme is to investigate protective roles that behavioral and psychosocial factors have in delaying morbidity and mortality, or in fostering resilience and recovery from health challenges once they occur. The research was not disease-specific, given that psychosocial factors have relevance across multiple health endpoints.

Biomarker data collection was carried out at three General Clinical Research Centers (at UCLA, University of Wisconsin, and Georgetown University). The biomarkers reflect functioning of the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, the immune system, cardiovascular system, musculoskeletal system, antioxidants, and metabolic processes. Our specimens (fasting blood draw, 12-hour urine, saliva) allow for assessment of multiple indicators within these major systems. The protocol also included assessments by clinicians or trained staff, including vital signs, morphology, functional capacities, bone densitometry, medication usage, and a physical exam. Project staff obtained indicators of heart-rate variability, beat to beat blood pressure, respiration, and salivary cortisol assessments during an experimental protocol that included both a cognitive and orthostatic challenge. Finally, to augment the self-reported data collected in Project 1, participants completed a medical history, self-administered questionnaire, and self-reported sleep assessments. For respondents at one site (UW-Madison), objective sleep assessments were also obtained with an Actiwatch(R) activity monitor.

In 1994/1995, the MacArthur Midlife Research Network carried out a national survey of over 7,000 Americans aged 25 to 74. The purpose of the study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. A description of the study and findings from it are available at the MIDUS website.

With support from the National Institute on Aging, a longitudinal follow-up of the original MIDUS samples (core sample (N = 3,487), metropolitan over-samples (N = 757), twins (N = 957 pairs), and siblings (N = 950)) was conducted in 2004-2006. Guiding hypotheses, at the most general level, were that behavioral and psychosocial factors are consequential for health (physical and mental). The purpose of the Cognitive Project was to determine how cognition is related to overall mental and physical health. Specific goals were: (1) to characterize the nature and range of midlife cognitive performance, relative to those younger and older, across multiple domains in a nationally representative sample (MIDUS); and (2) to examine the relationship between biopsychosocial factors (e.g., SES, health status, health-promoting behaviors, metabolic and cardiovascular biomarkers, depression, personality, control beliefs, stressful life events) and individual differences in cognitive functioning.

The development of a cognitive battery for the second wave of testing of the Midlife Development in the United States (MIDUS) study provided an opportunity to examine the cognitive performance of young, middle-aged and older adults from a wide range of education levels in a large-scale, national sample. As part of the Cognitive Project of the MIDUS II the Brief Test of Adult Cognition by Telephone (BTACT) (Lachman & Tun, 2008; Tun & Lachman, 2006) was administered. More information about the BTACT can be found at the Brandeis website. The BTACT represents the first comprehensive cognitive battery, including measures of speed and reaction time, to be administered by telephone to a national sample across the adult years and into later life. With a response rate of over 86 percent for the cognitive testing component of the MIDUS II, a cognitive data set of unprecedented range in terms of age, gender, socioeconomic status (SES), education, and geographic diversity was produced.

The Neuroscience study is Project 5 of the MIDUS longitudinal study, a national survey of more than 7,000 Americans (aged 25 to 74) begun in 1994. The purpose of the larger study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. With support from the National Institute on Aging, a longitudinal follow-up of the original MIDUS samples [core sample (N = 3,487), metropolitan over-samples (N = 757), twins (N = 957 pairs), and siblings (N = 950)] was conducted in 2004-2006.

The Neuroscience Project of MIDUS 2 contains data from 331 respondents. These respondents include two distinct subsamples, all of whom completed both the Project 1 Survey and the Project 4 biomarker assessment at University of Wisconsin-Madison: (1) longitudinal (n = 223) and (2) Milwaukee (n = 108). The Milwaukee group contained individuals who participated in the baseline MIDUS Milwaukee study, initiated in 2005.

