National Archive of Computerized Data on Aging

This study is maintained and distributed by the National Archive of Computerized Data on Aging (NACDA), the aging program within ICPSR. NACDA is sponsored by the National Institute on Aging (NIA) at the National Institutes of Heath (NIH).

Midlife in the United States (MIDUS 2), 2004-2006 (ICPSR 4652)

Principal Investigator(s): Ryff, Carol, University of Wisconsin-Madison; Almeida, David M., Pennsylvania State University; Ayanian, John, Harvard University; Carr, Deborah S., University of Wisconsin-Madison; Cleary, Paul D., Harvard University; Coe, Christopher, University of Wisconsin-Madison; Davidson, Richard, University of Wisconsin-Madison; Krueger, Robert F., University of Minnesota; Lachman, Marge E., Brandeis University; Marks, Nadine F., University of Wisconsin-Madison; Mroczek, Daniel K., Purdue University; Seeman, Teresa, University of California-Los Angeles; Seltzer, Marsha Mailick, University of Wisconsin-Madison; Singer, Burton H., Princeton University; Sloan, Richard P., Columbia University; Tun, Patricia A., Brandeis University; Weinstein, Maxine, Georgetown University; Williams, David, University of Michigan


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 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 II 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 II, 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. Also administered was a modified form of the mail questionnaire, via telephone, to respondents who did not complete a self-administered questionnaire.

Series: Midlife in the United States (MIDUS) Series

Access Notes

  • The public-use data files in this collection are available for access by the general public. Access does not require affiliation with an ICPSR member institution.


DS1:  M2_P1_Aggregate Data - Download All Files (154.827 MB) large file
DS2:  M2_P1_Disposition Codes - Download All Files (4.359 MB)
SAS    SPSS    Stata    R    ASCII    Excel/TSV
ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS3:  M2_P1_Main Weights Data - Download All Files (3.983 MB)
SAS    SPSS    Stata    R    ASCII    Excel/TSV
ASCII + SAS Setup    SPSS Setup    Stata Setup   
DS4:  M2_P1_Coded Text Data - Download All Files (12.61 MB)
SAS    SPSS    Stata    R    ASCII    Excel/TSV
ASCII + SAS Setup    SPSS Setup    Stata Setup   

Study Description


Ryff, Carol, David M. Almeida, John Ayanian, Deborah S. Carr, Paul D. Cleary, Christopher Coe, Richard Davidson, Robert F. Krueger, Marge E. Lachman, Nadine F. Marks, Daniel K. Mroczek, Teresa Seeman, Marsha Mailick Seltzer, Burton H. Singer, Richard P. Sloan, Patricia A. Tun, Maxine Weinstein, and David Williams. Midlife in the United States (MIDUS 2), 2004-2006. ICPSR04652-v7. Ann Arbor, MI: Inter-university Consortium for Political and Social Research [distributor], 2017-11-20.

Persistent URL:

Export Citation:

  • RIS (generic format for RefWorks, EndNote, etc.)
  • EndNote XML (EndNote X4.0.1 or higher)


This study was funded by:

  • United States Department of Health and Human Services. National Institutes of Health. National Institute on Aging (5-PO1-AG20166-04)

Scope of Study

Subject Terms:    adults, health status, life satisfaction, lifestyles, mental health, midlife, psychological wellbeing, relationships, siblings, social indicators, twins, work attitudes

Geographic Coverage:    United States

Time Period:   

  • 2004--2006

Date of Collection:   

  • 2004-01-02--2006-09-01

Unit of Observation:    individual

Universe:    The noninstitutionalized, English-speaking population of the United States.

Data Type(s):    survey data

Data Collection Notes:

The data in this collection can be linked to the following MIDUS studies by using the variable M2ID: ICPSR 2760, 22840, 25281, 26841, 28683, and 29282.

The missing value assignments for the following variables have been reduced from 9-10 digits in length to a maximum of 8 digits in length due to a limitation in Stata: B1SG17A, B1SG18A, B1SG18B, B1SG19A, B1SG21B, BASG22A, B1SG24A, B1SG25A, B1SG25B, B1SG25C, B1SG25D, B1SG25E, B1SG25F, B1SG25G, B1SG25H, AND B1SG25I.