The purpose of the Neuroscience Project was to examine the central circuitry associated with individual differences in affective style that represent a continuum from vulnerability to resilience, and characterize some of the peripheral consequences of these central profiles for biological systems that may be relevant to health. The primary aims were to: (1) characterize individual differences in both emotional reactivity and emotional recovery using psychophysiological measures such as corrugator electromyography and eyeblink startle magnitude, (2) characterize individual differences in brain morphology, in particular amygdala and hippocampal volume, using structural magnetic resonance imaging (MRI), (3) characterize individual differences in activity within the neural circuitry of emotion regulation using both electroencephalography and fMRI, and (4) test the ability of the central indices in this project to predict the comprehensive array of health, cognitive, psychological, social, and life challenge factors assessed in the other MIDUS projects.

To probe individual differences in emotional reactivity and recovery (a key component of regulation) the Neuroscience Project examined both psychophysiological and fMRI measures during the presentation of emotional (positive and negative) and neutral pictures, and these same measures during a post-picture period. The logic of this strategy is that continued activation during the recovery period following a negative stimulus is indicative of poor automatic emotion regulation. Respondents in the Neuroscience Project are a representative subsample of the MIDUS (Midlife in the United States) survey.

National respondents in the Neuroscience Project are a representative subsample of the MIDUS 2 survey sample (#4652).

The raw neuro-imaging data are not available through NACDA/ICPSR; please see the README file for more information about how to obtain them.

The Biomarker Project is one of multiple projects that comprise the MIDUS 3 (M3) "Integrative Pathways to Health and Illness" study. For the past two decades, the overarching objective of MIDUS has been to investigate linkages between sociodemographic, psychosocial, behavioral, and neurobiological variables to account for unfolding profiles of morbidity and mortality across the decades of adult life as well as the maintenance of good health and functional capacities. The study has facilitated analyses that pay attention simultaneously to age, gender, race, and socioeconomic variation in how psychosocial and neurobiological variables are linked. In addition, the M3 data permit longitudinal assessment of the impact of ongoing historical events, such as the 2008 economic recession, on the health of diverse-aged adults, which was also included in the MIDUS Refresher 1 (MR1) assessments. M3 included recruitment of additional twins to facilitate genomic analysis.

The M3 Biomarker Project (P4) includes assessment of multiple indicators of physiological regulation/dysregulation and health according to the basic protocol implemented in the MR1 study, which repeated and expanded the M2 biomarker protocol. The M3 protocol included bone density and body composition assessments at all sites and expansion of Actigraphy, Ankle Brachial Index (ABI) and Gait assessments to all three sites. Data were collected during a 24-hour stay at one of three Clinical Research Units (CRU).

In 1995-1996, the MacArthur Midlife Research Network carried out a national survey of over 7,000 Americans aged 25 to 74 [ICPSR 2760]. The purpose of the study was to investigate the role of behavioral, psychological, and social factors in understanding age-related differences in physical and mental health. The study was innovative for its broad scientific scope, its diverse samples (which included siblings of the main sample respondents and a national sample of twin pairs), and its creative use of in-depth assessments in key areas (e.g. daily diary of stressful experiences [ICPSR 3725] and cognitive functioning [ICPSR 3596]) on a subset of participants. A detailed description of the study and findings generated by it are available at: http://www.midus.wisc.edu.

With support from the National Institute on Aging, a follow-up of the original Midlife Development in the United States (MIDUS) sample was conducted in 2004 (MIDUS 2 [ICPSR 4652]). The daily stress and cognitive functioning projects were repeated and expanded at MIDUS 2; in addition the protocol was expanded to include biomarkers and neuroscience.

In 2013 a third wave (MIDUS 3) of survey data was collected on longitudinal participants. Data collection for this follow-up wave largely repeated baseline assessments (e.g., phone interview and extensive self-administered questionnaire), with additional questions in selected areas such as economic recession experiences. Cognitive functioning data were also collected at the same time, while data collection for the daily diary, biomarker, and neuroscience projects commenced in 2017.

Data in this collection are related to MIDUS 3 [ICPSR 36346]. Data collection for the MIDUS 3 largely repeated baseline assessments (e.g., phone interview and extensive self-administered questionnaire), with additional questions in selected areas (e.g., economic recession experiences, optimism and coping, stressful life events, and caregiving).