The DDI codebook (PDF file) and the XML file (contained in a zip package) released by ICPSR were provided by MIDUS and were not changed in any way by ICPSR. These original files do not reflect any of the processing done by ICPSR.

The online analysis (SDA) file is a merged file comprised of the four datasets within this data collection. The files were merged using the variable M2ID. Users of this merged file should review the information in the "Documentation of Post-stratification Weights Created at MIDUS II," available through the ICPSR and NACDA Web sites, prior to analysis.

A document pertaining to the naming conventions for this study has been added to the collection.

The title of this study was changed from National Survey of Midlife Development in the United States (MIDUS II), 2004-2006, to Midlife in the United States (MIDUS 2), 2004-2006, on May 9, 2017.


Sample:    The respondents to this study were first interviewed as part of the NATIONAL SURVEY OF MIDLIFE DEVELOPMENT IN THE UNITED STATES (MIDUS), 1995-1996 (ICPSR 2760). MIDUS was based on a nationally representative random-digit-dial (RDD) sample of noninstitutionalized, English-speaking adults, aged 25 to 74, selected from working telephone banks in the coterminous United States. Predesignated households were selected in random replicates, one-fourth of which included a special nonrespondent incentive component. Contact persons were informed that the survey was being carried out through the Harvard Medical School and that it was designed to study health and well-being during the middle years of life. After explaining the study to the informant, a household listing was generated of people in the age range of 25 to 74, and a random respondent was selected. Oversampling of older people and men was achieved by varying the probability of carrying out the interview at this stage as a joint function of the age and sex of the randomly selected respondent. No other person in the household was selected if the respondent did not complete the interview. There was no additional sampling of cases for the longitudinal component of MIDUS II -- it was a follow-up study and attempted to recontact original MIDUS participants. More information about the MIDUS II sample can be found in the document "Descriptions of MIDUS Samples," available for download through the ICPSR and NACDA Web sites.

Mode of Data Collection:    audio computer-assisted self interview (ACASI), computer-assisted personal interview (CAPI), computer-assisted telephone interview (CATI), mail questionnaire, telephone interview

Response Rates:    Detailed information regarding the response rates for various aspects of the MIDUS II data collection is located in the following documents: "Descriptions of MIDUS Samples" and "Field Report for MIDUS II Longitudinal Sample." These documents are available for download through the ICPSR and NACDA Web sites.

Presence of Common Scales:    See the document "Documentation of Psychosocial Constructs and Composite Variables in MIDUS II Project 1" available through the ICPSR and NACDA Web sites for complete information regarding the scales for the MIDUS II data collection.

Extent of Processing:   ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:

  • Standardized missing values.
  • Created online analysis version with question text.
  • Checked for undocumented or out-of-range codes.


Original ICPSR Release:   2007-03-07

Version History:

  • 2017-11-20 This collection is being updated, per request from the PI, to reflect a title change; the corresponding downloadable files are only being updated to reflect the title change, where applicable. Additionally, an R data file is provided in this update.
  • 2012-04-18 A document pertaining to the naming conventions for this study has been added to the collection.
  • 2011-10-25 The document titled DDI codebook has been renamed Codebook.
  • 2011-10-10 Documentation has been updated.
  • 2011-07-29 The study codebook has been updated to include detailed question text.
  • 2011-04-22 The study documentation has been updated. The Aggregate dataset (DS1) has been updated. The Disposition Codes dataset (DS2) has been updated The Disposition Codes dataset is a combination of current mortality status and final disposition codes detailing the reasons for nonrepsonse to the telephone interview at MIDUS II. This combined file is a replacement of the original mortality dataset. The Coded Text dataset (DS4) is an addition to the data collection. This dataset contains qualitative text and open-ended response data. Additionally, a. xml file and corresponding .pdf codebook have been added to the collection. Lastly, further information regarding changes to the data collection and documentation can be found in the README document available for download from the ICPSR and NACDA Web sites.
  • 2007-03-22 Editorial refinements were made to the metadata.

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