In 2013-2014, a second wave of cognitive assessments (Project 3) were carried out on individuals who had recently completed the MIDUS 3 phone survey (Project 1). This assessment, known as the Brief Test of Adult Cognition via Telephone (BTACT), was carried out approximately 9 years after the first wave of cognitive data collection was completed in 2004-2005. MIDUS 3 BTACT data were collected from 2,693 MIDUS 3 participants. Further, a second wave of cognitive assessments were also carried out on respondents to the MIDUS Milwaukee Wave 2 survey that was conducted in 2016-2017. BTACT data were collected from 330 Milwaukee respondents. Finally, BTACT data was collected in 2017 from another 268 respondents (called the Refielding sample) who did not complete this project during the M3 field period. This M3 BTACT dataset contains a total of 3,291 respondents. More details on the fielding of these cases can be found in the MIDUS field reports for the M3 survey [ICPSR 36346] and the Milwaukee 2 survey [ICPSR 37120].

The dataset includes 245 variables and 3,291 cases. Demographic variables in this collection include sex and age.

In 2005, 592 African Americans from Milwaukee were added to the MIDUS sample to examine health issues in minority populations (for more details, see Midlife in the United States (MIDUS 2): Milwaukee African American Sample [ICPSR #22840]). Respondents were interviewed in their homes using a Computer Assisted Personal Interview (CAPI) survey protocol and asked to complete and return a Self-Administered Questionnaire (SAQ). Afterwards these individuals were eligible for participation in the same research protocol as the national MIDUS 2 sample, including cognitive, daily stress, biomarker, and neuroscience projects.

With support from the National Institute on Aging, a second wave of survey data collection on the Milwaukee sample was begun in 2016. The survey consisted of a 2.5 hour CAPI interview followed by a 45-page mailed SAQ. CAPI survey data was collected for 389 individuals, realizing a 78 percent response rate, adjusted for mortality and other eligibility criteria. Data collection for this follow-up wave largely repeated baseline assessments, with additional questions in selected areas (e.g., economic recession experiences, childhood experience with race, etc.). Following successful completion of the CAPI and SAQ protocols, individuals were eligible for participation in cognitive, daily stress, biomarker, and neuroscience projects.

From 2004-2009, an initial follow-up of the original Midlife Development in the United States samples (MIDUS 2) was conducted with expansion of the protocol to include Neuroscience Project data collection and a sample of Black Americans from Milwaukee, WI. The MIDUS Neuroscience Project performed a second follow-up from 2017-2022 of the MIDUS Main and Milwaukee samples (MIDUS 3) on a subsample of those who completed the MIDUS 3 Survey and Biomarker Projects.

The goal was to examine indices of brain aging, function, and structure with a focus on the brain circuitry associated with individual differences in affective style, and to characterize the peripheral consequences of these central profiles for biological systems that may be relevant to health. The primary aims were to: (1) characterize individual differences in emotional reactivity, recovery, and sustaining processes using corrugator and zygomatic electromyography and eyeblink startle magnitude, (2) characterize individual differences in brain morphology and connectivity using structural magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) (3) characterize individual differences in functional activity within the neural circuitry of emotion using task and resting state fMRI, (4) calculate brain age, and (5) test the ability of these indices to predict the comprehensive array of health, wellbeing, cognitive, psychological, social, and life challenge factors assessed in other MIDUS projects. To probe individual differences in emotional processes, psychophysiological and fMRI measures of emotional responses to the presentation of negative, positive, and neutral pictures, and these same measures during a post-picture period were examined.

Emotion-influenced memory was assessed at both the psychophysiological and imaging sessions: (1) Free recall of the presented affective pictures at the end of the psychophysiological session. (2) Memory and likeability ratings for neutral faces paired with the affective pictures in the imaging task. Finally, selected tasks from the CANTAB assessed affective biases and cognitive processes important for emotion regulation.

The MIDUS Refresher study Survey (2011-2014 ICPSR 36532) recruited a national probability sample of 3,577 adults, aged 25 to 74, designed to replenish the original MIDUS 1 baseline cohort and paralleling the five decadal age groups of the MIDUS 1 baseline survey (ICPSR 2760). The MIDUS Refresher survey employed the same comprehensive assessments as those assembled on the core longitudinal MIDUS sample, but with additional questions about impacts of the economic recession of 2008-09. The MIDUS Refresher Biomarker study (2012-2016) obtained data from 863 respondents (n=746 Main sample, n=117 African Americans from Milwaukee) who completed the MIDUS Refresher Survey.

The purpose of the Refresher Biomarker Project (Project 4) parallels that of the MIDUS 2 Biomarker project (ICPSR 29282), which collected comprehensive biological assessments on a subsample of MIDUS respondents, thus facilitating analyses that integrate behavioral and psychosocial factors with biological regulation/dysregulation, broadly defined. The aim was to use such data to explicate biopsychosocial pathways that contributed to diverse health outcomes. A further theme was to examine period effects on health (mental and physical) related to the economic recession by comparing the pre-recession MIDUS sample with the post-recession MIDUS Refresher sample. A further objective of the MIDUS Refresher sample was to strengthen cross-project analyses by increasing the sample sizes available for testing hypotheses regarding the interplay of key factors (e.g., socioeconomic status, gender, psychosocial factors, biological factors) in mid- and later-life health.

Biomarker data collection was carried out at hypothalamic-pituitary-adrenal axis, the autonomic nervous system, the immune system, cardiovascular system, musculoskeletal system, antioxidants, and three General Clinical Research Centers (at UCLA, University of Wisconsin, and Georgetown University). The biomarkers reflect functioning of the metabolic processes. Our specimens (fasting blood draw, 12-hour urine, saliva) allowed for assessment of multiple indicators within these major systems. The protocol also included assessments by clinicians or trained staff, including vital signs, morphology, functional capacities including 3 dimensional gait analysis, bone densitometry, body composition, ankle brachial index, medication usage, and a physical exam. Project staff obtained indicators of heart-rate variability, beat to beat blood pressure, respiration, and salivary cortisol assessments during an experimental protocol that included both a cognitive and orthostatic challenge. Finally, to augment the self-reported data collected in Survey (Project 1), participants completed a medical history, self-administered questionnaire, and self-reported sleep assessments. For respondents at one site (UW-Madison), objective sleep assessments were also obtained with an Actiwatch(R) activity monitor.

The Midlife in the United States (MIDUS Refresher): Cognitive Project, 2011-2014 collection includes data collected as part of the MIDUS Refresher study. The MIDUS Refresher study (2011-2014, ICPSR 36532) recruited a national probability sample of 3,577 adults, aged 25 to 74, designed to replenish the original MIDUS 1 baseline cohort and paralleling the five decadal age groups of the MIDUS 1 baseline survey (ICPSR 2760). Participants in the MIDUS Refresher survey were recruited for the Brief Test of Adult Cognition via Telephone (BTACT) interview. All recruited participants who completed the initial telephone interview were invited to complete the questionnaires, and, whether or not they returned the questionnaires, were invited to participate in the Cognitive Interview. In addition to the national MIDUS Refresher sample, respondents to the MIDUS Milwaukee Refresher sample (see ICPSR 36722) were also eligible to participate in the BTACT interview. From February, 2012, through September, 2014, respondents completed the cognitive interview. For the Cognitive Project MIDUS Refresher BTACT data were collected from 2,763 MIDUS Refresher participants.

The BTACT is the first comprehensive cognitive battery--including measures of speed and reaction time--to be administered by telephone to a national sample across the adult years and into later life. It includes seven subtests: word list recall immediate, word list recall delayed, backward digit span, number series, counting backward speed task, category fluency, and an attention switching reaction time task. The Refresher cognitive project provides a rich data set to examine individual differences in cognitive functioning with a diverse national sample in terms of age, sex, socioeconomic status (income, education) and geographical region.

Demographic variables in this collection include sex and age

The MIDUS Refresher Daily Diary Project (aka National Study of Daily Experiences or NSDE) contains data from 782 respondents. The purpose of the Daily Stress Project was to examine how sociodemographic factors, health status, personality characteristics, and genetic endowment modify patterns of change in exposure to day-to-day life stressors as well as physical and emotional reactivity to these stressors.

The primary aims were:

1. To describe how the links between multiple aspects of daily stressors (e.g., frequency, content, severity) and daily physical and emotional well-being change over ten years during adulthood;
2. To examine how sociodemographic factors and personality characteristics influence change in both exposure to as well as changes in physical and emotional reactivity to daily stressors;
3. To investigate how exposure and reactivity to daily stressors correlate with physiological indicators of physical health and predict changes in global health reports; and
4. To explore the relative genetic and environmental influences mediating change in exposure and physical and emotional reactivity to daily stressors throughout adulthood.

The Daily Diary study is comprised of a subsample of the MIDUS (Midlife in the United States) Refresher, a national survey of nearly 3,600 Americans (aged 25 to 75) conducted during 2011-2014. The MIDUS Refresher survey was designed to replenish the original MIDUS 1 baseline cohort and allow the examination of period effects on health (mental and physical) related to the economic recession by comparing the pre-recession MIDUS 1 sample with the post-recession MIDUS Refresher sample. Guiding hypotheses, at the most general level, were that behavioral and psychosocial factors are consequential for health (physical and mental).

Demographic variables in this collection include sex and age.

In 2012-2013, the MIDUS Milwaukee Refresher study recruited a sample of 508 Milwaukee African American adults, aged 25 to 64, designed to replenish the Midlife Development in the United States (MIDUS 2): Milwaukee African American Sample, 2005-2006 (ICPSR 22840). This sample was also designed to increase the number of racial minorities included in the broader MIDUS study. The MIDUS Milwaukee Refresher survey employed the same assessments (demographic, psycho-social, and physical and mental health) as those assembled on the existing MIDUS sample, but with additional questions about the effect of the economic recession of 2008-09. A sample of African Americans from Milwaukee County, Wisconsin, was stratified by age, gender, and income.

Area probability sampling methods were used to identify potential respondents. Field interviewers screened households to determine if they contained any African American adults. There was additional screening to achieve an appropriate age/gender distribution in a manner similar to what was done for the original MIDUS sample (Midlife in the United States (MIDUS 1), 1995-1996 [ICPSR 2760]). Milwaukee respondents were interviewed in their homes using a 2.5-hour Computer Assisted Personal Interview (CAPI) protocol and afterwards asked to complete a self-administered questionnaire (SAQ). All measures paralleled those used in the larger MIDUS samples. In addition to successful completion of the survey, participants were asked to complete a cognitive assessment by phone. Some respondents were eligible to participate in additional MIDUS projects: daily diary assessments, biomarker assessments, and neuroscience assessments.

The MIDUS Refresher Neuroscience Project studied 138 participants from the Refresher sample. These respondents included two distinct subsamples, all of whom completed both the Survey Project and the Biomarker Project's assessment at the University of Wisconsin-Madison: the Main Refresher (n = 93) and Milwaukee Refresher (n = 45) samples.

The purpose of the Neuroscience Project is to examine the central circuitry associated with individual differences in affective style that represent a continuum from vulnerability to resilience, and to characterize the peripheral consequences of these central profiles for biological systems that may be relevant to health.

In 2011-2014, the MIDUS Refresher study recruited a national probability sample of 3,577 adults, aged 25 to 74, designed to replenish the original MIDUS 1 baseline cohort and paralleling the age groups of the MIDUS 1 baseline survey in 1995. The MIDUS Refresher survey employed the same comprehensive assessments as existing MIDUS sample, with additional questions about the effect of the Great Recession in 2008-09. Survey data were collected on demographic, psychosocial, and health and well-being information.

In 2022-2024, the second wave of survey data (MIDUS Refresher 2) was collected on longitudinal participants, including the questions (1) repeated from the Refresher 1, (2) new impacts of the COVID-19 pandemic replacing the questions related to the Great Recession in the Refresher 1, and (3) the additional questions in selected areas (e.g., AD8, IADL, family history of dementia). This new longitudinal MIDUS data allow examination of period effects on health and well-being related to the COVID-19 pandemic by comparing the pre-pandemic MIDUS Refresher 1 data with the post-pandemic MIDUS Refresher 2 data. Further, the longitudinal MIDUS Refresher datasets (Wave 1 and Wave 2) allow investigation of the two major macro-level historic events, the Great Recession and the COVID-19 pandemic, on health and well-being across various population groups in the U.S.

In 2011-2014, the MIDUS recruited a national probability sample of 3,577 adults, aged 25 to 74, designed to replenish the original MIDUS 1 (M1) baseline cohort and paralleling the five decadal age groups of the M1 baseline survey (ICPSR 2760).

The MIDUS Refresher (MR1) survey included the same comprehensive assessments as those assembled on the original MIDUS Core sample (obtained via interview and self-administered questionnaire), but with additional questions about the effect of the economic recession of 2008-09.

In 2012-2013, the National MIDUS Refresher sample was augmented with a sample of 508 Milwaukee African American adults, aged 25 to 64. This sample was designed to increase the number of racial minorities included in the MIDUS study. The MIDUS Milwaukee Refresher survey also included the same assessments as those in the Milwaukee Core sample (ICPSR 22840) and employed a personal interview. This dataset includes all known decedents from the National (ICPSR 36532) and Milwaukee (ICPSR 36722) Refresher samples, and is current for NDI records through December, 2023.

In 2008, with funding from the National Institute on Aging (NIA), baseline survey data were collected from a probability sample of Japanese adults (N=1,027) aged 30 to 79 from the Tokyo metropolitan area, resulting in the Survey of Midlife in Japan (MIDJA) [ICPSR 30822]. In 2009-2010, biomarker data was obtained from a subset (n=382) of these cases (MIDJA Biomarker) [ICPSR 34969].

The survey and biomarker measures obtained, parallel those in a national longitudinal sample of Americans known as Midlife in the United States (MIDUS) [ICPSR 4652: MIDUS 2 and ICPSR 2760: MIDUS 1]. The central objective was to compare the Japanese sample (MIDJA) with the United States sample (MIDUS) to test hypotheses about the role of psychosocial factors in the health (broadly defined) of mid- and later-life adults in Japan and the United States

In 2012, with additional support from NIA, a longitudinal follow-up of the MIDJA sample was conducted resulting in a second wave (N=657) of survey data (MIDJA 2) [ICPSR 36427].

This collection reflects data from 2013-2014, when a second wave of biomarker data was obtained from a sub-sample (n=328) of those who completed the MIDJA 2 survey. Among this group, about 75 percent (n=243) also completed the first wave of biomarker assessments.

Participants traveled to a clinic on the University of Tokyo campus where biomarker data (vital signs, morphometric assessments, blood assays, and medication data) were obtained. Participants also provided daily saliva samples for cortisol assessment and completed a self-administered medical history questionnaire, as well as a time preference questionnaire.

The medical history questionnaire included assessments of conditions and symptoms, major health and life events, nutrition/diet, and additional psychosocial measures (anxiety, depression, relationship quality, control, etc.).

The time preference questionnaire was used to collect respondents' opinions on management of money and assets given hypothetical scenarios.

Demographic variables include age, gender, and marital status.

In 2008, with funding from the National Institute on Aging (NIA), baseline survey data for the Survey of Midlife in Japan (MIDJA), April-September 2008 were collected from a probability sample of Japanese adults (N=1,027) aged 30 to 79 from the Tokyo metropolitan area (ICPSR 30822). In 2009-2010 biomarker data was obtained from a subset of these cases (ICPSR 34969).

The survey and biomarker measures obtained parallel those in a national longitudinal sample of Americans known as Midlife in the United States or MIDUS (ICPSR 2760: MIDUS 1 and ICPSR 4652: MIDUS 2). The central objective was to compare the Japanese sample (MIDJA) with the United States sample (MIDUS) to test hypotheses about the role of psychosocial factors in the health (broadly defined) of mid- and later-life adults in Japan and the United States.

In 2012, with additional support from NIA, a longitudinal follow-up of the MIDJA sample was completed. The data collection for this second wave (N=657) largely repeated the baseline assessments. The goal of the follow-up wave was to conduct comparisons of longitudinal data available from the Japanese sample (MIDJA) and the United States sample (MIDUS) to test the hypothesis about the role of psychosocial factors in predicting health changes (including biomarkers) in both cultural contexts. Cultural influences on age differences in health and well-being were also of interest.

Demographic and background information included gender, age, education, marital status, household composition, and income.